Freelander 2001MY Workbook - Eng

Freelander 2001MY Workbook - Eng
FREELANDER 2001 MY
Workbook
11–16–LR-W: Ver 1
Published by Service Training
© Rover Group Limited 2000
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form, electronic, mechanical,
recording or other means without prior written permission from Rover Group Limited.
Preface
This document has been issued to support the Freelander model range 01MY. The information
contained within this document relates to the features and specification of this model.
Every effort has been taken to ensure the information contained in this document is accurate and
correct. However, technical changes may have occurred following the date of publication. This
document will not necessarily have been updated as a matter of course. Therefore, details of any
subsequent change may not be included in this copy
The primary function of this document is to support the Service Training programme. It should not
be used in place of the workshop manual. All applicable technical specifications, adjustment
procedures and repair information can be found in the relevant document published by Rover
Group Technical Communication.
Produced by:
Rover Group Limited
Service Training
Gaydon Test Centre
Banbury Road
Lighthorne
Warwick
CV35 0RG
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ii
Technical Brochure
Freelander 2001 MY.....................................................................................................
Introduction...........................................................................................................
Window lift system................................................................................................
Environmental Box ...............................................................................................
Body modifications ...............................................................................................
1
1
2
2
3
Power distribution and bus systems.........................................................................
Power distribution.................................................................................................
Introduction to Bus technology .............................................................................
CAN-Bus (controller area network) .....................................................................
Diagnostic bus......................................................................................................
4
4
5
6
8
Central control unit .....................................................................................................
Introduction...........................................................................................................
Transit mode ........................................................................................................
Self test mode ......................................................................................................
10
10
11
11
Locking and alarm systems .......................................................................................
Introduction...........................................................................................................
Single point entry..................................................................................................
Latch motor protection..........................................................................................
Alarm arming and disarming ................................................................................
Partial arming .......................................................................................................
Alarm triggers .......................................................................................................
13
13
15
15
16
17
18
Immobilisation .............................................................................................................
Engine immobilisation EWS-3D ...........................................................................
EWS-3D electronic control unit ............................................................................
Engine control module (ECM) ..............................................................................
Central control unit ...............................................................................................
Ring antenna and keys.........................................................................................
Instrument pack....................................................................................................
Emergency access ...............................................................................................
Immobilisation ECU and/or key ordering procedure.............................................
19
19
21
21
22
23
24
24
24
Instrument pack...........................................................................................................
Introduction...........................................................................................................
General.................................................................................................................
Operating Modes..................................................................................................
Speedometer........................................................................................................
Liquid crystal display (LCD)..................................................................................
Tachometer ..........................................................................................................
Fuel Level Gauge .................................................................................................
Engine coolant temperature gauge ......................................................................
Instrument illumination .........................................................................................
26
26
26
28
30
30
30
31
31
32
Heating, ventilation and air conditioning..................................................................
Heating and ventilation ........................................................................................
Heating and ventilation operation.........................................................................
Air conditioning.....................................................................................................
Refrigerant system ...............................................................................................
Air Conditioning Control System ..........................................................................
Air conditioning operation.....................................................................................
33
33
34
35
36
39
42
Contents
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Technical Brochure
Fuel burning heater ....................................................................................................
Fuel burning heater fuel pump .............................................................................
Fuel Burning Heater (FBH) Unit...........................................................................
43
43
44
K series 1.8 petrol engine ..........................................................................................
Introduction ..........................................................................................................
General ................................................................................................................
Manifolds and exhaust system.............................................................................
Exhaust System ...................................................................................................
Technical data......................................................................................................
46
46
46
50
52
53
Modular engine management system version 3 ......................................................
General ................................................................................................................
Engine control module .........................................................................................
Heated oxygen sensor .........................................................................................
Crankshaft position sensor ..................................................................................
Camshaft sensor..................................................................................................
Manifold absolute pressure sensor ......................................................................
Engine coolant temperature sensor .....................................................................
Intake air temperature sensor ..............................................................................
Engine oil temperature sensor .............................................................................
Throttle position sensor........................................................................................
Idle air control valve (Bi-polar stepper motor) ......................................................
Ignition coils .........................................................................................................
Fuel injectors........................................................................................................
Evaporative emissions purge valve .....................................................................
Alternator .............................................................................................................
Ignition switch signal ............................................................................................
Main relay ............................................................................................................
Fuel pump relay ...................................................................................................
Engine cooling fans..............................................................................................
Fuel tank level sensor ..........................................................................................
Malfunction indicator lamp ...................................................................................
Tachometer drive .................................................................................................
Vehicle immobilisation .........................................................................................
Rough road detection...........................................................................................
Fuel shut-off switch (Inertia switch)......................................................................
Throttle pedal switch (Throttle position sensor) ...................................................
Diagnostics ..........................................................................................................
On-Board diagnostics ..........................................................................................
54
54
54
55
57
58
59
60
61
61
62
63
64
65
66
66
67
67
68
69
70
70
70
70
70
71
71
72
72
KV6 ...............................................................................................................................
General ................................................................................................................
Cylinder block styructure......................................................................................
Crankshaft, sump and oil pump components.......................................................
Cylinder head components ..................................................................................
Camshaft cover and engine cover components...................................................
Lubrication circuit .................................................................................................
Crankcase ventilation...........................................................................................
Emission control...................................................................................................
Exhaust emission control ....................................................................................
Fuel delivery system ............................................................................................
73
73
74
76
79
82
84
85
86
90
90
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Contents
Technical Brochure
Cooling system.....................................................................................................
Manifolds and exhaust systems ...........................................................................
Technical data ......................................................................................................
94
95
101
Siemens 2000 Engine management system .............................................................
General.................................................................................................................
ECM .....................................................................................................................
Engine sensors.....................................................................................................
Ignition coils..........................................................................................................
Ignition timing .......................................................................................................
Fuel injectors ........................................................................................................
Idle air control (IAC) valve ....................................................................................
Evaporative emissions (EVAP) canister purge valve ...........................................
Variable intake system (VIS) valves.....................................................................
Malfunction Indicator Lamp (MIL).........................................................................
Diagnostics...........................................................................................................
102
102
104
104
111
112
113
114
115
115
115
115
M47R Diesel engine.....................................................................................................
Introduction...........................................................................................................
General.................................................................................................................
Cylinder block components .................................................................................
Sump, crankshaft and oil pump components .......................................................
Cylinder head components...................................................................................
Camshaft cover components................................................................................
Camshaft timing train components.......................................................................
Lubrication circuit ................................................................................................
Emission control ...................................................................................................
Exhaust Gas Recirculation (EGR)........................................................................
Exhaust emission control .....................................................................................
Introduction to the common rail fuel delivery system ...........................................
Fuel delivery system structure..............................................................................
Cooling system.....................................................................................................
Inlet and exhaust manifolds..................................................................................
Technical data ......................................................................................................
116
116
116
117
123
126
130
132
135
138
140
141
142
146
153
154
160
Electronic diesel control.............................................................................................
General.................................................................................................................
Engine Control Module (ECM) .............................................................................
Throttle potentiometer ..........................................................................................
Crankshaft Position (CKP) sensor .......................................................................
Camshaft Position (CMP) sensor .........................................................................
Mass Air Flow/ Inlet Air Temperature (MAF/ IAT) sensor ....................................
Boost Pressure (BP) sensor.................................................................................
Vacuum control module........................................................................................
Variable nozzle turbine.........................................................................................
Engine Coolant Temperature (ECT) sensor.........................................................
Exhaust Gas Recirculation (EGR) modulator.......................................................
Brake switch .........................................................................................................
Clutch switch ........................................................................................................
Main relay.............................................................................................................
Glow plug relay and glow plugs............................................................................
Common Rail (CR) fuel injection .........................................................................
161
161
163
164
166
167
167
169
169
169
170
171
171
172
173
174
175
Contents
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Technical Brochure
Fuel delivery – High Pressure (HP) side..............................................................
Fuel pressure regulator valve ..............................................................................
Electronic fuel injector .........................................................................................
Fuel rail pressure sensor .....................................................................................
175
176
176
177
Cruise control..............................................................................................................
Introduction ..........................................................................................................
KV6 cruise control................................................................................................
Components and their functions .........................................................................
M47R diesel cruise control...................................................................................
178
178
178
179
184
JATCO..........................................................................................................................
General ................................................................................................................
Steptronic JATCO automatic gearbox .................................................................
Torque converter..................................................................................................
Fluid cooling.........................................................................................................
Sensors................................................................................................................
Selector and inhibitor switch ................................................................................
Gear lever selector assembly ..............................................................................
Instrument Pack ...................................................................................................
Electronic automatic transmission control unit.....................................................
Main relay ............................................................................................................
Diagnostics ..........................................................................................................
Diagnostic Trouble Codes (DTC).........................................................................
Operation .............................................................................................................
Gear Shift Scheduling .........................................................................................
Lock-Up Control ...................................................................................................
Line Pressure Control ..........................................................................................
Driving Modes ......................................................................................................
Reverse inhibit .....................................................................................................
Hill mode ..............................................................................................................
Downhill recognition.............................................................................................
Cooling strategy ...................................................................................................
Engine cooling fan ...............................................................................................
Diagnostics ..........................................................................................................
Gearbox fault status.............................................................................................
Engine speed and throttle monitoring ..................................................................
190
190
191
195
199
200
205
206
210
211
214
214
215
216
218
218
219
219
220
220
220
221
221
221
221
222
Getrag 283 ...................................................................................................................
General ................................................................................................................
Intermediate reduction drive ................................................................................
Clutch...................................................................................................................
223
223
224
225
Braking system ...........................................................................................................
Foundation brakes ...............................................................................................
Anti lock braking system ......................................................................................
Anti-lock braking system ......................................................................................
Electronic brake-force distribution........................................................................
Diagnostics ..........................................................................................................
Electrical data ......................................................................................................
226
226
227
232
232
235
237
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Contents
Freelander 2001 MY
Freelander 2001 MY
Freelander 2001 MY
Introduction
Introduction
In 1997 to much acclaim Land Rover launched Freelander. This new model range saw a
significant departure from the traditional Land Rover engineering format and carried the Land
Rover brand into the medium and small segments of the four wheel drive leisure market. Again,
Land Rover has captured the leading position within the market segment and continues to develop
its position.
Freelander was something new from Land Rover. Designed to be adaptable and accessible,
broadening the appeal of the Land Rover Brand. It featured many innovative solutions designed
to create car-like ride and handling for enjoyable and adventurous driving, both on the road and
off it. Freelander is modern and contemporary, without denying its Land Rover heritage. A range
of body styles are available: the three door comes in either Softback or Hardback versions and
there is also a five door Station Wagon.
The key features of the vehicle which are carried over to Freelander 2001 model year are as
follows:
• All round independent suspension
• Power assisted rack and pinion steering
• Permanent four wheel drive
• Four channel ABS
• Electronic Traction Control.
• Hill Descent Control
• Integrated Body/Chassis design
• Use of engineering polymers and other advanced materials
• Driver and passenger airbags
• Pyrotechnic front seat belt pretensioners
• Three-point centre rear seat belt (where three rear seat belts fitted)
• Sophisticated integrated vehicle security system
• 1.8 litre K Series petrol engine
• Intermediate reduction drive
• Wide range of accessories
Major changes
The major change to Freelander 2001 model year is the introduction of new powertrain
derivatives. The familiar K1.8/PG1 has been modified to meet ECD 3 legislation and will be
supported by the new 2.5 litre KV6 engine with Jatco automatic steptronic transmission. The L
series 2.0 litre diesel engine is replaced by the BMW common rail M47R engine. The M47R is
available with both the Jatco automatic transmission and a new manual transmission the Getrag
283.
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Introduction
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Freelander 2001 MY
Other feature changes include:
• Revised anti-lock braking system (ABS) fitted as standard with hill descent control (HDC),
electronic traction control (ETC) and electonic brakeforce distridution (EBD)
• Full controller area network (CAN) bus system
• Cruise control (both petrol and diesel automatic derivatives)
• New instrument pack
• New immobilisation system - (EWS-3D)
• HEVAC upgrades including variable displacement compressor, pulse width modulated
(PWM) cooling fans and air conditioning pollen filter
• Heated seats with lumbar adjust available on driver's seat
• Electric rear windows
• One shot down on driver's window
• Revised and improved audio system including steering wheel switches
Window lift system
New features of the window lift system include rear electric windows; a one-shot down function on
the driver's window and a timer delay function allowing the electric windows to be operated for a
predetermined amount of time after the ignition has been switched 'off'. Five door derivatives have
an isolator switch located in the centre console for the rear side door windows.
The driver's window one shot facility is controlled by a window lift ECU which is located on the
driver's side 'A' post, level with the lower edge of the fascia. If driver's door window switch is
pressed for 0.2 seconds or less the window will be driven down to the full extent of its travel.
The window lift switches are located in a new position on the centre console providing easier
access and operation.
The central control unit controls the power feed to the window lift relay, located inside the
passenger compartment fusebox. The window lift relay supplies power to the driver's window lift
ECU and to the other electric window circuits directly. The output is enabled by the CCU with the
ignition 'on' (position II). When the ignition is turned 'off' a timer function of the CCU enables the
front and rear electric windows to be operated for forty seconds after ignition 'off'.
Environmental Box
The environmental 'E' box is designed to keep the temperature of the components contained
within it at the same temperature as the cabin temperature. Air is circulated from the cabin through
the 'E' box and back into the cabin.
The 'E' box is fitted to Freelander KV6 and M47R derivatives and enables there use in +50°C
markets.
The following components are contained within the box:
• Engine control module
• Automatic transmission control unit (if fitted)
• Glow plug relay (diesel only)
• Temperature sensor
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Introduction
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Freelander 2001 MY
The E-box is a container that provides a protected environment for the ECM, the glow plug relay
and the EAT ECU. An open hub, centrifugal fan powered by an electric motor ventilates the E-box
with air from the passenger compartment. Air from the E-box is directed back into the passenger
compartment. The ventilating and exhaust air is routed between the passenger compartment and
the E-box through plastic ducting and corrugated rubber hoses. Operation of the cooling fan is
controlled by a thermostatic switch in the E-box. The thermostatic switch receives a power feed
while the ignition switch is in position II. If the temperature in the E-box reaches 35°C (95°F) the
thermostatic switch closes and connects the power feed to the fan, which runs to cool the E-box
with air from the passenger compartment. When the temperature in the E-box decreases to 27°C
(80°F), the thermostatic switch opens and stops the fan. To prevent the fan seizing up in cold
climates, where it may not operate for long periods of time, the fan also receives a power feed from
the starter circuit so that it runs each time while the engine is cranked.
E-Box location
Figure 1
1. E-Box
2. Engine compartment fusebox
Body modifications
The following list identifies new features that are available with Freelander 2001 MY. Availability
will be market dependent for a number of the features:
New features
• KV6 front end extended with unique bumper covers
• Shift interlock (JATCO)
• Rear seat belt automatic locking retractors
• Front seatbelt load limiters
• Front seat belt buckle warning
• Dark tinted privacy glass
• Powerfold door mirrors
• Illuminated sunvisor
• V6 badge
• New range of alloy wheels
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Introduction
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Freelander 2001 MY
Power distribution and bus systems
Power distribution and bus systems
Power distribution
Power distribution within the vehicle and the safe delivery of that power is carried out by the
battery, the alternator, the harness and the fuseboxes. The fuseboxes protect and isolate all
systems but there is also additional protection for many individual systems contained within
individual circuits and ECU's.
Battery and alternator specification
Component
Battery
Alternator
KV6
Delphi H6
75 Ah
Denso 120 A
M47
Delphi H7
80 Ah
Valeo
115 A
K 1.8
Delphi H5
55 Ah
A/C Denso 105 A
Non A/C Denso 90A
Battery
All Freelander 2001 MY batteries are sealed for life and maintenance free. Located on top of the
battery is a condition indicator which can indicate three battery states:
1. Green - battery is in good state of charge
2. Dark (turning to black) - battery requires charging
3. Clear (or light yellow) - battery must be replaced
Fuseboxes
There are two fuseboxes fitted to Freelander 2001 MY. One is located in the engine compartment
near to the 'E' box and the other is located behind the fascia beneath the steering column. The
engine compartment fusebox contains three types of fuse:
1. Blade type fuse: Conventional pull out male type fuse used to protect circuits between 5 amps
and 30 amps
2. J-case fuse: A square shaped pull out female fuse used to protect circuits from 30 amps to
60 amps
3. Bolt down fuse: Sometimes called a fusible link they are used to protect circuits 40 amps to
250 amps
The passenger compartment fusebox contains only the conventional blade type fuses and several
relays.
Passenger compartment fusebox
Figure 2
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Power distribution and bus systems
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Freelander 2001 MY
Introduction to Bus technology
Technological advancement in vehicle electronics has led to many changes and improvements in
vehicle electrical systems. Vehicles are now fitted with systems which, although complex in
functionality, are user friendly and very reliable. Electronic control units are used to control and
monitor the operation of the systems they are fitted to and are increasingly being used to transfer
information to other system ECU's via bus technology.
An ECU is populated with solid state components, the capacity of which is matched to the
complexity of the system it has to control. ECU's receive input signals corresponding to the current
state of the system under its control. The signals to the ECU come from various sensors and
switches and these inputs dictate the outputs the ECU's send to the actuators of the system.
The powertrain electrical architecture of Freelander 2001 has been designed to exploit the
potential of its technological advances. Rather than having an ECU dedicated to its system and
unaware of the operation of other systems, the powertrain systems around Freelander 2001 are
linked together. The ECU's are linked to each other via the CAN-Bus-system, allowing
communication and exchange of information.
Control unit locations
Figure 3
1.CCU
2.RF receiver
3.Immobilisation ECU
4.SRS DCU
5.EAT ECU (automatic gearbox models )
6.ECM
7.Fuel burning heater ECU (M47R only)
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8.Cooling fan ECU
9.ABS modulator
10.Folding door mirror ECU (where fitted)
11.Window lift ECU
12.Cruise control interface ECU
13.Cruise control ECU (where fitted)
Power distribution and bus systems
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Freelander 2001 MY
The diagnostic information from each of the vehicle ECU's is accessed using TestBook via the
relevant bus system.
CAN-Bus (controller area network)
The CAN-Bus system has been developed by Bosch and is becoming the industry standard for
Europe. The CAN system is a high speed serial data bus system linked by an unscreened twisted
pair of wires: yellow/black and yellow/brown. The wires are twisted to minimise electromagnetic
interference from the signal passing down the lines to other systems in the vehicle, such as the
radio system. Both wires carry information and for CAN to operate, both signals must be present.
The CAN system is the fastest of the Bus-systems, capable of carrying 500,000 bits of information
every second. This speed is recognised as the fastest practical operating speed without a
requirement for screened cable. It is used for systems where the speed of exchange of information
is vital for their performance; engine management systems, automatic transmission and traction
control.
CAN-Bus
Figure 4
1.ABS ECU
2.Instrument pack
3.Engine management system
4.Automatic transmission control unit
5.Diesel cruise control interface unit
The CAN system consists of the main bus length and shorter stubs. The main bus length
terminates at the ECM and the IPK and must not be longer than 40 metres. Any untwisted portion
of the bus should not be longer than four centimetres. Freelander 01 MY uses a 'daisy chain' set
up with the M47R cruise interface unit tapping off the system to enable its CAN functionality. The
interface unit is a CAN based ECU which listens on the CAN system and communicates with the
diesel engine management system using multi function logic.
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Power distribution and bus systems
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Freelander 2001 MY
CAN switching
Figure 5
As stated, CAN consists of a twisted pair of wires. One line is called CAN high (CAN_H) and is
yellow and black. The other line is called CAN low (CAN_L) and is yellow and brown. CAN_L
switches between 2.5 and 1.5 volts. CAN_H switches between 2.5 and 3.5 volts.
With both CAN_H and CAN_L both at 2.5 volts there is no potential difference (voltage) between
them and this is known as the recessive state and is equivalent to logic 1.
With CAN_H switched to 3.5 volts and CAN_L switched to 1.5 volts there is a potential difference
of 2 volts between them and this is known as the dominant state and is equivalent to logic 0.
CAN_H and CAN_L always switch together and these two states are the only two possible. When
an ECU transmits a signal, it is made up of a series of dominant and recessive states generated
by the simultaneous switching of the CAN wires. The signal is a combination of the two possible
states, in effect 0 and 1, hence a digital signal.
The structure of a CAN-Bus signal is made up of several parts as shown below:
CAN message structure
Start
Identifier / Name
Control
Field
Data 0-64 Bits
CRC Test
Confirm
End of Frame
The whole message structure can vary from a minimum of 44 bits in length to a maximum of 108
bits.
The message will begin with data to signify the 'start' of the message and will also contain data to
signal the message end, 'end of frame'. The 'identifier' part of the signal will determine the content
of the signal and the priority of the signal. Arbitration is necessary when a message is transmitted
at the same time as another message.
The 'control field' carries information as to the number of bytes to follow and the data field is the
actual value of the signal being transmitted.
As an ECU transmits a signal onto CAN it also reads back the identifier on CAN. If it does not
recognise the identifier as its own this means it has lost arbitration to another signal transmission
and it stops the transmission of its own message. The ECU will wait until the Bus is quiet before
transmitting its message again.
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Power distribution and bus systems
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Freelander 2001 MY
Error checking of the signal is performed by the cyclic redundancy check (CRC). All the bits that
make up the signal are assembled into an algorithm and this is sent as the CRC part of the signal.
The receiver ECU will assemble the signal into the same algorithm and the result should match
the CRC part of the signal. If they do not match, an error is recognised and the message is ignored.
No acknowledgement (confirm) is given to the erroneous message. Because the ECU which
transmits the message is also waiting to receive an acknowledgement, it recognises that the
message is faulty and re-transmits the message. Calculations for the amount of error messages
which escape these checks have shown an average of 1 error per 10,000,000,000,000 messages
manages to get through.
For correct operation of the bus, the bus line must be terminated at both ends (ECM and IPK) with
a resistor of nominal value 120 ohms, connected between CAN_H and CAN_L. These
terminations ensure that bit errors due to signal reflections are avoided.
Fault finding
In trying to diagnose and locate a fault on the CAN-Bus or any of its associated components a
logical approach should be used. Examples:
• Are the tachometer and coolant gauges working? If either is working, this indicates the CAN
link from the ECM to the IPK is operating.
• Does the 'park, reverse, neutral, drive and low (PRNDL) display show the current gear on the
IPK? If it does, this indicates that the CAN link from the automatic transmission control unit to
the IPK is operating.
• During the start up bulb check, the HDC warning lamps in the IPK illuminates for
approximately two seconds and then extinguish. If this occurs it is an indication that the CAN
link from the ABS ECU to the IPK is operating.
Note: TestBook must be used to diagnose the CAN system. It is a complex interconnected
system and TestBook will assist the operator through the diagnostic route.
ECU's are very reliable and ECU failures rare. Wiring faults and poor connections are more
common and the symptoms of the fault will vary with the location and severity of the fault. Faults
on the system can be diagnosed logically by observing the symptoms and using a process of
elimination. TestBook will guide the operator through the process.
If either CAN_H or CAN_L short to ground or short against each other, the CAN-Bus will not
function and, therefore, communication will not take place. If a break appears in one of the lines,
diagnostic equipment may be used to interrogate each ECU and find out what it is receiving and
what it is not. When the CAN system is inoperative, each system ECU will operate independentlysome in a default 'limp home' mode.
When repairing a section of harness care must be taken with the CAN twisted pair of wires. It is
important that the twisted pair should not be unwound more than 3 - 4 cm.
Diagnostic bus
The diagnostic buses connect the diagnostic socket to the ECU's on the CAN bus and to individual
system ECU's. The diagnostic buses enable fault diagnosis, system testing and vehicle
configuration. The diagnostic socket is located above the transmission tunnel. On RHD vehicles
the connector is situated to the left of the centre console, and on LHD vehicles to the right of the
centre console.
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Power distribution and bus systems
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Freelander 2001 MY
ISO 9141 K line
The ISO 9141 K line connects the diagnostic socket to the majority of the ECU's fitted to the
vehicle. The protocol used means that non TestBook diagnostic equipment, such as scan tools,
can be used to access SRS and emission related faults stored in the ECU memories.
DS2 Bus
The DS2 bus connects the diagnostic socket to the EWS-3D ECU. The protocol used means that
only TestBook can communicate with the immobilisation system.
Diagnostic set up
Figure 6
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Power distribution and bus systems
9
Freelander 2001 MY
Central control unit
Central control unit
Introduction
The central control unit (CCU) is used to control several systems fitted to Freelander is attached
to the passenger compartment fusebox which is beneath the steering column. It is a similar unit
fitted to existing Freelander models but with some functional differences.
This CCU controls the following vehicle systems:
• Vehicle locking and alarm system
• Interior lamps
• Rear fog lamps
• Tail door window operation
• Audible and visual warnings
• Front and rear wipers
• Heated rear window
In addition, the CCU also incorporates the following features:
• Timer Control
• Programmable Features
• Window lift enable
• Transit mode
Figure 7
1.Passenger fusebox connector
2.Passenger fusebox connector
3.Connector C0428
10
Central control unit
4.Connector C0429
5.Connector C0430
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Freelander 2001 MY
Transit mode
To help prevent battery discharge in transit the CCU can be programmed, using TestBook, into
'transit mode'. In transit mode many vehicles systems and system features are disabled. The
minimum number of features are enabled allowing the vehicle to function safely. A specific
warning sound is emitted by the CCU when the vehicle is in transit mode with the ignition 'on' and
the engine not running.
The following functions are disabled in transit mode:
• RF receiver power
• Central door locking
• Interior lamps
• Tail window
• Tail door actuator
Self test mode
The CCU can be put into self test mode to enable the inputs and outputs from the CCU to be tested
for correct functionality without the need for TestBook. To put the CCU into self test mode the
ignition should be off with the vehicle unlocked and unarmed and the following sequence must be
followed:
1. Turn the ignition 'on'
2. Press and hold the rear fog switch 'on'
3. Turn the ignition 'off'
4. Turn the ignition 'on'
5. Release rear fog switch within four seconds of ignition 'on'
On successful entry to the self test mode the sounder will sound for 0.8 seconds and the courtesy
lamps will illuminate for 0.8 seconds.
When testing an input, for example a door open switch, on successful receipt of the input the CCU
will sound the sounder for 0.8 seconds and illuminate the courtesy lamps for 0.8 seconds.
Outputs are tested in sequence using the CDL lock switch to progress through the outputs. A CDL
unlock requests repeats the last test. Outputs are either operated continuously until the CDL lock
switch is released, or operated in a pulsed fashion until the next operation of the CDL lock switch.
Output formats are described in the table 'Self test outputs'.
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Self test outputs
Output
Rear fog lamps
Lock
Superlock
Unlock
Front wiper
Alarm LED
Volumetrics
Horn
BBUS
Heated rear window
Tail window down
Tail door actuator
Tail window up
Rear wiper
Hazard lights
Door open warning lamp
Seatbelt warning lamp
Handbrake warning lamp
Test type
Continuous
Pulsed
Pulsed
Pulsed
Continuous
Continuous
Continuous
Pulsed
Pulsed
Pulsed
Pulsed
Pulsed
Pulsed
Continuous
Continuous
Continuous
Continuous
Continuous
Self test mode is exited upon ignition 'off', if oil pressure is sensed (engine running) or if the vehicle
speed exceeds 1kph.
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Locking and alarm systems
Locking and alarm systems
Introduction
In this document reference is made to various vehicle locked states. For clarity the following terms
will be used: CDL locked, locked and superlocked. The term “CDL locked” will be used to refer to
the condition attained following operation of the CDL switch. The term “locked” will be used to refer
to the state attained following a successful key lock operation. The term “superlocked” will be used
to refer to the state attained following a successful key superlock operation, or a remote lock
operation.
Figure 8
1.Bonnet switch
2.Door latches
3.Tail door latch
4.Alarm LED
5.Remote handset
6.RF receiver
7.Body control unit
8.Volumetric sensor
9.Driver's door key barrel switch
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10.Ignition switch
11.CDL switch
12.ABS ECU
13.Immobilisation ECU
14.Horn
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Freelander 2001 MY
Locking
On all models a CDL switch is mounted in the centre console. This switch allows the occupants to
centrally lock the vehicle without arming the alarm, (similar to conventional sill lock). The vehicle
can also be centrally unlocked from the switch, providing the alarm is disarmed. The vehicle will
not centrally lock from the CDL switch if the inertia switch is in the tripped state. In addition, the
CCU will automatically unlock all doors from the CDL locked state, in cases where it detects the
inertia switch moving to the tripped state whilst the alarm is disarmed.
Key & Remote Handset Locking
In addition to the CDL switch, the vehicle can be locked and unlocked using the door key or the
remote handset. The precise way in which a vehicle responds to a key or remote handset input,
with regard to vehicle locking/unlocking and alarm arming/disarming, will depend upon the
programmed state of the CCU.
The programmed state of the CCU will be configured automatically when the vehicle's Market
Option is set. The Market Option selected is determined by territory. New vehicles are
programmed during the manufacturing process. In service TestBook must be used to set the
Market Option. Once the Market Option has been set the CCU will function according to a
predetermined strategy. Some features within these strategies will be fixed, whilst a number will
remain selectable, e.g. the precise locking and unlocking functionality.
In summary, vehicles can be:
• CDL Locked = vehicle locked via CDL switch
• Key Locked = turn the top of the key towards the rear of the vehicle once
• Key Super Locked = turn the top of the key towards the rear of the vehicle twice (note: the
second turn must be made within 1 second of the first)
• Remote Locked (provides super lock) = single press of the lock button on the remote handset.
Additional Locking Information
It should be noted that any CDL or arm request made using the key or the remote handset will be
ignored while the ignition is 'on' (although the driver' s door will mechanically lock in response to
a key lock attempt). In addition, if any of the passenger compartment doors are open when a
superlock request is received, then the system will only attempt to lock.
In line with the functionality of other Land Rover products, whenever the inertia switch is tripped,
while the ignition is 'on' and the alarm is disarmed, all the doors will be unlocked (irrespective of
their current locked state). Subsequent attempts to lock the doors will be then be inhibited until the
ignition is switched 'off' and the driver's door is opened and closed and the inertia switch is reset.
Tail door release, carried out by way of the exterior door handle, can be achieved while the vehicle
is in the unlocked and disarmed state. The CCU will inhibit operation of the tail door release
mechanism if the vehicle is travelling at a speed greater than approximately 5 km/h. The CCU
receives a vehicle speed input signal from the ABS ECU.
The driver's door latch is designed to mechanically inhibit slam locking. If it is necessary to
externally lock a vehicle without arming the alarm, then the driver' s door must be sill locked and
then the vehicle must be slam locked using a passenger door.
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In order for the system to respond to a remote handset lock or unlock request, the handset must
be synchronised with the CCU. It will become unsynchronised with the CCU in circumstances
where the power supply to either the remote handset or to the vehicle is lost.
To re-synchronise a remote handset with the CCU, press the lock or unlock button five times, or
any combination of both buttons five times, in succession with the ignition 'off'.
Single point entry
An additional feature, referred to as Single Point Entry (SPE), is selectable on all models. This
feature is designed to enhance the security of the vehicle and its user. SPE will operate when
unlocking the vehicle from the superlocked state using the remote handset. The remote handsets
transmit a coded frequency signal. This signal is received by a unit located on top of the instrument
pack. This unit transmits the lock/unlock information directly to the ECU, which will respond
accordingly.
Receiver location
Figure 9
1.RF Receiver
In such circumstances, a single press of the unlock button will cause the driver' s door to fully
unlock and the passenger's doors to change from the superlocked state to the locked state.
Access to the vehicle's interior will be permitted through the unlocked driver's door, but not through
any of the passenger's doors.
Latch motor protection
The side door latches used on Freelander models are innovative units which have been jointly
developed by Land Rover and BMW. The units are unique in their design and are shielded for
protection. To further enhance vehicle security and reduce complexity all switches, actuators and
electrical systems are integrated into the latch assembly.
To prevent damage occurring to the door latch motors through continual operation, the system
incorporates a Latch Motor Protection feature. This means the CCU will only allow a maximum of
eight changes of state, i.e. a change from locked to unlocked, or from super locked to locked, to
occur within 16 seconds.
The CCU will suspend operation of the latch motors if more than eight changes of state are
requested within this period. The latch motor operation will always be suspended in the unlocked
state and therefore in some circumstances, nine changes of state will be permitted. Once
suspended, the latch motor operation will be suspended for a total of 16 seconds.
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Locking and alarm systems
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Freelander 2001 MY
Alarm arming and disarming
It should be noted that although the vehicle can be locked and unlocked from the CDL switch in
the centre console, the alarm cannot be armed or disarmed from this switch. The precise response
to an arming action will vary according to the selected Market Option and the programmed state
of the CCU.
Perimetric protection
Perimetric protection refers to the protection offered against an illegal intrusion through any of the
vehicle's hinged panels and by removal of roof. The term perimetric is derived from the word
perimeter, meaning an object's boundary. Perimetric protection is achieved by monitoring the
state of the hinged panels and the roof, once the alarm has been armed. The panel open switches
on the driver's door, passenger doors, tail door, bonnet and roof are all monitored by the CCU. If
a panel opens once the alarm has been armed, then the alarm is triggered. The door switches are
incorporated into the door latch assemblies.
Perimetric protection is activated once a valid arm request is received. If any panel is “open” when
perimetric protection is activated, other than the roof, then the system will be armed in the partially
armed state (see Partial Arming).
Volumetric protection
Volumetric protection refers to the protection provided to the vehicle' s interior. The volumetric
sensor monitors this area and will trigger the alarm if it detects any unauthorised movement, whilst
the alarm is armed appropriately.
In certain circumstances, e.g. when the vehicle is parked with a window open, the vehicle may
need to be secured without the volumetric protection armed. This requirement can be catered for
by using the appropriate locking procedure, as previously described.
Volumetric protection is a desirable feature of any vehicle security system and provides a high
level of protection against theft. However, it can be the cause of considerable customer
annoyance, and has a generated a reputation for causing false alarm triggers. In recognition of
this, a number of precautions have been taken on Freelander derivatives to prevent accidental or
nuisance triggering occurring. These precautions include a settling period following system
arming, a minimum trigger signal duration and a volumetric “gain” setting, specifically suited to the
vehicle body style. The following describes the triggering conditions in more detail:
• Following a suitable arm request, the CCU will refuse to act upon any movement detect signal
supplied by the volumetric sensor, until a period of 15 seconds has elapsed. This gives
sufficient time following door closure etc.
• Once armed the CCU will only trigger the alarm if a valid movement detect signal, i.e. a signal
of at least 50 milliseconds duration, is received from the volumetric sensor. This ensures that
spurious one-off movements are suitably ignored.
• If the alarm has been triggered (by any means), the CCU is programmed to ignore any
movement detect signal supplied by the volumetric sensor for the duration of the alarm
sounding period, i.e. 30 seconds. At the end of this period, the CCU will initiate another 15
second settling period, unless the maximum number of 10 alarm triggers has been reached
since the last alarm arming, before it resets volumetric protection.
• A volumetric gain setting, suited to the body style of the vehicle will be issued by the CCU to
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the volumetric sensor. This setting is designed to avoid under/over sensitivity. The vehicle
body style is automatically deduced by the CCU from the VIN stored in its memory. If required
the setting can be tuned using TestBook.
Partial arming
In circumstances where an attempt is made to arm the alarm when the vehicle is not fully secure,
i.e. one or more of the hinged panels is open at the time when the CCU receives the arm request,
the alarm will enter the partially armed state.
The partial arming feature is designed to maximise the level of protection provided to the vehicle
in such circumstances. The system achieves this by evaluating which panel (or panels), is open
at the time when the alarm is armed, and subsequently activating as much of the alarm as is
possible. In addition to the circumstances described above, the partial arming feature also enables
the system to maximise the level of protection it provides in the event of a failure of one (or more)
of the panel open switches or their respective wiring.
Freelander derivatives are able to enter four slightly different partially armed states. The precise
partially armed state entered is determined by which panel is open. The four different states are
defined as follows:
1. Alarm armed with the driver's door open:If the vehicle enters the partially armed state due
to an open driver's door, then the CCU will suspend activation of super locking and volumetric
protection and will continue to monitor the panel left open. All other functions of the alarm
system will be fully armed.
2. Alarm armed with the passenger door or doors open: If the vehicle enters the partially
armed state due to an open passenger door, then the CCU will suspend activation of super
locking and volumetric protection and will continue to monitor the panel left open. All other
functions of the alarm will be fully armed.
3. Alarm armed with the tail door open: If the vehicle enters the partially armed state due to
an open tail door, then the CCU will allow activation of super locking, will suspend activation
of volumetric protection and will continue to monitor the panel left open. All other alarm
functions will be fully armed.
4. Alarm armed with the bonnet open: If the vehicle enters the partially armed state due to an
open bonnet, then the CCU will allow activation of super locking and volumetric protection,
and will continue to monitor the panel left open. All other alarm functions will be fully armed.
When an attempt is made to arm the alarm with one or more panels open, i.e. when the vehicle
enters the partially armed state, a number of visual and audible warnings are provided to inform
the vehicle user of the armed state. The precise warnings provided will be dependent upon the
Market Option selected and the programmed state of the CCU.
An audible mislock warning sound may be given on some vehicles. This warning will be generated
either by the vehicle' s horn, or by the BBUS (Battery Backed Up Sounder). If the warning is
generated by the horn then it will be a single sound of approximately 20 milliseconds duration. In
cases where the BBUS generates the warning then it will be a single sound of approximately 100
milliseconds.
Two forms of visual indication may be provided when the vehicle enters the partially armed state.
Firstly, there will be no fast flash from the alarm LED, immediately following entry of the armed
state. Secondly, there will be no flash at all from the hazard warning lights, immediately following
entry of the armed state.
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Freelander 2001 MY
To further enhance vehicle security, the CCU is programmed in such a way, that it allows a vehicle
which has been armed in the partially armed state, to automatically “upgrade” to the fully armed
condition. The CCU will initiate this change of state if it senses that the panel, that originally caused
the mislock, has been securely closed. With the exception to partial armed states caused by an
open driver' s door, the CCU does not require a further arm request to upgrade to the fully armed
state.
In circumstances where the partial armed state was caused by an open driver's door the CCU will
require a further arm request. If a driver's door is subsequently closed after causing a mislock, then
perimetric protection will be automatically extended to the driver' s door. However, because the
locked state of the door is not automatically upgraded, i.e. it remains in the CDL state, then
volumetric protection will not be armed, even if it was originally requested.
Alarm triggers
When the alarm is set in the fully armed state it will be triggered by the CCU if it receives any of
the following input signals:
• Bonnet opening.
• Tail door opening.
• Any side door opening
• Ignition switched on.
• A valid movement detect signal from the volumetric sensor (when volumetric protection
armed)
• Removal of the roof (if it was in place when the alarm was armed)
In response to a valid alarm trigger input, the CCU will activate audible and visual warnings for a
maximum duration of approximately 30 seconds. The precise type of warning generated will vary
according to the Market Option selected and the CCU' s programmed state.
When set, the audible warning will be provided by the vehicle' s horn, by the alarm BBUS, or by
both. The warning will either be continuous, or will be pulsed at 0.5 second intervals, i.e. 0.5
seconds on, off for 0.5 seconds, on for 0.5 seconds repeated. The visual warning will be provided
by the hazard lights and will be pulsed at the same frequency, if set.
The CCU will trigger the alarm up to 10 times in any armed period. It will not trigger the alarm more
than 10 times during this period, even if it receives further valid alarm trigger input signals.
The CCU incorporates a memory buffer. This enables the CCU to record the cause of the four
most recent alarm triggers. Using this feature, the CCU can be interrogated via TestBook to
establish precisely which input, or inputs, caused the CCU to trigger the alarm on the last four
occasions.
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Immobilisation
Immobilisation
Engine immobilisation EWS-3D
The immobilisation system used on Freelander 2001 MY is referred to as EWS-3D (Elektronische
Wegfahrsperre). The main function of the system is to prevent unauthorised starting of the vehicle
by creating a secure interface which cannot be copied or bypassed in any way. It also checks
systems to ensure that the vehicle is in a safe condition for starting. Immobilisation is carried out
by disabling the starter motor and by preventing engine fuelling via the ECM. Although the EWS3D system uses components in common with the locking and alarm system it is a stand alone
system.
EWS-3D component layout
Figure 10
1.EWS-3D ECU
2.Ring antenna
3.Key
4.IPK
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5.ECM
6.Automatic transmission position switch
7.Starter motor
8.CCU
Immobilisation
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Freelander 2001 MY
When a key is inserted in the ignition, a three stage check is carried out. Each key has a unique
identification number and this is sent by the key transponder to the EWS-3D ECU. A password
unique to the key is used by the EWS-3D ECU to communicate with the transponder. The final
stage of the key identification is the confirmation that the rolling code from the transponder
matches with the EWS-3D ECU rolling code. Once the EWS-3D has confirmed that a valid key is
requesting the starting of the vehicle, it will energise the starter motor relay and inform the ECM
that starting has clearance by sending the correct code to the ECM.
The EWS-3D ECU controls the starting of the vehicle by communicating with the ECM via a
unidirectional data line. The EWS-3D also controls the operation of the starter motor via control of
a starter motor relay. This relay is internal to the EWS-3D ECU.
Control block diagram
Figure 11
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EWS-3D electronic control unit
The EWS-3D ECU is located behind the centre of the fascia and is secured by two fixings. The
ECU arrives from the supplier as a blank unit and is programmed with a starting code during
vehicle manufacture. This code has to be learnt by the ECM and this programming is also carried
out during the manufacture of the vehicle. This starting code is then used as a base point for the
rolling code by both the EWS-3D and the ECM.
The EWS-3D electronic control unit governs the overall immobilisation and re-mobilisation of the
vehicle. Without it receiving a valid signal from a key transponder it will inhibit starting of the
vehicle. The starter motor will be disabled and the ECM will not initiate fuelling of the vehicle. Each
key has its own identity and the EWS-3D is capable of supporting up to ten keys.
When all the key slots have been used and more keys are required, the EWS-3D must be removed
and a new EWS-3D fitted. Therefore, a maximum of 10 keys per vehicle are available at any given
time. When new keys are supplied, they arrive ready for use with the vehicle, having been preprogrammed with the relevant coding. This coding relates to a new slot in the EWS-3D ECU. The
ECU is capable of recognizing the first use of the new key and initiates the rolling code transfer
from then on.
The EWS-3D can communicate with the different types of engine management systems used by
Freelander 2001 MY using the same protocol. The EWS-3D ECU also uses information from other
vehicle systems which can affect system functionality: It uses a 12 volt signal from the central
control unit to ascertain the locking status of the vehicle and it derives the engine speed from the
instrument pack. On vehicles fitted with automatic transmission, there is an input from the Park/
Neutral switch which must be present before the EWS-3D allows re-mobilisation of the vehicle.
If a fault occurs with the EWS-3D ECU a replacement is available only through a recognized
dealership, which will follow a strict process for the replacement of immobilisation components.
Here, the relevant information for every EWS-3D ECU is stored against the vehicle identification
number in a database. This information cannot be read directly from the EWS-3D ECU using
TestBook or any other diagnostic tool. At the appropriate centre this information is accessed and
is programmed into the replacement EWS-3D ECU. It will arrive at the dealership ready for fitment
to the vehicle. Once the replacement part has been fitted to the vehicle, TestBook will be required
to re-synchronise the EWS-3D ECU with the engine control module.
EWS-3D also incorporates a starter motor protection function. When the engine speed exceeds a
predetermined value, a starter relay inside the EWS-3D ECU is disabled. This relay is in series
with the main starter motor solenoid and therefore when disabled cuts off the power supply to the
starter motor. This prevents destruction of the starter motor in the event of a sticking ignition
switch.
Engine control module (ECM)
The EWS-3D ECU is capable of working with the three different engine control modules fitted to
Freelander 2001 derivatives. The KV6 2.5 litre engine use a Siemens 2000 engine management
system. The K1.8 uses Rover modular engine management system (MEMS 3). The diesel M47
uses the digital diesel electronic (DDE 4.0) engine management system.
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Freelander 2001 MY
Siemens 2000 engine control module
Figure 12
Each ECM arrives from the supplier in a blank condition. (i.e. without a starting code base point).
During the manufacture of the vehicle, there is a process carried out whereby the ECM learns the
starting code from the EWS-3D ECU. This process means that the swapping of the ECM or the
EWS-3D ECU from one vehicle to another is not possible because the correct code will not be
present in both ECU's. The ECM will allow starting of the vehicle only on reception of a valid code
from the EWS-3D.
Each ECM can learn only one starting code. For it to learn another it must first be blanked by the
supplier. A new ECM will be required in most circumstances and TestBook will be needed to
transfer the codes from the EWS-3D ECU to the blank ECM.
Central control unit
The main function of the CCU in the immobilisation of the vehicle is to provide the EWS-3D with
the locking status of the vehicle. When the vehicle is in a superlocked, or alarm armed state the
CCU sends a 12 volt input to the EWS-3D ECU. The vehicle will not start in a superlocked state
or if the alarm is armed.
If, upon receiving a valid key signal, the EWS-3D ECU receives a signal from the CCU that the
vehicle is superlocked or armed state, the starting process will be suspended momentarily. The
EWS-3D will then send a 12 volt output pulse informing the CCU of the mobilised status of the
vehicle. The CCU will then change the vehicle from the superlocked state (and/or disarm the
alarm) to an unlocked state. The 12 volt input to the EWS-3D ECU from the CCU is then removed
and starting of the vehicle can then take place.
Superlocking of the vehicle is carried out by pressing the remote lock button located on the
keyhead. It is possible to inadvertently press this button prior to inserting the key in the ignition.
The car would then be in the superlocked state and intervention is necessary to prevent starting
and driving of the vehicle in this state.
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Ring antenna and keys
The ring antenna is clipped onto the ignition key barrel. When the key is placed in the ignition and
switched to auxiliary position, the ring antenna energises the transponder in the key. This is
achieved by induction using a 125 KHz frequency power supply from the EWS-3D ECU. This
enables transfer of data to take place to and from the transponder in the key.
The transponder has to impart its unique identification number and a valid rolling code. When a
valid key signal is read, the vehicle can be started and a new rolling code is written to the
transponder for the next operation by the EWS-3D ECU.
Ring antenna
Figure 13
The key is made up of a mechanical blade and a transponder. The key blade has an external
mechanical waveform. The data for the transponder and waveform is stored on a database in
Germany. The transponder chip consists, primarily of a wireless electrical erasable programmable
read only memory (EEPROM). This can be written to and read from by the EWS-3D ECU. The
range for communication between the ring antenna and the transponder is 2 centimetres.
Identification data is programmed into the blank transponder during vehicle manufacture. Each
transponder is matched with one of the 10 key slots contained in the EWS-3D ECU. Once it is
programmed it cannot be overwritten.
Codes for all 10 slots are programmed randomly into the EWS-3D ECU during manufacture of the
vehicle. Two of these slots are taken up immediately by the two keys which are coded during
vehicle manufacture for the vehicle's initial owner. The data and codes for each of the 10 slots are
stored in a database at Dingolfing in Germany. When a new key or lock set is required it must be
processed through a recognised dealership, which will order the new component. The relevant
data will need to be accessed from Dingolfing, Germany.
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Freelander 2001 MY
If a key is lost, the slot it is addressed to should be disabled to prevent unauthorised starting of the
vehicle. This is carried out using TestBook and requires all available valid keys to complete the
process. This way, TestBook can read the identity of all the keys still available and can disarm the
slot of the missing key. If the key is subsequently found, the process can be reversed and the slot
made valid again.
A valid key is required to be in the ignition to disable/re-enable a key slot and it is not possible to
disable the key slot of the key in the ignition. This makes it impossible to accidentally disable all
key slots using TestBook, which would immobilise the vehicle.
Note: The EWS-3D drive for the ring antenna is not capable of carrying battery voltage and
care must be taken when fault finding and probing the system otherwise permanent
damage to the ECU may result.
Instrument pack
The instrument pack supplies the EWS-3D with the vehicle engine speed, converted from a CAN
signal into a pulse train compatible with the EWS-3D ECU. This is used by the EWS-3D starter
motor protection feature which isolates the starter motor when the engine speed reaches a
predetermined threshold.
Emergency access
There is no emergency key access (EKA) facility with Freelander 2001 model year. Any key will
facilitate entry into the vehicle, even if the CDL system is non functional. Re-mobilisation of the
vehicle will only be possible with a valid key in the ignition, with a working transponder and with
the valid codes.
Immobilisation ECU and/or key ordering procedure
The immobilisation system is a highly secure system and to maintain security, the supply of spare/
replacement keys and immobilisation ECU's is restricted to franchised dealers only. The EWS-3D
ECU is non serviceable and failure of any of its internal parts means a replacement EWS-3D ECU
has to be ordered. Unlike keys, an ECU identical to the original can be ordered making it possible
to use the existing keys, reducing further cost.
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Key and ECU ordering procedure – All markets (except Japan)
Each dealer must adhere to the following procedure when ordering keys and/or immobilisation
ECU's.
1. The dealer receives a request from the customer for a spare/replacement key or a
replacement immobilisation ECU and key set.
2. The dealer must request from the customer proof of ownership and Vehicle Identification
Number (VIN). This may be in the form of a registration document for example. If proof of
ownership cannot be supplied, the dealer must not proceed with ordering keys.
3. The dealer must raise a Vehicle Off Road (VOR) order quoting the VIN and the part number
of the part(s) required.
4. The dealer must pass the VOR order to the corporate wholesaler, European distribution
centre or importer on the Unipart parts ordering system before 12:45 pm for next day delivery.
5. Unipart will validate the VIN and, if correct, will send an order to BMW GB on the Direct
Factory Supplier (DFS) system before 1:00 pm for the same day delivery to Unipart. If Unipart
find the VIN to be incorrect, they will contact the dealer to revalidate the VIN.
6. BMW GB record the order and pass it to BMW AG in Dingolfing, Germany who interrogate
their database to establish that the VIN is valid. From the database, BMW AG confirm that
immobilisation codes remain available.
7. If no codes are available, the order is returned to BMW GB who inform Unipart that all
available codes have been used and that a new immobilisation ECU and key set is required.
Unipart inform the corporate wholesaler, European distribution centre or importer on a parts
information sheet that order has been rejected and reason for rejection. The corporate
wholesaler, European distribution centre or importer inform the dealer who will advise the
customer that a new immobilisation ECU and key set is required. If customer agrees, then the
ordering procedure is repeated from step 3.
8. BMW AG will establish mechanical and electrical key configuration, update the database and
create a bar code order form from which the spare/replacement key or immobilisation ECU
and key set is made.
9. BMW AG will pass the completed order form to the BMW GB key cutting centre who use the
bar code to produce the new keys or new immobilisation ECU and key sets.
10. BMW GB will despatch the part(s) to Unipart at circa 3:30 pm on the same day in order to get
the parts on the Unipart overnight VOR delivery.
11. In the UK market, Unipart will despatch the part(s) to the corporate wholesaler overnight to
arrive circa 8:30 am next day. The corporate wholesaler will deliver the part(s) to the dealer
at circa 12:00 pm on the same day.
12. In ROW markets, Unipart will despatch the part(s) to the European distribution centre or
importer next day to arrive by 12:00 pm the following day. The European distribution centre
will deliver the part(s) overnight to arrive at the dealer at circa 8:30 am the following day. In
importer markets, courier delivery times to the dealer can be typically 5/6 days for South
America/Asia and 8/12 days for Australia.
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Immobilisation
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Freelander 2001 MY
Instrument pack
Instrument pack
Introduction
The primary function of an instrument pack (IPK) is to provide the driver with continuously updated
information about the vehicle and to indicate faults as they occur, usually by illuminating a warning
lamp. The IPK fitted to the Freelander 2001 is an intelligent unit controlled by a microprocessor
and acts as the gateway for the CAN-Bus-system.
The IPK is designed to display information quickly and unambiguously. For this reason, the IPK
has a central and prominent position within the driver's field of vision, requiring only the slightest
eye adjustment to access the data displayed. The IPK uses a combination of analogue and digital
displays combining new technology with proven effective display gauges.
General
The instrument packs fitted to all Freelander models are similar, with the only differences being
the mph or km/h speedometer, odometer readings, tachometer maximum rev/min band and
certain warning lamps.
Freelander 2001 MY instrument pack (petrol)
Figure 14
1.Fuel level gauge
2.Tachometer
3.LH direction indicator warning lamp
4.Headlamp main beam warning lamp
5.RH direction indicator warning lamp
6.Speedometer
7.Engine coolant temperature gauge
8.Rear fog lamp warning lamp
9.Trailer direction indicator/hazard failure
warning lamp
10.Trip counter reset button
11.Glow plug warning lamp
12.Ignition/No charge warning lamp
13.Engine malfunction warning lamp
14.Liquid Crystal display (LCD)
15.Overspeed warning lamp
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Instrument pack
16.SRS warning lamp
17.Seat belt warning lamp
18.Alarm LED
19.Low oil pressure warning lamp
20.Handbrake and brake system warning
lamp
21.Malfunction Indicator Lamp (MIL)
22.Hill descent Control (HDC) active
warning lamp
23.HDC failure warning lamp
24.Cruise control active warning lamp
25.Anti-lock Braking System (ABS)
warning lamp
26.Traction control active warning lamp
27.Low fuel level warning lamp
28.Hazard flasher warning lamp
29.Door open warning lamp
Service Training
11-16-LR-W: Ver 1
Freelander 2001 MY
The instrument pack is a totally electronic device receiving electrical signals from sender units and
CAN messages from the Engine Control Module (ECM), ABS modulator ECU and the Electronic
Automatic Transmission (EAT) ECU and transposing them into analogue gauge readouts and
warning lamp illumination.
The instrument pack is connected to the fascia harness by connectors C0230 and C0233 which
provide all input and output connections for instrument pack operation.
Freelander 2001 MY instrument pack (petrol) rear
Figure 15
1.Connector C0230
2.RF receiver
3.RF Receiver connector
4.Connector C0233
5.Panel illumination bulb (3 off)
6.Instrument pack rear housing
A Printed Circuit Board (PCB) is located on the rear of the pack. The analogue displays, warning
lamps and the LCD are integral with the PCB. No internal components are serviceable.
The instrument pack features the following displays:
• Tachometer - large analogue display
• Speedometer - large analogue display
• Fuel gauge - small analogue display
• Engine coolant temperature gauge - small analogue display
• Odometer, trip meter - Liquid Crystal Display (LCD)
• Gearbox status (JATCO derivatives only) - LCD
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Instrument pack
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Freelander 2001 MY
The instrument pack also features a number of warning lamps. The warning lamps illuminate in
one of four colours which indicate the level of importance of the warning as follows:
• Red = Warning
• Yellow = Caution
• Green = System operative
• Blue = Headlamp main beam operative
The warning lamps are located in various positions around the periphery of the analogue gauges
in the instrument pack display and in the lower half of the tachometer. The direction indicators and
main beam warning lamps are located at the top of the display.
The following warning lamps are available:
• Left and right hand indicators (Green)
• Headlamp main beam (Blue)
• Glow plug (Yellow) - Diesel models only
• Seat belt (Red) - Selective markets only
• SRS (Red)
• Engine Malfunction Indicator Lamp (MIL) (Yellow) - All markets except NAS
• Service Engine Soon (MIL) (Yellow) – NAS only
• Anti-lock Braking system (ABS) (Yellow)
• Door open (Red)
• Hazard warning (Red)
• Hill descent control information (Green)
• Hill descent control fault (Yellow)
• Handbrake and brake system (Red)
• Low oil pressure (Red)
• Ignition/No charge (Red)
• Engine malfunction (Yellow) - Diesel models only - All markets except NAS
• Service Engine (Engine malfunction) (Yellow) - NAS only
• Overspeed (Red) - Selective markets only
• Cruise control (Yellow) - JATCO models only
• Low fuel level (Yellow)
• Trailer lamp failure warning lamp
Operating Modes
The instrument pack will function in seven modes:
• Shut down
• Normal
• Standby normal
• Powered/Unpowered
• Diagnostic
• Crank
• Low battery voltage
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Instrument pack
Service Training
11-16-LR-W: Ver 1
Freelander 2001 MY
Shut down mode
The instrument pack enters shut down mode when the ignition is moved from position II to the off
position (0). Ignition voltage is removed and only the permanent battery feed is available. All CAN
gateway, diagnostic, instrument pack and warning lamp functions are suspended. Some
conventionally wired warning lamps can still function in shut down mode, i.e.; hazard warning
lamp.
When the instrument pack senses that the ignition supply has been removed, it can remain in
normal mode for up to fifteen seconds to allow the microprocessor to power down. In shut down
mode the total current draw for the instrument pack does not exceed 1mA.
Normal mode
The instrument pack enters normal mode when battery voltage from ignition switch position II is
received. The ECM transmits a message for the CAN standard. If this message is correct or not
received, the instrument pack remains in normal mode. If an incorrect CAN standard message is
received, the instrument pack will enter standby normal mode.
Standby normal mode
Standby normal mode is used if an incorrect CAN standard message is received and also allows
access to diagnostics. In this mode all CAN transmissions are terminated and the pack will not
respond to any CAN messages received. All conventionally wired warning lamps will function
normally and the pack can enter diagnostic mode if required. A fault flag is recorded in the
EEPROM for the CAN standard message fault.
Powered/unpowered modes
Powered mode is the standard operational condition for the instrument pack. In this condition the
pack receives a permanent 12V battery supply, no ignition supply or CAN messages. The
microprocessor is also ‘off’ but the real time clock will remain powered.
Unpowered mode is entered when the vehicle battery is disconnected. When the power supply is
restored, the pack will resume powered mode.
Diagnostic mode
To enter diagnostic mode, the instrument pack must first be in normal or standby normal mode
and TestBook or another diagnostic tool must be connected to the diagnostic socket. The
instrument pack will enter diagnostic mode when it receives a valid message on the ISO9141 K
Line. Confirmation of access to this mode is given by a 'dIAg' message in the LCD.
Diagnostic mode is exited by receipt of a message from the diagnostic tool to terminate
diagnostics. Removal of the ignition switch position II battery supply or disconnection of the
diagnostic communication to the socket will also terminate the diagnostic mode.
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Instrument pack
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Freelander 2001 MY
Crank mode
When the starter motor is cranking the engine, the current drain may cause the values of inputs
and CAN messages to become corrupted or invalid. The instrument pack senses that cranking is
operative when ignition switch positions II and III are active and the ignition feed from switch
position II falls to approximately 3V.
During cranking, all inputs to gauges are suspended and the gauges will remain in their pre-crank
state. The odometer display is not affected.
Low battery operation
If the permanent battery supply voltage falls to below 8V, CAN message transmissions will be
suspended and received CAN messages will be ignored, analogue gauges will read zero and
warning lamp operation is suspended. When the voltage rises above 8V, normal instrument pack
operation is resumed.
Speedometer
The speedometer is electronically operated and contains an LCD. Each model has a maximum
scale indication of 136 mph (220 km/h).
The speedometer is driven by CAN messages from the ABS ECU. The messages are generated
by an ABS wheel speed sensor which produces pulses as the reluctor rotates. The instrument
pack microprocessor processes the incoming CAN message from the ABS ECU and converts it
into electrical signals for speedometer operation. The message received from the ABS ECU is an
average of all four working wheel speed sensors.
If the CAN message fails for more than 64ms the microprocessor will terminate speedometer
operation and record a fault flag. The recorded fault can be accessed using TestBook.
Liquid crystal display (LCD)
The LCD shows odometer readings up to 99999.9 miles or kilometres and trip computer readings
up to 999.9 miles or kilometres. A trip counter reset button is located at the bottom of the
speedometer and resets the counter to zero when pressed for more than two seconds. A short
press will change the LCD display from odometer to trip.
On KV6 vehicles with JATCO automatic gearbox, the LCD also displays current gear selected. If
a fault occurs with the gearbox which causes the transmission into 4th gear default mode, the
display will alternatively flash 'F' and '4'.
Tachometer
The tachometer is electronically operated and is driven by CAN messages from the ECM. The
ECM output is derived from the crankshaft position (CKP) sensor. Loss of the CAN message will
cause the tachometer to read zero until the engine speed message is restored.
Petrol models have a maximum tachometer scale reading of 8000 rev/min and Diesel models
have a maximum scale reading of 6000 rev/min.
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Freelander 2001 MY
The tachometer scale has a red segment which denotes the maximum engine speed for the
model. The engine must not be operated beyond the start of the red segment. The maximum
engine speed for the models is as follows:
• Petrol models - 6500 rev/min
• Diesel models - 4500 rev/min
Three warning lamps are located in the lower part of the tachometer face; Cruise control,
Malfunction Indicator Lamp (MIL) and handbrake and brake warning lamp.
Fuel Level Gauge
The fuel level gauge pointer indicates the current fuel level in the fuel tank. The fuel level gauge
pointer returns to the empty position when the ignition is switched 'off'.
The gauge is operated by an output from the fuel gauge to the fuel tank sender which is integral
with the fuel pump. The sender is a float operated rotary potentiometer which provides a variable
resistance to earth for the output from the gauge. Movement of the sender unit float arm varies the
electrical resistance across the sender unit, so the voltage of the control signal and the resultant
deflection of the gauge pointer are directly related to the level of fuel in the tank. When the sender
float is at its lowest point, indicating an empty fuel tank, the resistance to earth is at its greatest.
The measured resistance is processed by the instrument pack to implement an anti-slosh function.
This monitors the signal and updates the fuel gauge pointer position at regular intervals. This
prevents constant needle movement caused by fuel movement in the tank due to cornering or
braking.
A warning lamp is located in the face of the fuel gauge and illuminates when the fuel level is at or
below 2.2 gallons (10 litres).
The fuel level sender signal is converted into a CAN message by the instrument pack as a direct
interpretation of the fuel tank contents in litres. The ECM uses the CAN message to suspend OBD
misfire detection when the fuel level is below 15% capacity.
Sender Unit Resistance, Ω(Ohms)
503
413
302
135
Nominal Gauge Reading
Empty
Low fuel level illumination
Half full
Full
Engine coolant temperature gauge
The coolant temperature gauge indicates the temperature of the engine coolant. When the engine
reaches normal operating temperature, the gauge rests at the mid-point of the temperature scale.
If the engine coolant temperature becomes too high, the pointer will rise to the red segment of the
scale to warn of an engine cooling fault. At this position the engine coolant temperature is too high
and continued operation could result in engine damage; the vehicle should be stopped as soon as
possible.
The engine coolant temperature gauge is driven by a CAN message from the ECM. The ECM
derives the engine coolant temperature from an engine coolant temperature (ECT) sensor.
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Instrument pack
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Freelander 2001 MY
The temperature gauge is fitted with a return magnet causing the gauge to return to zero when the
ignition is switched 'off'. The coolant temperature gauge is only operative when the ignition switch
is in position II or when diagnostics are selected.
When the engine is hot, the gauge will display normal temperature until the engine has been
running for more than 15 seconds. This prevents the gauge moving to the red sector of the gauge
if the ignition is turned 'off' and then 'on' after a journey. If the engine is not started, the coolant
pump will not circulate coolant and local hot spots occur in the engine and give an incorrect
temperature reading. The 15 second delay allows for the engine to be started and coolant
circulated, allowing the gauge to display the true average temperature.
Coolant temperature gauge needle position
Cold
Normal
Hot (Red zone)
Engine coolant temperature °C (°F)
40 (104)
75 - 115(167 - 239)
120 (248)
Instrument illumination
The instrument pack back lighting illumination is provided by three, T10 single filament 3.4W 14V
bulbs. The bulbs are rated at 14V to improve their resistance to failure and are fitted with a
coloured shroud to give the required back light illumination colour.
The lamps illuminate when the side lamps or headlamps are switched 'on' and are also controlled
by the instrument illumination dimmer control.
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Instrument pack
Service Training
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Freelander 2001 MY
Heating, ventilation and air conditioning
Heating, ventilation and air conditioning
Heating and ventilation
Figure 16
1.Control panel
2.Distribution ducts
3.Heater assembly
4.Connector hose
5.Air inlet duct
The heating and ventilation system controls the temperature and distribution of air supplied to the
vehicle interior. Air is drawn into a heater assembly through a connector hose and an air inlet duct,
or through the cooling unit on vehicles with air conditioning.
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Freelander 2001 MY
In the heater assembly, the air can be heated and supplied as required to fascia and floor level
outlets. An electrical variable speed blower, and/or ram effect when the vehicle is in forward
motion, forces the air through the system. Temperature, distribution and blower controls are
installed on a panel on the centre console.
The air inlet duct connects the passenger's side of the plenum to the heater assembly, to provide
the fresh air inlet. The upper end of the duct locates in a slot in the body and the lower end of the
duct is connected to the heater assembly via a corrugated connector hose. A pollen filter is
installed in the air inlet duct and retained by four scrivets.
The heater assembly heats and distributes air as directed by selections made on the control panel.
The assembly is installed on the vehicle centre-line, between the fascia and the engine bulkhead.
The heater assembly consists of a two-piece plastic casing containing a blower, resistor pack,
heater matrix and control flaps. Integral passages guide the air through the casing from the inlet
to the distribution outlets. A wiring harness connects the blower and resistor pack to the blower
switch on the control panel.
Four control flaps are installed in the heater assembly to control the temperature and distribution
of air. A blend flap controls the temperature by directing air inlet flow through or away from the
heater matrix. Two distribution flaps control the air flow distribution to the selected vents. The
fourth flap closes the air path from the off side of the heater matrix to the blend chamber. This
helps to reduce heat pick-up causing a rise in temperature at the foot and defrost outlets in
comparison to the temperature at the face vent outlets.
The blower switch and the resistor pack control the operation of the blower, which can be selected
to run at one of four speeds. The resistor pack supplies reduced voltages to the blower motor for
blower speeds 1, 2 and 3. For blower speed 4, the resistor pack is bypassed and battery voltage
drives the motor at full speed. The pack is installed in the RH side of the casing, in the air outlet
from the blower fan, so that any heat generated is dissipated by the air flow.
The heater matrix provides the heat source to warm the air being supplied to the distribution
outlets. It is installed in the LH side of the casing behind a protective cover. The matrix is a copper
and brass, two pass, fin and tube heat exchanger. Engine coolant is supplied to the matrix through
two brass tubes that extend through the bulkhead into the engine compartment. When the engine
is running, coolant is constantly circulated through the heater matrix by the engine coolant pump.
On diesel models, the coolant flow is assisted by an electric pump when the fuel burning heater
system is operating.
Heating and ventilation operation
Air flow through the heater assembly is directed to the outlets selected by the distribution control
knob. The temperature of the air from all except the face level vents depends on the setting of the
temperature control knob. Hot air is available from the face level vents only when the temperature
control knob is at the maximum heat setting. As the temperature control knob is turned towards
cold, the temperature of the air from the face level vents rapidly decreases to ambient (non A/C
vehicles) or evaporator outlet temperature (A/C vehicles). The forward speed of the vehicle and
the setting of the blower control knob determines the volume of air flowing through the system.
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Freelander 2001 MY
Air distribution
Turning the distribution knob on the control panel turns the control flaps in the heater assembly to
direct air to the corresponding fascia and footwell outlets.
Air temperature
Turning the temperature knob on the control panel turns the related blend flaps in the heater
assembly. The blend flaps vary the proportion of air going through the cold air bypass and the
heater matrix. The proportion varies, between full bypass/no heat and no bypass/full heat, to
correspond with the position of the temperature knob.
Blower speed
The blower can be selected 'off', or to run at one of four speeds. While the ignition is on and the
blower switch is set to positions 1, 2, 3 or 4, ignition power energises the blower relay, which
supplies battery power to the blower. At switch positions 1, 2 and 3, the blower switch also
connects the blower to different earth paths through the resistor pack, to produce corresponding
differences of blower operating voltage and speed. At position 4, the blower switch connects an
earth direct to the blower, bypassing the resistor pack, and full battery voltage drives the blower
at maximum speed.
Fresh/Recirculated inlet air
When the recirculated air switch is latched in, the indicator LED in the switch illuminates and an
earth is connected to the recirculated air side of the fresh/recirculated air servo motor. The fresh/
recirculated air servo motor then turns the control flaps in the air inlet duct to close the fresh air
inlet and open the recirculated air inlets.
When the latch of the recirculated air switch is released, the indicator LED in the switch
extinguishes and the earth is switched from the recirculated air side to the fresh air side of the
fresh/recirculated air servo motor. The fresh/recirculated air servo motor then turns the control
flaps in the air inlet duct to open the fresh air inlet and close the recirculated air inlet.
Air conditioning
Where fitted, the air conditioning system supplies cooled and dehumidified, fresh or recirculated
air to the interior of the vehicle. Air is cooled by drawing it through the matrix of an evaporator. The
air is then ducted into the heater assembly, from where it is distributed to the vehicle interior
through the heating and ventilation system air ducts.
In the heater assembly, the temperature of the air distributed to the vehicle interior can be adjusted
by passing a proportion, or all, of the cooled air through the heater matrix. The volume of air being
distributed is controlled by the variable speed blower in the heater assembly. For details of
temperature control and distribution.
The air conditioning system uses a pressure sensor and evaporator temperature sensor to provide
operating condition feedback to the engine management system to enable the ECM to predict
engine load and run the cooling fans in response to changing atmospheric conditions and driver
demand.
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Heating, ventilation and air conditioning
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Freelander 2001 MY
Refrigerant system
The refrigerant system is a sealed closed loop system which is charged with Refrigerant R134a
as the heat transfer medium. It works in combination with a blower unit, blend unit and control
system to achieve the desired air temperature. ND-8 oil is added to the refrigerant to lubricate the
internal components of the compressor. The refrigerant system comprises of the following main
components connected together by refrigerant lines:
• Compressor (variable load)
• Condenser (with modulator)
• Thermostatic expansion valve
• Evaporator
To accomplish the transfer of heat, the refrigerant is circulated around the system, where it passes
through two pressure/temperature regimes. In each of the pressure/temperature regimes, the
refrigerant changes state, during which process maximum heat absorbtion or release occurs. The
low pressure/temperature regime is from the thermostatic expansion valve, through the
evaporator to the compressor; the refrigerant decreases in pressure and temperature at the
thermostatic expansion valve, then changes state from liquid to vapour in the evaporator, to
absorb the heat. The high pressure/temperature regime is from the compressor, through the
condenser and modulator (receiver/drier), back into the condenser where it is supercooled and
then to the thermostatic expansion valve. The refrigerant increases in pressure and temperature
as it passes through the compressor, then releases heat and changes state from vapour to liquid
in the condenser.
Fan blown air is passed through the evaporator where it is cooled by absorption due to the low
temperature refrigerant in the evaporator. Most of the moisture held in the air is condensed into
water by the evaporator and drains away beneath the vehicle via a drain tube.
The compressor receives the returned low pressure, warm, vaporised refrigerant from the
evaporator to complete the refrigeration cycle.
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Freelander 2001 MY
Refrigerant flow
Figure 17
1.Compressor
2.Condenser
3.Receiver drier (integral to the condenser)
4.Thermostatic expansion valve
5.Evaporiser
The compressor (1) compresses the refrigerant, which is in gas/vapour form at this stage and, in
doing so, increases the refrigerant temperature and pressure. The refrigerant flows into the
condenser (2) located at the front of the vehicle, in front of the coolant radiator. The cooling effect
of the air flow condenses the refrigerant into a liquid form which then flows to the receiver/drier (3),
still at high pressure. The receiver/drier acts as a refrigerant storage tank, absorbs moisture/water
and filters out any particles in the refrigerant. From here, the liquid refrigerant flows back through
the lower portion of the condenser to further cool the liquid refrigerant (sub-cooling). The
refrigerant then flows into the thermostatic expansion valve (4) which controls the amount of
refrigerant entering the evaporator (5) and lowers its pressure allowing it to expand. The pressure
drop rapidly reduces the temperature of the refrigerant. The heat from the air flowing into the
vehicle interior is much warmer and heat transfers from the air to the refrigerant cooling the air and
warming the refrigerant. The refrigerant changes back into gas/vapour and is sucked back into the
compressor for the cycle to begin again.
Only gas must be drawn into the compressor or it can cause hydrostatic lock and stall.
When operating, the top of the condenser will normally be full of warm/hot gas and the bottom full
of warm liquid refrigerant.
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Freelander 2001 MY
The refrigerant boiling point is very low (approx–30°C at atmospheric pressure) but can be
compressed back to liquid form by increasing the pressure at which it is contained. Compression
of the refrigerant produces heat, and this heat is removed by the condenser located at the front of
the vehicle.
Compressor
A variable displacement compressor is driven from the crankshaft via the ancillary drive belt. An
electro-mechanical clutch is used to engage and disengage the drive between the drive belt pulley
and the compressor. Operation of the compressor clutch is controlled by the Engine Control
Module (ECM).
Power to the A/C compressor clutch is via the normally open contacts of an associated A/C
compressor clutch relay which is located in the engine compartment fusebox. When the coil of the
relay is grounded by the ECM, the relay contacts close and the clutch is powered to engage the
compressor to the drive belt pulley.
When the compressor is operational, pressurised refrigerant is circulated through the system. The
compressor pressurises low pressure, warm, vaporised refrigerant which it receives from the
evaporator, causing the refrigerant vapour to become very hot. The high pressure vaporised
refrigerant is passed from the compressor to the condenser mounted in front of the radiator. The
refrigerant increases in pressure and temperature as it passes through the compressor, then
releases heat and changes state from vapour to liquid in the condenser.
The compressor is attached to a mounting bracket on the engine, and is a seven cylinder wobble
plate unit with variable displacement. Operation of an electrically actuated clutch is controlled by
the Engine Control Module(ECM).
The compressor consists of a housing which contains a shaft mounted in radial and thrust
bearings. A lug plate is pressed onto the shaft and the clutch and pulley assembly is splined to the
end of the shaft at the front of the housing. A wobble plate is installed on the shaft and connected
to the lug plate by two guide pins. The wobble plate is a sliding fit on the shaft and biased away
from the lug plate by a spring. The outer circumference of the wobble plate is engaged in the ends
of seven pistons, which are located in cylinders equally spaced around the housing interior. Two
pressure chambers in the rear of the housing are connected to inlet and outlet ports in the housing
wall. Suction and discharge valves, between each cylinder and the chambers, control the flow of
vapour into and out of the cylinders. A control valve assembly regulates a servo (control) pressure
supplied through drillings in the housing of the chamber containing the wobble plate.
The control valve assembly consists of a ball valve operated by a push rod connected to a
diaphragm. Spring and atmospheric pressure on one side of the diaphragm are opposed by inlet
pressure on the opposite side of the diaphragm, and also by outlet pressure and a spring acting
on the ball valve. The ball valve controls a flow of vapour from the outlet pressure chamber to
produce the servo pressure in the wobble plate chamber.
When the engine is running and A/C is off, the clutch is de-energised and the compressor pulley
freewheels under the influence of the drive belt. Vapour pressures are equalised throughout the
compressor. The spring between the lug plate and the wobble plate holds the wobble plate at the
minimum tilt angle (to minimise load during system start-up).
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When A/C is requested, the electro-magnetic clutch is engaged and the pulley turns the central
shaft of the compressor. The lug plate and the wobble plate turn with the shaft, and the movement
of the angled wobble plate produces reciprocating movement of the pistons. Vapour from the inlet
pressure chamber is drawn into the cylinders, compressed, and discharged into the outlet
pressure chamber, producing a flow around the refrigerant circuit.
The flow rate through the compressor is determined by the length of the piston stroke, which is
controlled by the tilt angle of the wobble plate. The tilt angle of the wobble plate is set by the servo
pressure and compressor inlet pressure acting on the pistons during their induction stroke. A
relative increase of inlet pressure over servo pressure moves the pistons along their cylinders to
increase the wobble plate tilt angle, the piston stroke and the refrigerant flow rate.
The control valve regulates the servo pressure in the wobble plate chamber as a function of inlet
pressure, so that the flow rate of the compressor matches the thermal load at the evaporator, i.e.
the more cooling effort that is required in the cabin of the vehicle, corresponds to a higher thermal
load and flow rate. Servo pressure varies between inlet pressure and inlet pressure + 1 bar (14.5
lbf.in2).
On start-up, the compressor inlet pressure is relatively low. In the control valve, the diaphragm and
push rod hold the ball valve open. This allows a restricted flow of outlet pressure through the ball
valve into the wobble plate chamber, which maintains the wobble plate at a low tilt angle. As the
refrigerant flows through the evaporator and absorbs heat (i.e. as the thermal load increases) the
pressure of the vapour entering the compressor increases. In the control valve, the increased inlet
pressure causes the diaphragm and push rod to move to close the ball valve. The resultant
reduction in wobble plate chamber pressure, together with the increase in inlet pressure, causes
pistons on their induction stroke to move the wobble plate to a higher tilt angle and increase the
piston stroke and the refrigerant flow through the compressor. When the thermal load of the
evaporator decreases, the subsequent decrease in pressure of vapour entering the compressor
causes the control valve to open. This increases the wobble plate chamber pressure, which in turn
reduces the tilt angle of the wobble plate and the refrigerant flow through the compressor.
By matching the refrigerant flow to the thermal load of the evaporator, the variable compressor
maintains a relatively constant evaporator temperature of approximately 3 to 4 °C (37 to 39°F).
Air Conditioning Control System
In conjunction with the Engine Control Module (ECM), the air conditioning control system operates
the cooling/condenser fans and the compressor clutch to control the flow of refrigerant through the
system.
The air conditioning control system comprises of a compressor clutch relay, an evaporator
temperature sensor, a refrigerant pressure sensor, a cooling fan control module and control
switches. These controls, in conjunction with the cooling fans, compressor clutch, blower and
heater distribution and blend unit, maintain the required environment inside the vehicle with
minimal input from the driver.
When air conditioning is not selected, air is supplied by ram effect or blower operation to the areas
selected by the air distribution control. The air mix flap on the heater assembly blend unit controls
the temperature of the air being delivered. No cooled air is available.
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Freelander 2001 MY
Selecting air conditioning provides the added facility of cooled air available to be mixed with
heated air in the blend unit. When required, a fully cold condition can be selected by turning the
temperature control selector to the cold position, this automatically closes the path of inlet air
through the heater matrix.
Mixtures of cooled, fresh, and hot air can be selected to give the required interior environmental
conditions by selection at the control panel.
Compressor clutch relay
The compressor clutch relay switches power to the compressor clutch under the control of the
ECM. The relay is located in the engine compartment fusebox. The compressor clutch is
energized to engage and de-energized to disengage.
Compressor
Operation of the clutch is controlled by the engine control module (ECM). To protect the refrigerant
system from unacceptably high pressure, a pressure relief valve is installed in the outlet side of
the compressor. The pressure relief valve is set to operate at 3430 kPa (497.5 lbf.in) and vents
excess pressure into the engine compartment.
The ECM controls the operation of the compressor via the compressor clutch relay in the engine
compartment fuse box. When the A/C switch is used to request air conditioning, the ECM
energises the compressor clutch relay to supply a power feed to the compressor clutch.
Engagement of the compressor clutch is withheld, or discontinued, if refrigerant pressure exceeds
upper or lower pressure limits:
• The upper pressure limit is 29 bar (421 lbf/in2), e.g. due to a blockage. Compressor
engagement is re-enabled when the pressure decreases to 23 bar (334 lbf.in2).
• The lower pressure limit is 1.6 bar (23.2 lbf/in2), e.g. due to a leak. Compressor engagement
is re-enabled when the pressure increases to 2.0 bar (29.0 lbf/in2).
Refrigerant pressure sensor
The refrigerant pressure sensor is located in the refrigerant lines. On LHD vehicles with KV6
engines it is located at the RH side of the engine compartment close to the outlet from the
condenser in the refrigerant line leading to the thermostatic expansion valve. On all other engine/
vehicle derivatives the sensor is located in the same refrigerant line at the LH side of the engine
compartment. The refrigerant pressure sensor provides the ECM with a pressure input from the
high pressure side of the refrigerant system.
The ECM uses the signal from the refrigerant pressure sensor to protect the system from extremes
of pressure, by disengaging the compressor clutch. The signal is also used for cooling fan control.
The temperature sensor used has a low pressure range of 0 – 600 psi and provides the following
functions:
• Provide a safety cut-out function if the refrigerant pressure goes either too high or too low
• Indicate when the refrigerant pressure reaches such a point that additional cooling is required
– if the pressure reaches the medium point, the cooling fans will be switched to high speed
• The pressure sensor is used in conjunction with the evaporator temperature sensor to predict
compressor load for load management at idle/part throttle
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On petrol engine vehicles, the pressure sensor signal is fed directly to the ECM. On diesel model
vehicles, the pressure sensor is connected to the Instrument Pack, and the signal is relayed to the
ECM from the Instrument Pack via the CAN Bus.
Because the compressor is lubricated by oil suspended in the refrigerant, a low pressure signal
from the sensor is used by the ECM to prevent operation of the compressor unless there is a
minimum refrigerant pressure, and thus refrigerant and oil in the system.
Evaporator temperature sensor
The evaporator temperature sensor is an encapsulated thermistor with a negative temperature
coefficient (NTC) that provides the ECM with an input of the evaporator air outlet temperature. The
sensor is connected to the ECM to provide it with a temperature signal, so that it can prevent the
air conditioning system from operating when the evaporator is frozen. Frosting of the evaporator
cooling fins will cause a reduction in the effectiveness of the cooling system.
If the temperature at the evaporator falls low enough for ice to form on the fins, the ECM withholds
or discontinues engagement of the compressor clutch. When the temperature at the evaporator
rises sufficiently, the ECM engages the compressor clutch.
The evaporator temperature sensor is also used in conjunction with the refrigerant pressure
sensor to facilitate compressor load prediction for optimum idle speed control and load
management. The A/C system places an extra load on the engine when the compressor is
operating, so the ECM automatically adjusts the idle speed to compensate for the additional load.
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Air conditioning operation
Air conditioning operates only while the engine is running and the blower in the heater assembly
is on (any speed). Fresh or recirculated air can be selected with or without the air conditioning
being on, provided the ignition is ‘ON’.
When the air conditioning switch is selected ‘ON’, the indicator lamp in the switch illuminates and
an air conditioning request signal is input to the ECM via the Instrument pack and CAN Bus. The
air conditioning request signal consists of a positive voltage supply via the blower switch and A/C
switch, hard wired to the instrument pack. The instrument pack interprets the A/C request signal
and informs the ECM of the condition using a message on the CAN Bus. The ECM is also in
receipt of signals from the refrigerant pressure sensor and the evaporator temperature sensor,
which it uses to determine the necessary cooling fan speed and compressor clutch control.
On receipt of the air conditioning request signal, the ECM switches air conditioning on by signalling
the compressor clutch relay module to engage the compressor clutch and the cooling fan
controller to run the cooling fans at the appropriate speed using a PWM signal. The engine drives
the compressor to circulate the refrigerant. The blower draws fresh or recirculated air through the
evaporator. As the air flows through the evaporator, moisture condenses out from the relatively
warm air onto the cold evaporator. The dehumidified air is then fed into the heater assembly, from
where it is distributed to the vehicle interior.
When the air conditioning switch is selected ‘OFF’, or if the blower is selected ‘OFF’ the indicator
lamp in the air conditioning switch extinguishes and the air conditioning request signal is removed
from the ECM. The ECM then switches air conditioning off by signalling the relay module to
disengage the compressor clutch and cooling fan controller to terminate the operation of the
cooling fans.
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Fuel burning heater
Fuel burning heater fuel pump
The fuel burning heater (FBH) regulates the fuel supply to the FBH unit. The FBH fuel pump is
installed in a rubber mounting attached to the underside of the chassis near the rear RH
wheelarch. The pump is a self priming, solenoid operated plunger pump, with a fixed displacement
of 0.063 cm3 / Hz (0.002 US fl.oz / Hz). The ECU in the FBH unit outputs a pulse width modulated
signal to control the operation of the pump. When the pump is de-energised, it provides a positive
shut-off of the fuel supply to the FBH unit.
FBH fuel pump nominal operating speeds/outputs
Operating phase
Start sequence
Part load
Full load
Speed, Hz
0.70
1.35
2.70
Output, l/h (US galls/h)
0.159 (0.042)
0.306 (0.081)
0.612 (0.163)
The solenoid coil of the FBH fuel pump is installed around a housing which contains a plunger and
piston. The piston locates in a bush, and a spring is installed on the piston between the bush and
the plunger. A filter insert and a fuel line connector are installed in the inlet end of the housing. A
non-return valve and a fuel line connector are installed in the fuel outlet end of the housing.
While the solenoid coil is de-energised, the spring holds the piston and plunger in the 'closed'
position at the inlet end of the housing. An 'O' ring seal on the plunger provides a fuel tight seal
between the plunger and the filter insert, preventing any flow through the pump. When the
solenoid coil is energised, the piston and plunger move towards the outlet end of the housing, until
the plunger contacts the bush. In this condition, fuel is drawn through the inlet connection and
filter. The initial movement of the piston also closes transverse drillings in the bush and isolates
the pumping chamber at the outlet end of the housing. Subsequent movement of the piston then
forces fuel from the pumping chamber through the non-return valve and into the line to the FBH
unit. When the solenoid coil de-energises, the spring moves the piston and plunger back towards
the closed position. As the piston and plunger move towards the closed position, fuel flows past
the plunger and through the annular gaps and transverse holes in the bush to replenish the
pumping chamber.
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Fuel Burning Heater (FBH) Unit
Figure 18
1.Combustion air fan
2.Electronic board
3.Heat exchanger
4.Stainless steel burner
5.Fuel supply
6.Glowpin/Flame detector
7.Evaporiser
8.Water pump
The FBH unit is located at the LH side of the engine compartment, behind the front of the LH
wheelarch. The unit is connected in series with the coolant supply to the heater assembly. Two
electrical connectors on the top of the FBH unit connect to the vehicle wiring.
The fuel burning heater unit consists of:
• A circulation pump
• A combustion air fan
• A burner housing
• An ECU/heat exchanger
• An air inlet hose
• An exhaust pipe
Circulation pump
The pump runs continuously while the FBH unit is in standby or active operating modes. While the
FBH unit is inactive, coolant flow is reliant on the engine coolant pump.
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Combustion air fan
The combustion air fan regulates the flow of air into the unit to support combustion of the fuel
supplied by the FBH pump. It also supplies the air required to purge and cool the FBH unit.
Ambient air is supplied to the combustion air fan through an air inlet hose containing a sound
deadening foam ring.
Burner housing
The burner housing contains the burner insert and also incorporates connections for the exhaust
pipe, the coolant inlet from the circulation pump and the coolant outlet to the heater assembly. The
exhaust pipe directs exhaust combustion gases to atmosphere at the bottom of the engine
compartment.
The burner insert incorporates the fuel combustion chamber, an evaporator and a glow plug/flame
sensor. Fuel from the FBH fuel pump is supplied to the evaporator, where it evaporates and enters
the combustion chamber to mix with air from the combustion air fan. The glow plug/flame sensor
provides the ignition source of the fuel/air mixture and, once combustion is established, monitors
the flame.
ECU/Heat exchanger
The ECU controls and monitors operation of the FBH system. Ventilation of the ECU is provided
by an internal flow of air from the combustion air fan. The heat exchanger transfers heat generated
by combustion to the coolant. A sensor in the heat exchanger provides the ECU with an input of
heat exchanger casing temperature, which the ECU relates to coolant temperature and uses to
control system operation. The temperature settings in the ECU are calibrated to compensate for
the difference between coolant temperature and the heat exchanger casing temperature detected
by the sensor. Typically: as the coolant temperature increases, the coolant will be approximately
7 °C (12.6 ° F) hotter than the temperature detected by the sensor.
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K series 1.8 petrol engine
K 1.8
Introduction
The well proven K series 16 valve 1.8 litre engine has undergone changes to meet new quality
and legislative standards. Specific enhancement include:
• EU3 emissions compliance
• New generation engine management system (MEMS 3) including full on-board diagnostics of
emission control equipment
• New camshaft drive belt auto-tensioners to reduce noise and increase service life from
60,000 to 90,000 miles
• New camshaft sensor - required by MEMS 3 for sequential fuelling
• New camshaft and timing belt covers with higher content of recyclable material and the
camshaft cover now facilitates the camshaft sensor
• New ignition system including plug top coils and coil covers
• New single supplier (Bosch) of electrical ancillaries
• Pre-catalytic converter fitted to the exhaust manifold down pipe
• Modified cylinder head assembly to allow for the camshaft sensor
• The alternator heat shield now covers the exhaust manifold
• The alternator/air conditioning belt now has an automatic tensioner
• Recyclable material for the camshaft timing and auxiliary belts
• The flow rate of the injectors have changed to meet emission targets
General
The K Series engine is built up from aluminium castings bolted together. These consist of three
major castings; the cylinder head, cylinder block and a bearing ladder, which is line bored to
provide the main bearing bores. Attached to these are three minor castings; above the cylinder
head, the camshaft carrier and the camshaft cover. Below the bearing ladder is an oil rail.
Each of the ten cylinder head bolts passes through the cylinder head, cylinder block and bearing
ladder to screw into the oil rail. This puts the cylinder head, cylinder block and bearing ladder into
compression with all the tensile loads being carried by the cylinder head bolts.
When the cylinder head bolts are removed; additional fixings are used to retain the bearing ladder
to the cylinder block and the oil rail to the bearing ladder.
The cross flow cylinder head is based on a four valve, central spark plug, combustion chamber
with the inlet ports designed to induce swirl and control the speed of the induction charge. This
serves to improve combustion and hence fuel economy, performance and exhaust emissions. The
twin overhead camshafts operate the valves via hydraulic tappets, one camshaft operates the
exhaust valves while the other operates the inlet valves. The camshafts are driven from the
crankshaft by a timing belt, belt tension being maintained by an automatic tensioner. The
camshafts are retained by the camshaft carrier, which is line bored with the cylinder head.
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Timing belt components
Figure 19
1.Upper front cover - timing belt
2.Seal - upper cover
3.Lower cover - timing belt
4.Seal - lower cover
5.Crankshaft pulley
6.Special washer - pulley bolt
7.Crankshaft pulley bolt
8.Camshaft timing belt
9.Camshaft timing gears
10.Tensioner
11.Index wire
12.Pointer
13.Crankshaft timing gear
14.Rear cover
When installing the new type belt tensioner, ensure that the index wire is positioned over the pillar
bolt and that the tensioner lever is at the 9 o'clock position.
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Freelander 2001 MY
Timing belt tensioner
Figure 20
1.Automatic tensioner
2.Index wire
3.Pillar bolt
4.Securing bolt
5.Tensioner lever
Fit a new tensioner securing bolt and tighten until it is just possible to move the tensioner lever
then install the timing belt.
Using a 6 mm Allen key, rotate the tensioner anti-clockwise and align the centre of the indent on
the tensioner pointer to the index wire. Ensure that the pointer approaches the index wire from
above.
Tensioner adjustment
Figure 21
1.6 mm Allen key
2.Tensioner
3.Index wire
4.Pointer indent
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NOTE:For the full procedure of this process refer to the workshop manual.
The plug-top coil ignition system utilises a camshaft sensor located in the camshaft carrier,
adjacent to the exhaust camshaft. The camshafts have an integral reluctor ring, which provides an
input to the camshaft sensor. Twin coils are fitted on top of the camshaft cover, each coil supplying
HT voltage to one pair of spark plugs.
Plug-top coil
Figure 22
1.Multiplug
2.HT lead
3.Coil
4.harness
Self-adjusting hydraulic tappets are fitted on top of each valve and are operated directly by the
camshafts. The valve stem oil seals are moulded onto a metal base which also act as the valve
spring seat on the cylinder head.
Exhaust valves are of the carbon break-type. A machined profile on the valve stem removes any
build up of carbon in the combustion chamber end of the valve guide thereby preventing valves
from sticking.
The stainless steel cylinder head gasket has moulded seals around all coolant, breather and oil
apertures and has steel cylinder bore eyelets. Limiters at each end of the gasket control
compression of the gasket.
The cylinder block is fitted with 'damp' cylinder liners, the bottom, stepped half of the damp liner,
being a sliding fit into the lower part of the cylinder block. The liners are sealed in the block with a
bead of Hylomar. The bead is applied around the stepped portion of the liner. The cylinder head
gasket effects the seal at the cylinder head with the liner top acting as a break between the
combustion chamber and gasket.
The aluminium alloy, thermal expansion pistons have a semi- floating gudgeon pin, which is offset
towards the thrust side and has interference fit in the small end of the connecting rod. Pistons and
cylinder liners are supplied in two grades. Big-end bearing diametric clearance is controlled by
three grades of selective shell bearing.
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The five bearing, eight balance weight crankshaft has its end-float controlled by thrust washer
halves at the top of the central main bearing. Bearing diametric clearance is controlled by three
grades of selective shell bearing. Oil grooves are provided in the upper halves of main bearings
No. 2, 3 and 4 to supply oil, via drillings in the crankshaft, to the connecting rod big-end bearings.
Manifolds and exhaust system
The following section covers the inlet manifold, exhaust manifold and exhaust system.
Inlet Manifold
Figure 23
1.Inlet manifold
2.Gasket
3.Screw
4.Nut (6 off)
5.Stud (6 off)
The inlet manifold is a one piece plastic moulding which is attached to the cylinder head on six
locating studs and nuts and further retained by oner bolt. A rubber moulded gasket, which is
located in a corresponding recess in the inlet manifold mounting face, seals the manifold to the
cylinder head.
The inlet manifold has vacuum take-off points for the fuel pressure accumulator, the brake servo
and the purge valve. A further take-off point vents the camshaft cover into the inlet manifold.
Two threaded lugs on the inlet manifold provide for the attachment of the fuel rail. Four ports at
the base of each inlet tract house the injectors which are sealed to the manifold with O-ring seals
and retained in position by the fuel rail.
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The Idle Air Control (IAC) valve is attached to the inlet manifold, adjacent to the throttle housing
and is secured with four Torx bolts and sealed to the manifold with an O-ring seal.
The throttle housing is attached to the left hand end of the inlet manifold and is secured with four
bolts and sealed with an O-ring seal. The Intake Air Temperature (IAT) sensor is mounted in No.
4 inlet tract.
Exhaust Manifold
Figure 24
1.Gasket
2.Exhaust manifold
3.Nut (5 off)
4.Heat shield
5.Spacer
6.Screw (2 off)
7.Nut
The exhaust manifold is a fabricated and welded steel construction. The four branch manifold is
located on five studs in the cylinder head and secured with five nuts. A metal corrugated gasket
seals the exhaust manifold to the cylinder head. The four separate branches of the manifold merge
into one at a starter catalytic converter. The starter catalytic converter is fitted with a flange which
mates with the exhaust system front pipe and is sealed with a metal gasket. Two captive studs in
the manifold pass through the mating flange of the front pipe and are secured with nuts.
A threaded boss above the starter catalytic converter allows for the fitment of a pre-catalyst
Heated Oxygen Sensor (HO2S). The HO2S measures the oxygen content of the exhaust gases
before they enter the starter catalyst.
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Exhaust System
The exhaust system comprises of a front pipe assembly incorporating a catalytic converter,
intermediate pipe assembly and a tailpipe assembly.
Figure 25
1.Mounting rubber (3 off)
2.Tail pipe assembly
3.Clamp
4.Gasket
5.Catalytic converter
6.Front pipe assembly
7.Heat shield
8.Nut (2 off)
9.Intermediate pipe assembly
10.Nut (2 off)
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Technical data
The table titled 'Technical data' displays technical information regarding the K series 1.8 16 valve
petrol engine.
Technical data
Description
Type
Capacity
Compression ratio
Firing order
Valve operation
Ignition system
Emission standard
Power
Torque
Lubrication system
Fuel system
Cooling system
Clutch
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Data
16 valve DOHC
1796 cm3
10.5:1
1-3-4-2
Self-adjusting hydraulic tappets
MEMS 3
ECD3 (EU3)
118 PS @ 5550 rpm
165 Nm @ 2750 rpm
Cast aluminum wet sump; crankshaft driven eccentric rotor oil pump
Returnless multipoint fuel injection, electronically controlled with electromechanical fuel injectors.
By-pass type also cooling the intermediate reduction drive
Maintinance free hydraulic system
K 1.8
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Freelander 2001 MY
Modular engine management system version 3
MEMS 3
General
The Modular Engine Management System Version 3 (MEMS 3) is a sequential, multiport fuel
injection system controlled by the Engine Control Module (ECM).
The ECM controls the operation of the fuel system, ignition system, evaporative emission control,
cooling system and air conditioning operation.
The ECM uses the speed/density method of air flow measurement to calculate fuel delivery. This
method calculates the density of the intake air by measuring its pressure and temperature.
The density signal, combined with the engine speed signal, allows the ECM to make a calculation
of the air volume being inducted and determine the quantity of fuel to be injected to give the correct
air/fuel ratio.
MEMS 3 is designed to meet new exhaust emission standard; ECD 3 (European Commission
Directive Stage 3), also known as OBD (On-Board Diagnostics).
Engine control module
Figure 26
The ECM is located in the environmental box (E-box) on the left hand side of the engine
compartment. The ECM is accessible by loosening five cap screws to release the lid on the box.
The ECM electronic components are housed in an aluminium case for heat dissipation and
protection from electro-magnetic interference.
With the ignition off, the ECM is supplied with permanent battery voltage to power the memory.
The voltage is supplied from the battery positive terminal via the engine compartment fusebox
fusible link 1 and fuse 5 to the ECM.
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When the ignition switch is in position II (ignition ‘ON’), the ECM receives battery voltage, via the
engine compartment fusebox fusible link 3 and the passenger compartment fusebox fuse 6, to the
ECM. The ECM energises the main relay by completing the earth path for the relay coil, which is
connected to the ECM. The main relay provides battery voltage to various peripheral components
and also to the ECM.
When the ignition switch is turned to position II, the ECM primes the fuel system by running the
fuel pump for approximately two seconds. This is achieved by completing the earth path for the
fuel pump relay coil. The fuel pump relay coil is connected to battery voltage from the main relay,
the earth being supplied by the ECM. The ECM references the sensors and the IAC valve stepper
motor prior to start-up.
Security code information is exchanged between the ECM and the immobilisation ECU.
When the ignition switch is turned to position III (crank), the ECM communicates with the
immobilisation ECU. If it receives authority to start, the ECM begins ignition and fuelling when CKP
and CMP sensor signals are detected. The ECM will run the fuel pump continuously when CKP
sensor signals are received (crank turning).
When the ignition switch is turned to position 0 (‘OFF’), the ECM switches ‘OFF’ ignition and
fuelling to stop the engine. The ECM continues to hold the main relay in the on position until it has
completed the power down functions. Power down functions include engine cooling and
referencing the IAC valve stepper motor and includes memorising data required for the next start
up. When the power down process is completed, the ECM switches off the main relay and enters
a low power mode. During low power mode the ECM will consume less than 1mA.
If the ECM suffers an internal failure, such as a break down of the processor or driver circuits, there
are no back up systems or limp home capability. If a sensor circuit fails to supply an input, this will
result in a substitute or default value being adopted where possible. This enables the vehicle to
function, but with reduced performance.
Heated oxygen sensor
Heated Oxygen sensor
Figure 27
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Two HO2S are used on the MEMS 3 system to comply with the requirements of ECD 3. A precatalyst HO2S is located in the exhaust manifold, upstream of the starter catalyst and a post
catalyst HO2S is located in the exhaust system, downstream of the main catalyst. The sensors
provide feedback signals to the ECM which enable it to control the Air/Fuel Ratio (AFR). The
principal purpose of the sensors is to enable tight control of AFR around the 14.7:1 AFR (by
weight) which produces the best composition of exhaust gas for peak catalyst conversion
efficiency.
The upstream (pre-catalyst) sensor is the main sensor used for closed loop fuelling. The
downstream (post-catalyst) sensor is used to monitor the performance of the main catalyst and to
trim the fuelling provided by the pre-catalyst sensor.
If an HO2S fails, the ECM adopts an open loop fuelling strategy to minimise emissions, stores fault
codes which can be retrieved using TestBook and, on vehicles manufactured after the EDC3
compliance date, illuminates the Malfunction Indicator Lamp (MIL) in the instrument pack.
The HO2S consists of a sensing element, the outer surface of which is exposed to exhaust gases,
while the inner surface is exposed to ambient air. The sensor has a ceramic coating to protect the
sensing element from contamination and heat damage.
Heated Oxygen sensor structure
Figure 28
a. Ambient air
b. Exhaust gases
1. Protective ceramic coating
2. Electrodes
3. Zirconium Oxide
The amount of oxygen in ambient air is constant at approximately 20%. The oxygen content of the
exhaust gases varies with the AFR with a typical value for exhaust gas of around 2%.
The difference in oxygen content of the two gases produces an electrical potential difference
across the sensing element. Rich mixtures, which burn almost all of the available oxygen, produce
high sensor voltages. During lean running, there is an excess of oxygen in the mixture and some
of this oxygen leaves the combustion chamber unburnt.
In these conditions, there is less difference between the oxygen content of the exhaust gas and
the ambient air, and a low potential difference (voltage) is output by the HO2S. The ECM uses the
voltage produced in the HO2S sensing element to calculate the AFR and thereby control fuelling
to a high degree of accuracy.
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The material used in the sensing element only becomes active at a temperature of 300°C (572°F),
therefore it is necessary to provide additional heating via an electrical resistive element. The
element uses a 12V supply from the main relay when the ECM energises the relay coil and allows
a short warm up time and minimises emissions from start-up. The resistance of the heating
element can be measured using a multimeter and should be 6Ω at 20°C (68°F).
Heating element resistance
Figure 29
a.
b.
c.
d.
Rich AFR
Lean AFR
Lambda window
HO2S Output in mV.
Crankshaft position sensor
Figure 30
The variable reluctance crankshaft position (CKP) sensor is mounted at the rear of the engine with
the sensor tip facing the engine face of the flywheel and is secured in the casting with a single
screw. The sensor tip of the CKP sensor is adjacent to a profiled target ring formed on the inner
face of the flywheel.
The signal produced by the CKP sensor allows the ECM to calculate the rotational speed and
angular position of the crankshaft. This information is required by the ECM to calculate ignition
timing, fuel injection timing and fuel quantity during all conditions when the engine is cranking or
running. If the CKP sensor signal is missing, the vehicle will not run as there is no substitute signal
or default.
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The CKP sensor is a variable reluctance sensor and provides an analogue voltage output, relative
to the speed and position of the target on the flywheel. A permanent magnet inside the sensor
applies a magnetic flux to a sensing coil winding. This creates an output voltage which is read by
the ECM.
As the gaps between the poles of the target pass the sensor tip, the magnetic flux is interrupted
and this causes a change to the output voltage.
Sensor targets
Figure 31
It is important to note that the ECM is unable to determine the exact position of the engine with its
four stroke cycle from the CKP sensor alone: the CMP sensor must also be referenced to provide
sufficient data for ignition control and sequential injection.
Camshaft sensor
Figure 32
The camshaft (CMP) sensor provides a signal which enables the ECM to determine the position
of the camshaft relative to the crankshaft. This allows the ECM to synchronise fuel injection for
start and run conditions. The CMP sensor provides an output to the ECM. The ECM provides an
earth for the sensor.
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The CMP sensor is located on the camshaft cover (under the plastic cover) at the opposite end to
the camshaft drive and reads off a reluctor on the exhaust camshaft.
The sensor is a hall effect sensor which detects the reluctor mounted on the exhaust camshaft.
The sensor receives a battery supply from the main relay. The sensor operates on the principle of
a voltage generated when the sensor is exposed to a magnetic flux. This causes a potential
difference in voltage as the reluctor passes the sensor which is detected as an digital signal by the
ECM.
The reluctor consists of a single 'tooth' design which extends over 180° of the camshaft's rotation,
for this reason it is known as a half moon cam wheel.
Camshaft reluctor
Figure 33
The half moon cam wheel reluctor enables the ECM to provide sequential fuel injection at start up,
but it cannot provide a back-up signal in cases of CKP sensor failure.
If the CMP sensor signal is missing, the engine will still start and run, but the fuel injection may be
out of phase. This will be noticeable by a reduction in performance and drivability, together with
an increase in fuel consumption and emissions.
As the camshaft rotates the signal will switch between the high and low voltages. The position of
the half moon cam wheel relative to the camshaft is not adjustable. The air gap between the CMP
sensor tip and the half moon cam wheel is not adjustable.
Manifold absolute pressure sensor
Figure 34
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The manifold absolute pressure (MAP) sensor is located on the forward face of the inlet manifold
and is secured with two Torx screws.
The output signal from the MAP sensor, together with the CKP and intake air temperature (IAT)
sensors, is used by the ECM to calculate the amount of air induced into the cylinders. This enables
the ECM to determine ignition timing and fuel injection duration values.
The MAP sensor receives a 5V ± 4% supply voltage from the ECM and provides an analogue
signal to the ECM, which relates to the absolute manifold pressure and allows the ECM to
calculate engine load. The ECM provides an earth for the sensor.
If the MAP signal is missing, the ECM will substitute a default manifold pressure reading based on
crankshaft speed and throttle angle. The engine will continue to run with reduced drivability and
increased emissions, although this may not be immediately apparent to the driver. The ECM will
store fault codes which can be retrieved using TestBook.
Engine coolant temperature sensor
Figure 35
The engine coolant temperature sensor (ECT) sensor is located in the cooling system outlet elbow
from the cylinder head and provides a signal which allows the engine temperature to be
determined. The ECM provides an earth for the sensor.
On vehicles with air conditioning, the A/C clutch will be disengaged if the engine temperature
reaches a predetermined level, and will not re-engage until it falls to a predetermined level.
The ECT sensor consists of an encapsulated Negative Temperature Coefficient (NTC) thermistor
which is in contact with the engine coolant. The ECM uses engine temperature to calculate fuelling
and ignition timing parameters during start up. It is also used to provide a temperature correction
for fuelling and ignition timing when the engine is warming up, running normally or overheating.
The ECT signal is used by the ECM to control the engine cooling fans.
If the ECT sensor fails or becomes disconnected, the ECM will use a default value which is based
on values from the engine oil temperature sensor. The driver may not notice that a fault is present
although a fault code will be stored in the ECM which can be retrieved using TestBook. The default
value will also include operation of the cooling fans in fast mode when the engine is running.
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Intake air temperature sensor
Figure 36
The intake air temperature (IAT) sensor is located in the intake manifold near cylinder number four
fuel injector. The sensor consists of an NTC thermistor mounted in an open housing to allow air
flow over the sensing element.
The IAT sensor provides a signal, which enables the ECM to adjust ignition timing and fuelling
quantity according to the intake air temperature, thus ensuring optimum performance, drivability
and low emissions. The ECM provides an earth for the sensor.
The IAT sensor is part of a voltage divider circuit which consists of a regulated 5 volt supply, and
a fixed resistor (both are inside the ECM) and a temperature dependent variable resistor (the IAT
sensor).
If the IAT sensor fails, or is disconnected, the vehicle will continue to run. The ECM will substitute
a default value using the information from the speed/load map to run the engine, but adaptive
fuelling will be disabled.
This condition would not be immediately apparent to the driver, but the ECM will store fault codes
which can be retrieved using TestBook.
Engine oil temperature sensor
Figure 37
The engine oil temperature sensor is located in the oil filter housing. The oil temperature measured
by the ECM is used to adjust fuelling values according to engine oil temperature.
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The use of an engine oil temperature sensor allows the ECM to provide optimum engine
performance and minimum emissions during the engine warm up phase. The ECM provides an
earth for the sensor.
The sensor consists of an encapsulated Negative Temperature Coefficient (NTC) thermistor
which is in contact with the engine oil.
If the sensor fails, the ECM will substitute a default value which is ramped up 90°C (194°F). This
condition will not be apparent to the driver.
The vehicle will run but may suffer from reduced engine performance and increased emissions as
adaptive fuelling is disabled. The ECM will store fault codes which can be retrieved using
TestBook.
Throttle position sensor
Figure 38
The throttle position sensor (TP) sensor is mounted on the throttle body and is driven from the end
of the throttle spindle. The TP sensor consists of a potentiometer which provides an analogue
voltage that the ECM converts to throttle position information.
The TP sensor signal is required for the following vehicle functions:
• Idle speed control
• Throttle damping
• Deceleration fuel cut off
• Engine load calculations
• Acceleration enrichment
• Full load enrichment
• Automatic gearbox shift points
The TP sensor is a potentiometer which acts as a voltage divider in an external ECM circuit. The
potentiometer consists of a 4kΩ ± 20% resistive track and a wiper arm, driven by the throttle
spindle, which sweeps over the track.
The track receives a regulated 5 V ± 4% supply from the ECM, together with an earth. As the wiper
arm moves over the track it will connect to areas of different voltage ranging from 0 to 5 volts. The
'output' from the wiper arm is connected to the ECM, to provide an analogue voltage signal.
The TP sensor requires no adjustment as the ECM will learn the lower voltage limit which
corresponds to closed throttle.
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If the TP sensor signal is missing the vehicle will continue to run but may suffer from poor idle
control and throttle response. The ECM will store fault codes which can be retrieved using
TestBook.
Idle air control valve (Bi-polar stepper motor)
Figure 39
The idle air control valve (IAC) valve is located on the inlet manifold. It allows the ECM to control
the engine idling speed by regulating the amount of air which by-passes the throttle valve. It also
allows the ECM to provide a damping function when the throttle is closed under deceleration which
reduces hydrocarbon (HC) emissions.
The IAC valve is controlled by the ECM using a stepper motor. This consists of a core which is
rotated by magnetic fields produced by two electro-magnet bobbins set at 90° to each other.
The stepper motor controls the volume of air passing through a duct which leads from the inlet
manifold to a pipe connected to the throttle body. The bobbins are connected to the ECM driver
circuits.
Each of the four connections can be connected to 12 volts or earth, enabling four 'phases' to be
obtained. The ECM drives the four phases, known as 'A', 'B', 'C' and 'D', to obtain the desired idle
speed.
When the ignition is switched ‘OFF’ the ECM enters a power down routine which includes
'referencing' the stepper motor. This means that the ECM will rotate the motor so that it can
memorise the position when it next needs to start the engine.
The stepper motor referencing procedure can take from three to five seconds. If the ECM cannot
reference the stepper motor during power down, it will do so at ignition on. If the stepper motor
fails, there are no back up idle control systems. The idle speed may be too high or too low and if
a load is placed on the engine it may stall. The ECM will store fault codes which can be retrieved
by TestBook.
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Ignition coils
Figure 40
Two ignition coils are mounted on the camshaft cover above the spark plugs for cylinders 1 and 3
and secured with screws.
Each coil operates a pair of spark plugs using the wasted spark principle. The coil has a plug
connection on its lower face and an HT lead which connects to the second plug.
Coil No. 1 and No. 2 are connected to earth via the ECM. Each coil receives a battery supply from
the main relay, via fuse 2 in the engine compartment fusebox.
Coil No. 1 is fitted above cylinder 1 and is attached to the spark plug for cylinder 1 and the HT lead
connects to the spark plug for cylinder 4.
Coil No. 2 is fitted above cylinder 3 and is attached to the spark plug for cylinder 3 and the HT lead
connects to the spark plug for cylinder 2.
Each ignition coil consists of a pair of windings wrapped around a laminated iron core. The primary
winding has a resistance of 0.7Ω and the secondary winding has a resistance of 10 kΩ.
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Fuel injectors
Figure 41
The fuel injectors are located directly under the fuel rail and connect to the intake manifold
runners. Each injector delivers fuel to the engine in a targeted, atomised spray (onto the intake
valve heads) which takes place once per cycle. Each injector opens during the intake stroke of the
cylinder it supplies.
An injector consists of a pintle type needle and seat, and a solenoid winding which lifts the needle
against a return spring. The injector nozzle delivers the fuel spray to precise areas of the intake
ports to maximise the benefits of the swirl and turbulence in the manifold and head ports.
The solenoid winding has a resistance of 13 - 16Ω at 20°C (68°F). The fuel injectors operate at a
regulated pressure of 3.5 bar (50 lbf/in2). The regulator is located on the end of the fuel rail.
The injectors receive fuel under pressure from the fuel rail and a 12 volts supply from the main
relay. To deliver fuel to the engine, the ECM has to lift the needle off the injector seat by energising
the solenoid.
If an injector fails, the engine may lose power and drivability. The ECM will store fault codes which
can be retrieved using TestBook.
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Evaporative emissions purge valve
Figure 42
The evaporative emissions (EVAP) purge valve is located in the engine compartment, on the LH
inner wing, below the E-box. The purge valve is connected via a flexible pipe to the inlet manifold.
The EVAP canister is located in the RH rear wheel arch, behind the liner.
The purge valve consists of a solenoid operated valve which is controlled by the ECM which
provides a PWM earth signal. The purge valve receives a battery feed from the main relay via fuse
1 in the engine compartment fusebox.
The EVAP purge valve controls the flow of fuel vapors from the EVAP canister to the intake
manifold of the engine. When the vehicle is being driven the ECM will purge the EVAP canister by
opening the canister purge valve, this allows the vacuum present in the intake manifold to draw
fuel vapour from the canister into the cylinders for combustion.
When fuel vapour is being removed from the canister, fresh air is allowed to enter via an automatic
one-way valve, this makes the canister ready for the next 'absorption' phase. The amount of fuel
vapour which enters the cylinders can affect the overall AFR, therefore the ECM must only open
the canister purge valve when it is able to compensate by reducing fuel injector duration.
The purge valve will only operate under the following conditions:
• Engine at normal operating temperature
• Adaptive fuelling enabled
• Closed loop fuelling enabled.
Alternator
The alternator is located on a bracket which is attached to the cylinder block on the front RH side
of the engine. The alternator is driven by a Polyvee belt from the crankshaft pulley. The alternator
converts mechanical energy into electrical energy to power the electrical systems and maintain
the battery charge.
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The alternator outputs a signal, which represents the electrical load on the vehicle systems and
the mechanical load exerted on the engine by the alternator. The signal output from the alternator
is a variable PWM signal which is proportional to the load applied to the engine.
The ECM uses the load signal to provide idle speed compensation and to reduce engine speed
fluctuations. If the load signal fails, the ECM uses a default value and stores a fault code which
can be retrieved using TestBook.
Ignition switch signal
A hardwired digital input provides an ignition on signal. When the ECM has been idle for a period
of time, it goes into 'sleep' (power saving) mode.
When the ECM receives an ignition ‘ON’ signal from the ignition switch, the ECM 'wakes up' and
energises the main relay.
Main relay
Figure 43
The main relay is located in the engine compartment fusebox which is located on the LH side of
the engine compartment.
The main relay is normally open when the ignition is ‘OFF’. When the ignition is switched ‘ON’ to
position II, the ECM provides an earth path for the relay coil which energises, closing the contacts.
A permanent battery supply is provided direct to the relay contacts. The main relay supplies
battery voltage to the following components:
• ECM
• Pre and post HO2S
• CMP sensor
• Purge valve
• Fuel injectors
• Ignition coils
• A/C relay coil
• Fuel pump relay coil
If the main relay fails, power will not be supplied to the above components and the engine will not
start. The ECM will store fault codes which can be retrieved using TestBook.
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Fuel pump relay
Figure 44
The fuel pump relay is located in the engine compartment fusebox which is positioned on the LH
side of the engine compartment. The relay is normally open when the ignition is ‘OFF’.
When the ignition is switched ‘ON’ to position II, the ECM provides an earth path for the relay coil.
With the ignition ‘ON’, the relay receives a feed from the main relay which energises the relay coil,
closing the contacts.
A permanent battery supply is provided to the relay contacts from fuse 10 in the engine
compartment fusebox, via the fuel shut-off switch. The feed passes through the relay contacts and
operates the fuel pump to pressurise the fuel system. The relay will be energised for a short time
only to pressurise the fuel system.
When the ignition switch is moved to the crank position III, the ECM will energise the relay when
the engine starts cranking and will remain energised until the engine stops.
If the engine stalls and the ECM stops receiving a signal from the CKP sensor, the ECM will
remove the earth path for the relay, stopping the fuel pump.
The fuel shut-off switch, when tripped, cuts off the power supply to the relay contacts, disabling
the fuel pump in the event of a sudden deceleration. If the fuel pump fails to operate, check that
the fuel shut-off switch is not tripped. The switch is reset by depressing the rubber cap on the top
of the switch.
If the fuel pump relay fails, power will not be supplied to the fuel pump and the engine will not start
or will stop if already running due to fuel starvation. The ECM will store fault codes which can be
retrieved using TestBook.
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Engine cooling fans
On vehicles without air conditioning (A/C) a single speed cooling fan is located behind the radiator.
The fan is controlled by the ECM via a relay located in the E-box.
On vehicles with A/C, a cooling fan is located behind the radiator, adjacent to a second similar
cooling fan used by the air conditioning system for condensor cooling. For engine cooling and air
conditioning both fans operate in parallel controlled by the ECM via a fan controller.
Cooling fan - without A/C
The ECM will energise the cooling fan relay in the E-box at a coolant temperature of 102°C (215°F)
and will go off when the coolant temperature decreases to less than 96°C (204°F).
When the engine is switched off, the ECM maintains the cooling fan in an active condition for up
to eight minutes. If the temperature does not reach a predetermined value within four minutes, the
ECM will terminate the active period. If the fan is active and the temperature falls below a
predetermined value, the ECM will terminate further fan operation.
Cooling Fan - with air conditioning
The engine cooling fan and the condensor fan are operated in parallel by the ECM via a fan
controller. The fan controller, which is located behind the radiator below the bonnet closing panel,
receives a Pulse Width Modulated (PWM) signal from the ECM. The frequency of the PWM signal,
which is varied by the ECM, is used by the fan controller to determine the output voltage supplied
to the fan motors.
The fan operation is also dependent on vehicle road speed. The ECM will calculate the required
fan speed in relation to the road speed using CAN signals received from the ABS ECU.
The ECM varies the duty cycle of the PWM signal between 10% and 90%. At duty cycles of
between 10% and 49% the fan controller will not supply any power to the fan motors. At a duty
cycle of 50%, the fan controller supplies 6 volts to the fan motors to operate them at minimum
speed. As the duty cycle increases above 50%, the fan controller increases the voltage, nonlinearly, to the fan motors up to 90%. At this point the fan motors are supplied with 12 volts and
operate at maximum speed of approximately 3000 rev/min.
When the main relay is energised, the fan controller requires a PWM signal from the ECM of
between 10% and 90% duty cycle. If this condition is not detected, the ECU will assume a fault
condition (open or short circuit) exists and operate the fans continuously at full speed when the
main relay is energised to ensure that the engine and A/C system do not overheat.
The ECM will operate the fans in response to inputs from the ECT sensor and the A/C switch and
A/C pressure sensor. Refer to A/C system for details.
When the engine is switched off, the ECM maintains the cooling fans in an active condition for up
to 8 minutes. If the temperature does not reach a predetermined value within 4 minutes, the ECM
will terminate the active period. If the fans are active and the temperature falls below a
predetermined value, the ECM will terminate further fan operation.
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Fuel tank level sensor
The ECM receives a fuel tank level signal on the CAN from the fuel tank level sensor via the
instrument pack and the ABS ECU. This signal is stored in a misfire freeze frame by the ECM for
OBD misfire detection when the fuel tank level falls to below 15% of maximum capacity.
Malfunction indicator lamp
The malfunction indicator lamp (MIL) is located in the instrument pack to inform the driver that
there is fault with an emission critical part of the engine management system. When the ignition is
switched to position II, the MIL is illuminated until the engine starts to check bulb function.
If a fault occurs on an emission related component, the ECM provides a CAN message to the
instrument pack, via the ABS ECU, to operate the MIL LED.
Tachometer drive
The tachometer drive is a CAN message output from the ECM to the instrument pack, via the ABS
modulator.
Vehicle immobilisation
The vehicle immobilisation system operates by the EWS3D immobilisation ECU transmitting a
unique code to the ECM when the ignition is switched on. If the code is recognised by the ECM it
will energise the injectors and allow the engine to start.
If no code is received or the code is incorrect, the ECM will disable the vehicle by not energising
the fuel injectors.
The immobilisation ECU also controls the starter relay and will passively disarm the starter relay
when the key is removed from the ignition switch. Rearming is performed by the turning the ignition
‘ON’ which activates a coil around the ignition key barrel.
The coil transmits a waveform signal which excites the remote handset to transmit a remobilisation signal. When the signal is received by the anti-theft alarm ECU, the starter relay will
be enabled.
Replacement ECM's are supplied blank and must learn the immobilisation ECU security code for
the vehicle to which it is fitted. When the ECM is connected to the vehicle, TestBook is required
to enable the ECM to learn the immobilisation ECU code. If a new immobilisation ECU is fitted, the
ECM will need to learn the new security code using TestBook. A procedure must be followed when
replacing the ECM or immobilisation ECU. This procedure is detailed in the Security Description
and Operation section.
Rough road detection
MEMS 3 has a misfire detection facility which is part of the On-Board Diagnostics (OBD) system.
Misfire detection is disabled when the ECM senses that the vehicle is on a 'rough road'. The
system software receives rough road signal outputs from the ABS ECU and can disable misfire
detection to prevent incorrect faults being logged by the ECM.
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The 'rough road' signal is passed from the ABS ECU on the CAN to the ECM. The CAN message
is a measure of the maximum wheel acceleration from any one of the four wheel sensors, which
is updated by the ABS ECU every 20 ms and passed to the ECM on the CAN.
Fuel shut-off switch (Inertia switch)
Figure 45
The fuel shut-off switch is located in the engine compartment on the bulkhead. In the event of a
sudden deceleration the switch removes the power supply to the fuel pump relay, stopping the fuel
pump.
The fuel shut-off switch, when tripped can be reset by depressing the rubber top of the switch. The
switch receives a power supply from fuse 10 in the engine compartment fusebox. The supply is
passed through the switch to the contacts of the fuel pump relay in the engine compartment
fusebox. The supply from the switch is also passed to the Central Control Unit (CCU) to unlock the
doors in the event of a collision causing the fuel shut-off switch to be tripped.
Throttle pedal switch (Throttle position sensor)
The throttle pedal switch is located at the top of the pedal box and secured in a cut-out hole in the
fabrication. The switch is a proximity type Hall effect switch which senses a target located on the
throttle pedal. The switch is connected on a single wire to the ECM.
The switch is normally open when the throttle pedal is at rest. When the throttle pedal is
depressed, the target on the pedal moves away from the switch causing the switch to close and
complete an earth path from the ECM. This is sensed by the ECM which uses the signal as a
throttle status to detect for stuck throttle when using Hill Descent Control (HDC). The pedal status
is compared with the inputs from the TP sensor to confirm that the throttle is being depressed.
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Diagnostics
A diagnostic socket allows the exchange of information between the ECM and TestBook or a
diagnostic tool using Keyword 2000 protocol.
The diagnostic socket is located in the driver's footwell behind the centre console.
A dedicated diagnostic (ISO 9141 K Line) bus is connected between the ECM and the diagnostic
socket and allows the retrieval of diagnostic information and the programming of certain functions
using TestBook.
The ECM uses a 'P' code diagnostic strategy and can record faults relating to the engine
management system. P codes are accessed via the ECM when TestBook is connected.
On-Board diagnostics
The MEMS 3 ECM software is programmed to meet current emission standard ECD 3. This
regulation is being introduced throughout Europe from the year 2000 and is similar to the OBD
(phase II) regulations in place in North America.
On-Board diagnostics (OBD) is concerned with the monitoring of certain functions, the failure of
which would result in an increase of exhaust emissions above legislated thresholds. The OBD is
concentrated on the engine management system.
If a fault occurs the ECM will store an applicable 'P' code in its memory and the MIL will be
illuminated. The failure codes can be accessed with TestBook. The faults stored by the ECM are
normally qualified by one of the following failure types:
• Min - the minimum expected value has been exceeded
• Max - the maximum expected value has been exceeded
• Signal - the signal is not present
• Plaus - an implausable condition has been detected
The OBD operates in the background, monitoring the operations controlled by the ECM. The
systems are monitored as the driver operates the vehicle, although the driver will be unaware that
any monitoring is being performed. Individual system tests take place as the applicable
circumstances occur.
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KV6
KV6
General
KV6 Engine
Figure 46
The KV6 is of all aluminium construction, with a 90° V configuration. The KV6 uses long cylinder
head bolts engaging in threads 70 mm below the mating face of the cylinder block to attach the
cylinder head to the cylinder block. This ensures sufficient structural stiffness to take advantage
of the compressive strength of aluminium alloy and minimise tensile loadings. There are 8 cylinder
head bolts for each cylinder head, located below the camshafts.
The engine features 24 valves, sequential fuel injection, liquid cooling and is transverse mounted.
It is controlled by a Siemens 2000 engine management system utilising a range of sensors to
constantly monitor and optimise engine performance.
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Cylinder block styructure
Cylinder block components
Figure 47
1.Clip (plastic) – coolant pump to
thermostat pipe
2.'O' ring – coolant pump to thermostat pipe
3.Pipe – coolant pump to thermostat
4.'O' ring – coolant pump to thermostat pipe
5.Clip (plastic) – coolant pump to
thermostat pipe
6.Thermostat housing
7.'O' ring – coolant outlet elbow to cylinder
block
8.Coolant outlet elbow
9.'O' ring – thermostat housing to cylinder
block
10.Blanking plate – coolant outlet
11.Seal – blanking plate
12.Engine lifting bracket – rear
13.Flywheel
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14.2nd compression ring
15.Top compression ring
16.Oil control ring
17.Piston
18.Big-end upper bearing shell
19.Big-end bearing cap
20.Big-end lower bearing shell
21.Crankshaft rear oil seal
22.Cylinder liners
23.Dowels – cylinder block to cylinder head
24.Cylinder block
25.Dowels – cylinder block to lower
crankcase
26.Engine coolant pump
27.Seal – coolant pump to cylinder block
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The cylinder block components are described below:
Cylinder block and main bearing ladder
The cylinder block is constructed of an aluminium alloy and is cast in three sections:
• Cylinder block
• Main bearing ladder
• Lower crankcase extension
For strength and rigidity, the bearing ladder is manufactured from special alloy A357TF as used
in manufacturing components in the aero industry. The main bearing ladder is secured to the
cylinder block with 16 bolts, thus creating a very rigid crankcase 'box'. A separate outer crankcase
extension adds further strength to the lower end of the cylinder block. The lower crankcase
extension is sealed to the underside of the cylinder block using Hylogrip 3000 sealant and bolted
to the underside of the cylinder block with 10 bolts. Fitted to the lower crankcase is an aluminium
alloy sump.
Pistons and cylinder liners
The aluminium alloy, thermal expansion, lightweight pistons, with semi-floating gudgeon pins,
which are offset to the thrust side, are carried on forged steel connecting rods. Pistons and
cylinder liners are supplied in two grades, 'A' and 'B' and are also colour coded to assist
identification. The pistons are marked to ensure they are correctly oriented in the cylinder liner, the
'FRONT' mark should be toward the front of the engine.
The cylinder block is fitted with 'damp' cylinder liners, the bottom stepped half of the cylinder liner
being a sliding fit into the lower part of the cylinder block. The liners are sealed in the block with a
bead of sealant applied around the stepped portion of the cylinder liner. The top of the cylinder
liner is sealed by a multi-layer steel cylinder head gasket when the cylinder head is fitted.
The cylinder liner diameters are smaller than the big-end forging of the connecting rods and need
to be removed complete with pistons and connecting rods from the cylinder block.
Connecting rods
The KV6 engine utilises forged steel H-sectioned connecting rods, with the gudgeon pin being an
interference fit in the small end of the connecting rod. The big-ends are horizontally split.
Big-end bearing diametric clearance is controlled by selective bearing shells with three grades of
thickness. The big-end upper and lower bearing shells are plain with locating tags.
Piston rings
Each piston is fitted with two compression rings and an oil control ring.
The top compression rings are chrome-plated steel. The 2nd compression rings are chromeplated cast iron. The oil control rings have stainless steel top and bottom rails and integral
expander rings.
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Crankshaft, sump and oil pump components
Crankshaft components
Figure 48
1.'O' rings – oil filter housing to oil cooler
pipes
2.Oil pressure switch
3.Oil pump and oil filter housing assembly
4.Gasket – oil pump housing
5.Bearing ladder
6.Crankshaft
7.Dipstick
8.Dipstick tube
9.Baffle plate – lower crankcase extension
10.Lower crankcase extension
11.'O' ring – oil pick-up pipe
12.Oil pick-up pipe with integral strainer
13.Connector (quick fit) – dipstick tube to
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KV6
sump
14.Oil cooler
15.Sump
16.Seal – oil drain plug
17.Oil drain plug
18.Pipe – oil filter housing to oil cooler
19.Pipe – oil cooler to oil filter housing
20.Oil filter cartridge
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The crankshaft and sump components are described below:
Crankshaft
The short, stiff crankshaft is supported on four main bearings, with each pair of crankpins mutually
offset by 30° to give equal firing intervals. Cast in spheroidal graphite iron (SG), the crankshaft has
cold rolled fillets on all journals, except the outer mains, for toughness and failure resistance. Endfloat is controlled by thrust washer halves at the top and bottom of the rear main bearing.
Main bearings
Oil grooves are provided in the upper halves of all the main bearing shells to supply oil, via drillings
in the crankshaft, to the connecting rod big-end bearings. The lower halves of the bearing shells
in the bearing ladder are plain.
Sump
The cast aluminium sump is a wet-type, sealed to the lower crankcase extension using sealant
applied to the sump flange. The sump is fixed to the lower crankcase extension using 10 bolts.
Cast aluminium sump
Figure 49
A baffle plate is fitted in the lower crankcase extension to minimise the effects of oil slosh.
Baffle plate
Figure 50
1.Baffle plate
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An oil pick-up with integral strainer is located in the centre of the sump oil well, as a source for the
supply of engine lubrication oil to the oil pump. Oil is sucked up though the end of the pick–up and
strained to prevent solid matter from entering the oil pump.
Oil pump
The oil pump is directly driven from the crankshaft. The oil pump housing includes the oil pressure
relief valve, oil filter, oil pressure switch and return/supply outlets for the engine oil cooler.
Oil filter
A full-flow, disposable canister-type oil filter is attached to a housing which is integral with the oil
pump assembly at the front of the engine.
Oil cooler
A liquid cooled oil cooler keeps the engine lubrication oil cool, under heavy loads and high ambient
temperatures.
The oil cooler is cooled by the engine cooling system and attached to a bracket secured to the
front of the sump by three bolts. Oil is delivered to and from the oil cooler through hoses connected
to the oil filter adaptor. Hoses from the engine cooling system are connected to two pipes on the
oil cooler for the supply and return of coolant.
Liquid cooled oil cooler
Figure 51
1.Oil cooler
Oil pressure switch
The oil pressure switch is located in a port at the outlet side of the oil filter. It detects when a safe
operating pressure has been reached during engine starting and initiates the illumination of a
warning light in the instrument pack if the oil pressure drops below a given value.
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Cylinder head components
Figure 52
1.Bracket – camshaft cover
2.Camshaft cover (LH similar)
3.Camshaft carrier
4.Cylinder head – RH
5.Gasket – cylinder head to cylinder block
6.Rear drive belt inner cover
7.Camshaft gear
8.Drive belt – rear camshaft
9.Rear drive belt outer cover
10.Camshaft gear
11.Seal – inlet camshaft, rear oil
12.Inlet camshaft
13.Seal – inlet camshaft, front
14.Tappets – inlet valve
15.Collets – inlet valves
16.Valve spring cap – inlet
17.Valve spring – inlet
18.Valve stem oil seal – inlet
19.Valve guide – inlet
20.Valve seat insert – inlet
21.Inlet valve
Service Training
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22.Studs – cylinder head to inlet manifold
23.Cylinder head
24.Exhaust valve
25.Valve seat insert – exhaust
26.Valve guide – exhaust
27.Valve stem oil seal – exhaust
28.Valve spring – exhaust
29.Valve spring cap – exhaust
30.Collets – exhaust valves
31.Tappets – exhaust valve
32.Seal – exhaust camshaft, rear oil
33.Exhaust camshaft
34.Seal – exhaust camshaft, front
35.Seal – filler cap
36.Filler cap
37.'O'ring – camshaft position sensor
38.Camshaft position sensor
39.Spark plug
40.Camshaft cover
41.Gasket – camshaft cover
42.Gasket – cylinder head to cylinder block
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The cylinder head components are described below:
Cylinder head
The cross-flow cylinder heads are based on a four valve, central spark plug combustion chamber,
with the inlet ports designed to induce swirl and control the speed of the induction charge. This
serves to improve combustion and hence fuel economy, performance and exhaust emissions.
LH and RH cylinder heads are identical castings.
Camshafts
Twin camshafts on each cylinder bank are retained by a camshaft carrier, line bored with the
cylinder head. The camshafts are located by a flange which also controls end-float. A crossover
drive for the exhaust camshaft, from the rear of the inlet camshaft is by a short toothed belt, which
allows for a much shorter and simpler run for the main camshaft drive belt at the front of the
engine.
The exhaust camshaft drive gears have dampers integral with the gear to minimise torsional
vibration. The inlet camshaft for the LH cylinder head incorporates a reluctor which is used in
conjunction with the camshaft position sensor to measure engine position and cycle. The camshaft
position sensor is bolted to the LH camshaft cover.
Cylinder head gasket
The KV6 utilises a multi-layer stainless steel cylinder head gasket. The gasket comprises four
stainless steel functional layers, and a stainless steel distance layer to maintain fitted thickness.
A full embossment profile is employed to seal the combustion gases and half embossments are
used to provide a durable fluid seal. Sealing characteristics are further enhanced by the
application of a fluro-elastomer surface coating to all layers of the gasket.
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Hydraulic tappets
Self-adjusting, lightweight, hydraulic tappets are fitted on top of each valve and are operated
directly by the camshaft. The valve stem oil seals are moulded onto a metal base which also acts
as the valve spring seat on the cylinder head.
Valves
The exhaust valves are of the carbon break type. A machined profile on the valve stem removes
any build up of carbon in the combustion chamber end of the valve guide. All valve seats are
machined in three planes, improving valve to seat sealing.
Exhaust valve
Figure 53
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Camshaft cover and engine cover components
Camshaft cover components
Figure 54
1.Bracket
2.Engine acoustic cover
3.Manifold chamber
4.Temperature and manifold absolute
pressure (TMAP) sensor
5.Throttle body assembly
6.Inlet manifold, RH
7.Seals – manifold chamber to LH inlet
manifold
8.HT lead clamps
9. Inlet manifold, LH
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10.Gasket – exhaust manifold to cylinder
head (LH)
11.Exhaust manifold (LH)
12.Gasket – inlet manifold to cylinder head
(LH)
13.Fuel rail
14.'O' rings – inlet manifold (RH) to top
cover
15.Gasket – inlet manifold to cylinder head,
RH
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The camshaft cover and engine cover components are described below:
Acoustic cover
A moulded plastic acoustic cover is fitted over the engine to absorb engine generated noise. Foam
is bonded on the inside surface of the acoustic cover and a rubber seal is fitted around the oil filler
cap.
Throttle body assembly
The throttle body comes in one of two variants, with and without cruise control. The correct one
must be selected if the throttle body assembly is to be replaced in service.
Inlet manifold chamber
The inlet manifold chamber is a sealed plastic assembly. The inlet manifold chamber combines
plenum resonance for good low speed torque, with variable length primary tracts for optimum mid
and high speed torque.
The throttle body assembly feeds into a 'Y' piece which separates into two secondary inlet pipes.
The secondary pipes feed into two main plenums, one for each bank of three cylinders. At the
closed end of the plenums is a balance valve, which is actuated by an electronic actuator that
connects the two plenums together.
The variable intake system uses valves and actuators to vary the overall tract length of the inlet
manifold chamber. The aluminium alloy inlet manifolds are sealed to each cylinder head with
gaskets and to the inlet manifold chamber with 'O' rings and seals.
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Lubrication circuit
Figure 55
1.Cylinder block main oil gallery
2.Cross drillings to crankshaft main
bearings
3.Oil pick-up pipe with integral strainer
4.Oil cooler
5.Oil cooler supply pipe
6.Oil filter cartridge
7.Oil cooler return pipe
8.Oil pressure switch
9.Oil pump with integral oil pressure relief
valve
The lubrication system is of the full-flow filtration, force fed type.
Oil is drawn, via a strainer and pick-up pipe in the sump, through the bearing ladder and into a
crankshaft driven oil pump which has an integral pressure relief valve. The strainer in the pick-up
pipe prevents any ingress of foreign particles from passing through to the inlet side of the oil pump
and damaging the oil pump and restricting oil drillings. The oil pressure relief valve in the oil pump
opens if the oil pressure becomes excessive and diverts oil back around the pump.
Pressurised oil is pumped through a full-flow cartridge type oil filter, mounted on the oil pump
housing. The lubrication system is designed so that a higher proportion of oil flow is directed to
the cylinder block main oil gallery while a lower proportion of oil flow, (controlled by a restrictor in
the oil filter housing), is directed to the engine oil cooler. The remainder of the oil flow from the
outlet side of the oil filter is combined with the return flow from the oil cooler before being passed
into the cylinder block main oil gallery.
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The main oil gallery has drillings that direct the oil to the main bearings. Cross drillings in the
crankshaft main bearings carry the oil to the connecting rod big-end bearings.
The oil pressure switch is located at the outlet side of the oil filter housing to sense the oil pressure
level before the oil flow enters the main gallery in the engine block. A warning lamp in the
instrument pack is illuminated if low oil pressure is detected.
Cylinder head component oil supply
Figure 56
Oil at reduced pressure is directed to each cylinder bank via two restrictors in the cylinder block/
cylinder head locating dowels, one at the front on the LH bank and the other at the rear on the RH
bank. Oil then passes through a drilling in the cylinder head to the camshaft carrier, where it is
then directed via separate galleries to the camshaft bearings and hydraulic tappet housings.
Exhausted oil from the cylinder head returns to the sump via the cylinder head bolt passages.
Crankcase ventilation
A positive crankcase ventilation system is used to vent blow-by gas from the crankcase to the air
intake system. The blow-by gas passes through a gauze oil separator in the camshaft cover, and
then through hoses into the throttle housing and inlet manifold.
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Emission control
The vehicle is fitted with the following control systems to reduce emissions released into the
atmosphere:
• Crankcase emission control
• Evaporative emissions (EVAP) control
• Exhaust emission control
The emission control systems fitted to the vehicle are designed to keep the emissions within the
legal limits, at the time of manufacture, provided that the engine is correctly maintained and is in
good mechanical condition.
Crankcase emission control system
Figure 57
1.Crankcase breather hose to throttle body
2.Crankcase breather hose to inlet
manifold
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3.Main (downstream) catalytic converter
4.Starter (upstream) catalytic converter
5.Starter (upstream) catalytic converter
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The crankcase is vented via the oil drain passages in the cylinder blocks and cylinder heads and
two ports in each camshaft cover. The larger ports in the camshaft covers are connected to the
throttle body, on the upstream side of the throttle disc, by plastic pipes. The smaller ports in the
camshaft covers are connected to the air intake duct downstream of the throttle body, also by
plastic pipes. Each of the smaller ports incorporate a restrictor and a gauze oil separator to prevent
oil being drawn out of the camshaft covers with the blow-by gases. Quick release locking collars
and 'O' rings are used for all of the pipe connections with the camshaft covers, throttle body and
air intake duct.
When the engine is running with the throttle disc closed, the depression downstream of the throttle
disc draws crankcase gases into the inlet manifold through the smaller ports in the camshaft
covers. Clean air, from the upstream side of the throttle disc, is drawn into the crankcase through
the larger ports in the camshaft covers to limit the depression produced in the crankcase.
When the engine is running with the throttle disc wide open, the upstream and downstream sides
of the throttle disc, and thus the two ports in each camshaft cover, are subjected to similar,
relatively weak, depression levels. Crankcase gases are then drawn out of both ports in each
camshaft cover, with the majority being drawn out of the unrestricted larger ports and into the
throttle body.
At interim throttle disc positions the flow of the crankcase gases varies, between those produced
at the closed and wide open throttle disc positions, depending on the depression levels produced
upstream and downstream of the throttle disc.
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Evaporative emissions control
Figure 58
1.Purge valve
2.Throttle disc
3.ECM
4.Vapour separator
5.Fuel cap filler
6.Fuel cut-off valve
7.Fuel tank
8.Two-way valve
9.Evaporative emission canister
10.Vent line to atmosphere
The EVAP control system reduces the level of hydrocarbons released into the atmosphere by fuel
vapour venting from the fuel tank. The system comprises a two way valve, vent lines, an EVAP
canister and a purge valve.
Fuel vapour, generated in the tank as the fuel heats up, is stored in the tank until the pressure is
sufficient to open the outward venting side of the two-way valve. When the two-way valve opens,
excess vapour is released through a fuel cut-off valve and a vapour separator and into the vent
line to the EVAP canister. The vapour separator prevents condensing fuel from entering the vent
line. In the EVAP canister, charcoal absorbs and stores fuel from the vapour and relatively fuel
free air is vented to atmosphere. When the fuel tank cools and vapour pressure in the tank
decreases sufficient to open the inward venting side of the two-way valve, outside air is drawn
through the EVAP canister and vent line into the tank.
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The charcoal in the EVAP canister has a finite capacity and is therefore purged of fuel when the
engine is running. Opening the purge valve draws fuel stored in the EVAP canister into the inlet
manifold, where it is burned during the combustion process. The purge valve is installed on the
inlet manifold chamber, next to the throttle body, and connected to the EVAP canister by a vent
line.
Operation of the purge valve is controlled by the ECM. When the engine is above preset
temperature and speed values, the ECM opens the purge valve and outside air is drawn through
the charcoal in the EVAP canister and into the inlet manifold, purging the charcoal of fuel.
EVAP canister
Figure 59
1.Two way valve
2.Outlet connection to purge valve
3.Atmospheric vent connection
4.Inlet connection from vapour separator
The EVAP canister contains charcoal which absorbs and stores fuel from the vapour vented from
the fuel tank while the engine is not running. When the EVAP canister is not being purged, the fuel
remains in the charcoal and clean air exits the canister via the atmospheric vent.
When the engine is running, when conditions are correct for fuel to be purged from the EVAP
canister the ECM opens the purge valve. This opens a manifold vacuum line to the EVAP canister.
Outside air from the atmospheric vent is then drawn through the charcoal, where it absorbs fuel,
and the resultant vapour is burned in the engine.
Purge valve
The operation of the purge valve is controlled by the ECM. The purge valve is installed on the inlet
manifold chamber, next to the throttle body, and connected to the EVAP canister by a vent line.
The purge valve remains closed below preset coolant and engine speed values to protect engine
tune and catalytic converter performance. If the EVAP canister is purged during cold running or at
idle, the additional enrichment of the fuel mixture delays the catalytic converter light off time and
causes erratic idle speed. When the purge valve is opened, fuel vapour from the charcoal canister
is drawn into the throttle housing for combustion.
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Two-way valve
The two-way valve in the vent line allows tank pressure to build to 0.018 to 0.050 bar (0.26 to 0.73
lbf/in2). Above this pressure, vapour is allowed to pass along the vent line to the EVAP canister.
Vapour is allowed to flow back into the fuel tank, as the pressure in the tank decreases, through
a non return valve within the body of the two-way valve.
Exhaust emission control
The engine management systems provide accurately metered quantities of fuel to the combustion
chambers to ensure the most efficient use of fuel and to minimise the exhaust emissions. To
reduce the carbon monoxide, Oxides of Nitrogen (NOx) and hydrocarbons content of the exhaust
gases, catalytic converters are installed in the exhaust systems.
In the catalytic converter the exhaust gases are passed through honeycombed ceramic elements
coated with a special surface treatment called 'washcoat'. The washcoat increases the surface
area of the ceramic elements by a factor of approximately 7000. On top of the washcoat is a
coating containing the elements which are the active constituents for converting harmful emissions
into inert by-products. Depending on the installation, the active constituents consist of palladium,
rhodium and/or platinum. Platinum and palladium add oxygen to the carbon monoxide and the
hydrocarbons in the exhaust gases, to convert them into carbon dioxide and water respectively.
The rhodium removes oxygen from the NOx to convert them into nitrogen.
The active constituents of the catalytic converters are platinum, rhodium and palladium. The
correct operation of the catalytic converters is dependent upon close control of the oxygen content
of the exhaust gas. The quantity of oxygen in the exhaust gas is monitored by the Engine Control
Module (ECM) using an input from the Heated Oxygen Sensor (HO2S) upstream of the catalytic
converters. The ECM also monitors the condition of the catalytic converters using an input from
the HO2S downstream of the catalytic converters.
Fuel delivery system
The fuel delivery system consists of a fuel tank containing an electric fuel pump to supply fuel at
a constant pressure to the engine fuel rail. A pipe, routed along the underside of the vehicle,
connects the fuel pump to the fuel rail.
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Fuel delivery system component layout
Figure 60
1.Fuel pipe
2.Fuel rail
3.Fuel pump relay
4.Injector
5.Fuel tank
6.Fuel pump
7.Vent line
8.Evaporative emissions canister
9.Filler tube
10.Filler cap
Fuel tank
The fuel tank is located on the underside of the vehicle, forward of the rear suspension subframe.
The tank is constructed from moulded plastic and is retained by a tubular cradle which is secured
to the vehicle floorpan with four bolts. A heat shield is installed on the left-hand side of the support
cradle to protect the tank from heat radiated by the exhaust system. A fire shield is installed on the
right-hand side of the support cradle.
The fuel tank has a capacity of 60 litres (15.85 US gallons). An aperture in the top surface of the
tank allows for the fitment of the fuel pump.
The fuel tank filler is located on the right hand rear wing panel and is closed by a lockable filler
cap. The plastic filler tube is connected to the tank by clamps and a rubber hose. A breather pipe
is connected to the neck of the filler tube to allow air to escape from the tank during filling. The
location of the breather tube connection on the fuel tank ensures an air space remains in the tank
after filling, to allow for heat expansion of the fuel. A vent pipe, connected to three cut-off valves
in the tank, ventilates the tank to atmosphere via the Evaporative emissions (EVAP) canister.
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The cut-off valves are float valves that prevent fuel from entering the vent pipe due to fuel slosh
or if the vehicle overturns.
Fuel tank and fuel pump
Figure 61
1.Filler cap
2.Filler tube
3.Flexible tube
4.Locking ring
5.Fuel pump and fuel gauge potentiometer
6.Fuel filter
7.Fuel tank
8.Fire shield
9.Cradle
10.heat shield
11.Vent to EVAP purge valve
12.EVAP Canister
13.Tank vent pipe to EVAP canister
14.Vent pipe
15.EVAP canister atmospheri c vent
Fuel pump
The fuel pump is electrically operated and is located in the top face of the fuel tank. A notched
locking ring retains the fuel pump in the tank and requires a special tool for removal and
installation. An access panel below the rear passenger seats provides access to the fuel pump for
maintenance. The top face of the fuel pump has an electrical connector with power and ground
connections to the pump and the fuel gauge rotary potentiometer. A quick fit coupling provides
attachment for the fuel feed pipe. A non return valve in the pump outlet prevents fuel draining from
the feed pipe back into the tank when the pump is stopped.
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The fuel pump is housed in a plastic body which incorporates a coarse mesh filter and a
serviceable fine mesh filter. The bottom part of the body forms a swirl pot which maintains a
constant fuel level at the pump pick-up. A pressure regulator in the pump body ensures that the
fuel rail and the injectors are supplied with fuel at a constant pressure of 3.5 bar (51 lbf.in2). The
regulator relieves excess fuel from the pump outlet back to the swirl pot.
The fuel pump is controlled by the Engine Control Module (ECM), which switches the fuel pump
relay in the engine compartment fuse box to control the power feed to the pump. The fuel pump
outputs more fuel than the maximum load requirement of the engine, in order to maintain a
constant pressure in the fuel rail under all running conditions.
The electrical circuit for the fuel pump incorporates an inertia switch attached to the LH front
suspension turret. In a collision above a preset deceleration speed, the inertia switch breaks the
circuit to the fuel pump to stop the delivery of fuel to the engine. The switch is reset by pressing
the rubber top.
Fuel rail
Three fuel injectors are installed in each inlet manifold and connected to the fuel rail. The injectors
are sealed in the fuel rail and the inlet manifolds by 'O' ring seals. A quick release coupling
connects the feed pipe from the fuel tank to the end of the fuel rail on the LH inlet manifold.
An accumulator is attached to the fuel rail, on the RH inlet manifold, to damp out pressure pulses
from the pump and ensure that the pressure in the fuel rail is constant (the same component
functions as the pressure regulator on vehicles with a return fuel delivery system). The
accumulator is connected by a pipe to the inlet manifold from which it receives a vacuum to aid
the damping process. A schraeder valve is installed in the 'fuel return' pipe of the accumulator to
allow pressure to be released from the fuel rail and fuel feed pipe prior to maintenance.
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Cooling system
Figure 62
a. Cold
b. Hot
The engine cooling system maintains the engine within the optimum operating temperature range
under varying ambient temperature and engine load conditions. In addition, the system cools the
engine oil, the Intermediate Reduction Drive (IRD) and the transmission fluid, and provides the
heat source for passenger compartment heating. The system consists of:
• A coolant pump
• A radiator
• A thermostat
• An expansion tank
• Interconnecting hoses and coolant rail
• Two cooling fans
Engine oil and transmission fluid are cooled by plate type heat exchangers. The engine oil cooler
is attached to the sump at the front of the engine. The transmission oil cooler is attached to the
front of the gearbox. The IRD is cooled by an internal plate type heat exchanger incorporated into
the IRD lubrication circuit.
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Coolant pump
The rotor type coolant pump is integrated into the front of the engine, between the cylinder blocks.
The pump is driven by the camshaft timing belt via a plain pulley installed on the pump rotor shaft.
The pulley also acts as an idler pulley for the camshaft timing belt.
Expansion tank
The expansion tank is installed in the rear RH corner of the engine compartment. The expansion
tank provides a reservoir of coolant and accommodates the increase in coolant volume produced
by heat expansion. A cap on the expansion tank provides a system filling point and incorporates
a pressure relief valve that releases pressure from the system if it exceeds 1 bar (14.5 lbf/in2).
Expansion pipes connect the expansion tank to the radiator and the inlet manifolds. A hose
connects an outlet on the expansion tank to the coolant rail.
Hoses and coolant rail
The coolers and the heater matrix are connected together, by hoses and the coolant rail, in a
circuit from outlets at the right front corner of the cylinder block and the top hose, to the return hose
connection on the thermostat housing. A bleed screw in the heater outlet hose enables air to be
bled from the system during filling.
Cooling fans
The cooling fans are variable speed electric fans installed in a housing attached to the rear of the
radiator. The motor of each cooling fan is connected to a cooling fan ECU installed behind a cover
in the top left corner of the cooling fan housing. An air scoop on the cooling fan housing directs
cooling air over the ECU.
Manifolds and exhaust systems
The following section is divided into four groups:
1. Inlet manifolds
2. Inlet manifold chamber
3. Exhaust manifolds
4. Exhaust system
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Inlet manifolds
Figure 63
1.Inlet manifold LH
2.Inlet manifold RH
3.Gaskets
4.Flanged bolt (14 off)
5.'O' ring (3 off)
The inlet manifold on the KV6 engine is located on the top of the engine, between the cylinder
banks. The manifolds direct intake air into the cylinders where it is mixed with fuel delivered by the
injectors prior to ignition in the cylinders. The inlet manifold comprises left and right hand cast
aluminium inlet manifolds and a plastic moulded inlet manifold chamber.
Two handed aluminium inlet manifolds are secured to the cylinder heads using fourteen bolts and
sealed with one piece composite gaskets. Three injectors, which are sealed with 'O' rings, are
located in each manifold and are retained in position by the fuel rail. The fuel rails are secured to
each manifold using two bolts. A coolant outlet is located in the left hand end of each manifold and
a vacuum take-off point is located on the left hand manifold. Three 'O' rings and three moulded
seals provide the seal between the inlet manifolds and the inlet manifold chamber.
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Inlet Manifold Chamber
Figure 64
1.Inlet Manifold Chamber
2.Seal (3 off)
3.Flanged bolt (4 off)
4.Balance valve motor – Variable Intake
System (VIS)
5.Seal
6.Power valve motor – (VIS)
7.Seal
The inlet manifold chamber is a one piece plastic moulding which is fitted on the inlet manifolds
and secured with four bolts. Three 'O' rings and three moulded seals locate in recesses and seal
between the inlet manifold chamber and the inlet manifolds.
The inlet manifold chamber features a single throttle body which feeds into a 'Y' piece, which
separates into two secondary pipes. The secondary pipes connect to two main plenums, one for
each bank of cylinders. At the closed end of the plenums is a balance valve which is operated by
an electric motor. This valve enables the two plenums to be connected together.
From the two plenums, the primary tract length to the cylinder head face is approximately 500 mm.
Each of these tracts has a side junction with a power valve leading to a short inlet tract plenum,
approximately 350 mm from the cylinder head. Each power valve is connected to a link rod which
is operated by a single electric motor.
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Variable intake system
Figure 65
1.Balance valve
2.Main plenums
3.Secondary tracts
4.Throttle housing
5.Air cleaner
6.Power valves (6 off)
7.Primary tracts
8.Short tract plenum
The VIS operates in three conditions:
• Low speed
• Mid-range
• High speed
Low speed
At low speed the balance valve and power valves are closed. This effectively allows the engine to
breathe as two, three cylinder engines, each having a separate plenum and long primary tracts.
The primary and secondary tracts and the plenum volume are tuned to resonate at 2700 rev/min,
giving peak torque at this speed.
Mid-range
For increased mid-range torque performance, the plenums are connected using the balance
valve. The power valves remain closed. This allows the engine to use the long primary tract length,
which is tuned with the balance valve to produce maximum torque at 3750 rev/min.
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High speed
At high engine speeds the balance valve remains open and the six power valves are opened. This
allows the engine to breathe from the short tract plenum via the short primary tract lengths. These
lengths and diameters are tuned to produce a spread of torque from 4000 rev/min upwards, with
maximum power produced at 6250 rev/min.
The manifold also gives an improvement in part load fuel consumption. At part load, throughout
the emissions cycle the manifold operates as at high speed. The pressure dynamics significantly
reduce the pump losses below 4000 rev/min resulting in improved fuel consumption.
Exhaust manifolds
Figure 66
1.Exhaust manifold LH
2.Gasket LH
3.Gasket RH
4.Exhaust manifold RH
Two handed, steel fabricated exhaust manifolds are fitted. Each manifold has three branches
which merge into one flanged outlet. Each manifold is sealed to the cylinder head with a composite
gasket. Four studs in each cylinder head locate each manifold which is secured with nuts.
A starter catalyst is fitted to each manifold at the point where the three branches merge. Each
manifold also has a HO2S located upstream of the pre-catalyst.
Exhaust system
The exhaust system comprises three major parts; a front pipe assembly incorporating a catalytic
converter, an intermediate pipe assembly and a tail silencer.
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Figure 67
1.Mounting rubbers
2.Silencer
3.Intermediate silencer
4.Gasket
5.Catalytic converter
6.Joint
7.Front silencer
Front pipe assembly
The front pipe is connected to the flanged connections of the left and right hand exhaust manifolds.
The front pipe locates on two studs on each manifold and is secured with nuts. A bracket near the
front flange is secured to a gearbox attachment bolt. The two manifold pipes merge into an integral
flexible pipe which in turn connects with the catalytic converter. The flexible pipe is formed into a
concertina shape which is protected by a metal shroud. The flexible pipe allows for ease of
exhaust system alignment and also absorbs engine vibrations.
A further pipe section from the catalytic converter is terminated by a flanged connection with
captive studs. This pipe section also has a threaded port which provides for the location of the post
catalyst HO2S. Refer to the Emissions section for details of catalyst and HO2S operation.
Intermediate pipe assembly
The intermediate pipe has a flange at its forward end which locates on the three studs on the front
pipe and is secured with nuts. The joint between the two flanges is sealed with a metal gasket.
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A circular silencer is located midway along the system and is braced to the pipe at each end to
resist bending. A short section of pipe from the silencer connects to another smaller rectangular
section silencer. A further pipe section from this silencer has a series of bends to allow clearance
for the suspension and terminates in an open end which mates with the tail pipe assembly. The
intermediate pipe is supported between the flange and the silencer by a welded support bracket
and mounting rubber.
Tailpipe assembly
The tail pipe assembly is of fabricated and welded construction and comprises a large capacity
silencer, a connecting pipe and two tail pipes. The curved connecting pipe is welded to the left
hand end of the silencer and mates with the intermediate pipe. The connecting pipe is a sliding fit
on the intermediate pipe and is secured with a clamp.
Two tail pipes are welded to the right hand end of the silencer and direct exhaust emissions
downwards from the right hand end of the bumper.
Technical data
The table titled 'Technical data' displays technical information regarding the KV6 2.5 24 valve
petrol engine.
Technical data
Description
Type
Cylinder arrangement
Data
2.5 litre V6 direct injection petrol, 24 valve, air assisted fuel injection, water cooled,
transverse mounted
90° V6, numbered from the front of the engine:
• Left bank cylinders 1, 3 and 5
• Right bank cylinders 2, 4 and 6
Bore
Stroke
Firing order
Compression ratio
Maximum power
Maximum torque
Valve operation
Fuel injection system:
• Make
• Type
Emissions standard
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80 mm (3.15 in)
82.8 mm (3.26 in)
1-6-5-4-3-2
10.5 :1 ± 0.5 : 1
130 kW (177 bhp) @ 6500 rev/min
240 Nm (177 lbf.ft) @ 4000 rev/min
Self-adjusting lightweight hydraulic tappets operated directly by the camshafts
Siemens engine management system.
Multi-point, air assisted fuel injection controlled by ECM and electro-mechanical
injectors with twin sprays targeted at back of inlet valves
ECD3
KV6
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General
The KV6 engine is fitted with a Siemens Engine Management System (EMS). The Siemens EMS
is an adaptive system that maintains engine performance at the optimum level throughout the life
of the engine.
The EMS consists of an Engine Control Module (ECM) that uses inputs from engine sensors and
from other vehicle systems to continuously monitor driver demand and the current status of the
engine. From the inputs the ECM calculates the Air Fuel Ratio (AFR) and ignition timing required
to match engine operation with driver demand, then outputs the necessary control signals to the
fuel injectors and ignition coils. The ECM also outputs control signals to operate the:
• Idle Air Control (IAC) valve
• Air Conditioning (A/C) compressor
• Cooling fans
• Evaporative emissions (EVAP) canister purge valve
• Fuel pump
• Variable Intake System (VIS)
The EMS interfaces with the:
• Immobilisation ECU, for re-mobilisation of the engine fuel supply
• Cruise control interface ECU, to enable the system
• Electronic Automatic Transmission (EAT) ECU, to assist with control of the gearbox
Sensor inputs and engine performance are monitored by the ECM, which illuminates a Malfunction
Indicator Lamp (MIL) if a fault is detected.
As part of the security system's immobilisation function, a vehicle specific security code is
programmed into the ECM and immobilisation ECU during production. The ECM cannot function
unless it is connected to an immobilisation ECU with the same code. In service, replacement ECM
are supplied uncoded and must be programmed using TestBook to learn the vehicle security code
from the immobilisation ECU.
A 'flash' Electronic Erasable Programmable Read Only Memory (EEPROM) allows the ECM to be
externally configured, using TestBook, with market specific or new information.
The ECM memorises the position of the crankshaft and the camshaft when the engine stops,
which allows immediate sequential fuel injection and ignition timing during cranking on the
subsequent start. The position data is lost if the battery is disconnected or the battery voltage is
too low (e.g. flat battery). After battery recharging or reconnection, during the subsequent start
sequence fuelling and ignition is delayed slightly until the ECM has determined the position of the
crankshaft and the camshaft from the CKP and CMP sensor inputs.
To achieve optimum performance the ECM is able to 'learn' the individual characteristics of an
engine and adjust the fuelling calculations to suit. This capability is known as adaptive fuelling.
Adaptive fuelling also allows the ECM to compensate for wear in engine components and to
compensate for the tolerance variations of the engine sensors.
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If the ECM suffers an internal failure, such as a breakdown of the processor or driver circuits, there
is no back up system or limp home capability. If a sensor circuit fails to supply an input, where
possible the ECM adopts a substitute or default value, which enables the engine to function, but
with reduced performance.
Engine starting
When the ignition switch is in position II a power feed is connected from the ignition switch to the
ECM. The ECM then initiates 'wake up' routines and energises the main and fuel pump relays. If
the ignition switch remains in position II without the engine running, the ECM de-energises the fuel
pump relay after approximately 2 seconds. When the ignition switch is in position II with the engine
running, or position III, the fuel pump relay is permanently energised.
When the engine cranks, the ECM initiates fuelling and ignition to start the engine. Provided a valid
mobilisation signal is received from the immobilisation ECU, the ECM maintains fuelling and
ignition control of the engine as necessary to meet driver demand. If no mobilisation code is
received from the immobilisation ECU, or the code is invalid, the ECM stops the engine after 2
seconds.
The electrical circuit from the fuel pump relay to the fuel pump is routed through the fuel cut-off
inertia switch, located below the E-box in the engine compartment. In the event of a collision the
switch breaks the circuit to prevent further fuel being delivered to the engine. The switch is reset
by pressing down the centre of the rubber cover on the top of the switch.
During the start sequence, the ECM also illuminates the MIL, as a bulb check, for 4 seconds after
the ignition switch turns to position II or until the ignition switch turns to position III.
Engine stopping
When the ignition switch is turned to position I, the ECM switches off the ignition coils, injectors
and fuel pump to stop the engine. The ECM continues to energise the main relay until the power
down functions are completed. Power down functions include engine cooling, referencing the IAC
valve stepper motor and memorising data for the next start up. When the power down process is
completed, the ECM de-energises the main relay and enters a low power mode. In the low power
mode, maximum quiescent drain is 0.5 mA.
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ECM
Figure 68
The ECM is located in the engine compartment, in the Environmental (E) box behind the battery
carrier. A dual connector provides the interface between the ECM and the vehicle wiring.
Controller Area Network (CAN) bus
The ECM is connected to the Anti-lock Braking System (ABS) modulator, EAT ECU and the
instrument pack by the CAN bus. The CAN bus is a serial communications data bus, consisting of
a pair of wires twisted together, that allows the high speed exchange of digital messages between
control units.
Engine sensors
The EMS incorporates the following engine sensors
• A Camshaft Position (CMP) sensor
• A Crankshaft Position (CKP) sensor
• An Engine Coolant Temperature (ECT) sensor
• Three Heated Oxygen Sensors (HO2S)
• An Intake Air Temperature/ Manifold Absolute Pressure (IAT/MAP) sensor
• Two knock sensors
• A Throttle Position (TP) sensor
• An accelerator pedal position sensor
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Crankshaft Position (CKP) sensor
Figure 69
The CKP sensor provides the ECM with a digital signal of the rotational speed and angular position
of the crankshaft, for use in ignition timing, fuel injection timing and fuel quantity calculations. To
determine the exact position of the crankshaft in the engine cycle, the ECM must also use the input
from the CMP sensor.
The CKP sensor is mounted on the front of the gearbox housing, in line with the outer
circumference of the torque converter. The sensing tip of the CKP sensor is adjacent to a reluctor
ring formed in the periphery of the torque converter. The reluctor ring has 58 teeth spaced at 6°
intervals. A gap equivalent to two missing teeth, 36° After Top Dead Centre (ATDC) of No. 1
cylinder, provides the ECM with a reference point.
The CKP sensor operates using the Hall effect principle. A permanent magnet inside the sensor
applies a magnetic flux to a semiconductor, which receives a power supply from the main relay.
The output voltage from the semiconductor is fed to the ECM. As the gaps between the poles of
the reluctor ring pass the sensor tip the magnetic flux is interrupted, causing a fluctuation of the
output voltage and producing a digital signal.
If the CKP sensor fails the ECM immediately stops the engine.
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Camshaft Position (CMP) sensor
Figure 70
The CMP sensor provides a signal which enables the ECM to determine the position of the
camshaft relative to the crankshaft. This allows the ECM to synchronise fuel injection for start and
run conditions.
The CMP sensor is located on the camshaft cover of the LH cylinder bank, at the opposite end to
the camshaft drive, in line with a 'half moon' reluctor on the exhaust camshaft. The reluctor
comprises a single tooth which extends around 180° of the camshaft circumference.
The CMP sensor operates using the Hall effect principle. A permanent magnet inside the sensor
applies a magnetic flux to a semiconductor, which receives a power supply from the main relay.
The output voltage from the semiconductor is fed to the ECM. As the gap in the reluctor passes
the sensor tip, the magnetic flux is interrupted, causing a fluctuation of the output voltage and
producing a digital signal.
If the CMP sensor fails during engine running, the engine will run normally until turned ‘OFF’, but
will not restart until the CMP sensor input is restored.
Engine Coolant Temperature (ECT) sensor
Figure 71
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The ECT sensor provides the ECM with a signal voltage that varies with coolant temperature. The
ECT sensor is located between the cylinder banks, between cylinders 3 and 6.
The ECT sensor consists of an encapsulated Negative Temperature Coefficient (NTC) thermistor
which is in contact with the engine coolant. As the coolant temperature increases the resistance
across the sensor decreases and as the coolant temperature decreases the sensor resistance
increases. To determine the coolant temperature, the ECM supplies the sensor with a regulated
5 volts power supply and monitors the return signal voltage.
If the ECT signal is missing, or outside the acceptable range, the ECM assumes a default
temperature reflecting a part warm engine condition. This enables the engine to function, but with
reduced driveability when cold and increased emissions, resulting from an over rich mixture, when
the engine reaches normal operating temperature. The ECM will also switch on the cooling fans
to prevent the engine and gearbox from overheating.
Intake Air Temperature/ Manifold Absolute Pressure (IAT/MAP) sensor
Figure 72
The dual IAT/MAP sensor provides the ECM with temperature and pressure signals for use in
mass air flow calculations. The IAT/MAP sensor is located on the throttle body, downstream of the
throttle plate.
IAT sensor: The IAT sensor is a NTC thermistor which is exposed to the intake air. As the intake
air temperature increases the resistance across the sensor decreases and as the intake air
temperature decreases the sensor resistance increases. To determine the intake air temperature,
the ECM supplies the sensor with a regulated 5 volts power supply and monitors the output signal
voltage. If the IAT sensor fails the ECM adopts a default temperature value of 45 °C (113 °F) and
disables adaptive fuelling. The fault may not be apparent to the driver.
MAP sensor: The MAP sensor is a piezo resistive sensor. The resistance of the sensor varies in
proportion to the pressure of the intake air. The ECM supplies the sensor with a regulated 5 volts
power supply and, from the sensor output voltage, calculates the pressure of the intake air. If the
MAP sensor signal is missing the ECM will adopt a default value based on crankshaft speed and
throttle angle. The engine will continue to run with reduced driveability and increased emissions,
although this may not be apparent to the driver.
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Knock sensors
Figure 73
The knock sensors enable the ECM to operate the engine at the limits of ignition advance, for
optimum efficiency, without combustion knock damaging the engine. The ECM uses two knock
sensors, one for each cylinder bank, located between the cylinder banks on cylinders 3 and 4.
The knock sensors consist of piezo ceramic crystals that oscillate to create a voltage signal.
During combustion knock, the frequency of crystal oscillation increases, which alters the signal
output to the ECM. The ECM compares the signal to known signal profiles in its memory. If the
onset of combustion knock is detected the ECM retards the ignition timing for a number of cycles.
When the combustion knock stops, the ignition timing is gradually advanced to the original setting.
The knock sensor leads are of different lengths to prevent incorrect installation.
Throttle Position (TP) sensor
Figure 74
The TP sensor provides the ECM with a throttle plate position signal. The TP sensor is located on
the throttle body.
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The TP sensor is a variable potentiometer that consists of a resistive track and a sliding contact.
The sliding contact is connected to the spindle of the throttle plate. The sensor receives a
regulated 5 volts supply from the ECM. As the throttle is opened and closed, the sliding contact
moves along the resistive track to change the output voltage of the sensor. The ECM determines
throttle plate position and angular change rate by processing the output voltage, which ranges
from approximately 0.14V at closed throttle to 4.36V at wide open throttle.
The TP sensor requires no adjustment in service, since the ECM adapts to any minor changes of
the upper and lower voltage limits which occur due to normal wear. However, when a new TP
sensor or ECM is fitted, a TestBook initialisation procedure must be carried out to enable the ECM
to 'fast learn' the TP sensor positions and, in the case of a new TP sensor, overwrite old data.
Without the initialisation procedure, poor throttle response and idle control may be experienced
until the ECM adapts to the voltage limits of the sensor.
If the TP signal is missing the ECM will substitute a value based on information from the IAT/MAP
sensor and CKP sensor. The engine will continue to run but may suffer from poor idle control and
throttle response.
Heated Oxygen Sensors (HO2S)
Figure 75
The EMS has three HO2S:
• One in each exhaust manifold, upstream of the starter catalytic converter, identified as LH and
RH front HO2S
• One in the exhaust front pipe immediately downstream of the main catalytic converter,
identified as the rear HO2S
The LH and RH front HO2S enable the ECM to determine the AFR of the mixture being burned in
each cylinder bank of the engine. The rear HO2S enables the ECM to monitor the performance of
the catalytic converters.
Each HO2S consists of a sensing element with a protective ceramic coating on the outer surface.
The outer surface of the sensing element is exposed to the exhaust gas, and the inner surface is
exposed to ambient air. The difference in the oxygen content of the two gases produces an
electrical potential difference across the sensing element. With a rich mixture, the low oxygen
content in the exhaust gas results in a higher sensor voltage. With a lean mixture, the high oxygen
content in the exhaust gas results in a lower sensor voltage.
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During closed loop control the voltage of the two front HO2S switches from less than 0.3 volt to
more than 0.5 volt. The voltage switches between limits every two to three seconds. This switching
action indicates that the ECM is varying the AFR within the Lambda window tolerance, to
maximise the efficiency of the catalytic converters.
Sectioned view of HO2S
1
V
A
2
3
B
M19 2959
Figure 76
A = Ambient air; B = Exhaust gases
1.Protective ceramic coating
2.Electrodes
3.Zirconium oxide
The material of the sensing element only becomes active at a temperature of approximately 300
°C (570 °F). To shorten the warm up time and minimise the emissions from a cold start, each
HO2S contains a heating element powered by a supply from the main relay. The earth paths for
the heating elements are controlled by the ECM. On start up, the current supplied to the heating
elements is increased gradually to prevent sudden heating from damaging the ceramic coating.
After the initial warm up period the ECM modulates the earth of the heating elements, from a map
of engine speed against mass air flow, to maintain the HO2S at the optimum operating
temperature.
The nominal resistance of the heating elements is 6 Ω at 20 °C (68 °F).
If a front HO2S fails the ECM adopts open loop fuelling and catalytic converter monitoring is
disabled. If the rear HO2S fails only catalytic converter monitoring is affected.
Accelerator pedal position sensor
The accelerator pedal position sensor enables the ECM to detect when the accelerator pedal is
pressed by the driver. The ECM uses the accelerator pedal position sensor input to detect a
sticking throttle, by ensuring there is genuine driver demand from the accelerator pedal when the
TP sensor input indicates that the throttle is above idle.
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The accelerator pedal position sensor is a Hall effect sensor installed in the pedal box. The sensor
consists of an inner sensor in an outer mounting sleeve. To ensure correct orientation, the sensor
is keyed to the mounting sleeve and the mounting sleeve is keyed to the pedal box. Mating
serrations hold the sensor in position in the mounting sleeve. While the accelerator pedal is at idle,
a tang on the upper end of the pedal rests against the end of the sensor. When the accelerator
pedal is pressed, the tang moves away from the sensor and induces a change of sensor output
voltage.
If the accelerator pedal position sensor input is missing, or the TP sensor input is implausible, the
ECM inhibits the throttle angle message on the CAN bus which disables the Hill Descent Control
(HDC) function of the ABS modulator and reduces the performance of the automatic gearbox
(harsh gear changes and loss of kickdown).
Ignition coils
Ignition coil
Figure 77
The ECM uses a separate ignition coil for each spark plug. The ignition coils for the LH bank spark
plugs are positioned on the forward tracts of the inlet manifold and connected to the spark plugs
with High Tension (HT) leads. The ignition coils for the RH bank spark plugs are of the plug top
design, secured to the camshaft cover with 2 screws.
Each ignition coil has 3 connections in addition to the spark plug connection; an ignition feed from
the main relay, an earth wire for the secondary winding and a primary winding negative (switch)
terminal. The switch terminal of each ignition coil is connected to a separate pin on the ECM to
allow independent switching. The ignition coils are charged whenever the ECM supplies an earth
path to the primary winding negative terminal. The duration of the charge time is held relatively
constant by the ECM for all engine speeds. Consequently, the dwell period increases with engine
speed. This type of system, referred to as Constant Energy, allows the use of low impedance coils
with faster charge times and higher outputs.
The ECM calculates dwell angle using inputs from the following
• Battery voltage (main relay)
• CKP sensor
• Ignition coil primary current (internal ECM connection)
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The spark is produced when the ECM breaks the primary winding circuit. This causes the
magnetic flux around the primary winding to collapse, inducing HT energy in the secondary coil,
which can only pass to earth by bridging the air gap of the spark plug.
Ignition related faults are monitored indirectly by the misfire detection function.
Ignition timing
The ECM calculates ignition timing using inputs from the following sensors:
• CKP sensor
• Knock sensors
• IAT/MAP sensor
• TP sensor (idle only)
• ECT sensor
At start up and idle the ECM sets ignition timing by referencing the ECT and CKP sensors. Once
above idle the ignition timing is controlled according to maps stored in the ECM memory and
modified according to additional sensor inputs and any adaptive value stored in memory. The
maps keep the ignition timing within a narrow band that gives an acceptable compromise between
power output and emission control. The ignition timing advance and retard is controlled by the
ECM in order to avoid combustion knock.
Knock control
The ECM uses active knock control to prevent combustion knock damaging the engine. If the
knock sensor inputs indicate the onset of combustion knock, the ECM retards the ignition timing
for that particular cylinder by 3°. If the combustion knock indication continues, the ECM further
retards the ignition timing, in decrements of 3°, for a maximum of 15° from where the onset of
combustion knock was first sensed. When the combustion knock indication stops, the ECM
restores the original ignition timing in increments of 0.75°.
To reduce the risk of combustion knock at high intake air temperatures, the ECM retards the
ignition timing if the intake air temperature exceeds 55 °C (169 °F). The amount of ignition retard
increases with increasing air intake temperature.
Idle speed control
The ECM controls the engine idle speed using a combination of ignition timing and the IAC valve.
When the engine idle speed fluctuates the ECM initially varies the ignition timing, which produces
rapid changes of engine speed. If this fails to correct the idle speed, the ECM also operates the
IAC valve stepper motor to vary the amount of air allowed to bypass the throttle plate. To increase
the idle speed the ECM signals the stepper motor to allow more air to bypass the throttle plate. To
decrease the idle speed the ECM signals the stepper motor to allow less air to bypass the throttle
plate. The IAC valve is also opened during deceleration to decrease the manifold vacuum and
reduce emissions.
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Misfire detection
The ECM uses the CKP sensor input to monitor the engine for misfires. As the combustion charge
in each cylinder is ignited the crankshaft accelerates, then subsequently decelerates. By
monitoring the acceleration/ deceleration pulses of the crankshaft the ECM can detect misfires.
Low fuel level: When the fuel tank is almost empty there is a risk that air may be drawn into the
fuel system, due to fuel 'slosh', causing fuel starvation and misfires. If a misfire occurs when the
fuel tank content is less than 15% (8.85 litres; 2.34 US galls), the ECM stores an additional fault
code to indicate the possible cause of the misfire.
Rough road disable: When the vehicle is travelling over a rough road surface the engine
crankshaft is subjected to torsional vibrations caused by mechanical feedback from the road
surface through the transmission. To prevent misinterpretation of these torsional vibrations as a
misfire, the misfire monitor is disabled when a road surface exceeds a roughness limit
programmed into the ECM. The roughness of the road is calculated by the ABS modulator, from
the four ABS sensor inputs, and transmitted to the ECM on the CAN bus.
Fuel injectors
Fuel injector
M19 2845A
Figure 78
A split stream, air assisted fuel injector is installed for each cylinder. The injectors are located in
the inlet manifolds and connected to a common fuel rail assembly.
Each injector contains a pintle type needle valve and a solenoid winding. The needle valve is held
closed by a return spring. An integral nozzle shroud contains a ported disc, adjacent to the
nozzles. 'O' rings seal the injector in the fuel rail and the inlet manifold.
The solenoid winding of each injector receives a 12 volt supply from the main relay. To inject fuel,
the ECM supplies an earth path to the solenoid winding, which energises and opens the needle
valve. When the needle valve opens, the two nozzles direct a spray of atomised fuel onto the back
of each inlet valve. Air drawn through the shroud and ported disc improves atomisation and
directional control of the fuel. The air is supplied from a dedicated port in the IAC valve via a plastic
tube and tracts formed in the gasket face of the intake manifolds.
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Each injector delivers fuel once per engine cycle, during the inlet stroke. The ECM calculates the
open time (duty cycle) of the injectors from:
• Engine speed
• Mass air flow
• Engine temperature
• Throttle position
The fuel in the fuel rail is maintained at a pressure of 3.5 bar (51 lbf/in2) by a pressure regulator
incorporated into the pump unit in the fuel tank. An accumulator is attached to the fuel rail on the
RH inlet manifold to damp out pressure pulses from the pump and ensure that the pressure in the
fuel rail is constant (the same component functions as the pressure regulator on vehicles with a
return fuel delivery system). The accumulator is connected by a pipe to the inlet manifold from
which it receives a vacuum to aid the damping process. A schraeder valve is installed in the 'fuel
return' pipe of the accumulator to allow pressure to be released from the fuel rail and fuel feed pipe
prior to maintenace.
The nominal resistance of the injector solenoid winding is 13 - 16 Ω at 20 °C (68 °F).
Idle air control (IAC) valve
Idle air control valve
M19 2844A
Figure 79
The IAC valve regulates the flow of throttle bypass air and the flow of air to the fuel injectors. The
throttle bypass air enables the ECM to:
• Control engine idle speed
• Provide a damping function when the throttle plate closes during deceleration, to reduce
Hydrocarbon (HC) emissions
The IAC valve is located on a port in the throttle body downstream of the throttle plate. A hose,
from the duct between the air cleaner and the throttle body, is connected to an inlet port on the
valve housing to provide a source of air from upstream of the throttle plate. A tube supplies air from
an outlet port on the valve housing to the intake manifolds, for the air assisted fuel injectors. A
stepper motor on the valve housing operates a pintle valve to control the flow of air through the
valve housing.
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The stepper motor core is rotated by the magnetic fields of two electro-magnetic bobbins set at
90° to each other. The bobbins are connected to driver circuits in the ECM. Each of the four
connections can be connected to 12 volts or earth, enabling four phases to be produced. The ECM
modulates the four phases as necessary to move the motor core and pintle valve, and so adjust
the flow of air from the inlet port to the throttle bypass and fuel injector outlet ports.
When the ignition is switched off the ECM enters a power down routine which includes referencing
the stepper motor. During referencing the ECM rotates the stepper motor fully closed to provide a
position datum for when it next needs to start the engine. The referencing procedure takes from
three to five seconds. If the ECM cannot reference the stepper motor the during power down, e.g.
due to a power failure, referencing is performed the next time the ignition is switched ‘ON’.
There are no back up idle control systems. If the stepper motor fails the idle speed may be too
high or too low, the engine may stall and/or the engine may be difficult to start.
Evaporative emissions (EVAP) canister purge valve
The ECM provides a PWM earth path to control the operation of the purge valve. When the ECM
is in the open loop fuelling mode the purge valve is kept closed. When the vehicle is moving and
in the closed loop fuelling mode the ECM opens the purge valve.
When the purge valve is open fuel vapour is drawn from the EVAP canister into the inlet manifold.
The ECM detects the resultant enrichment of the AFR, from the inputs of the front HO2S, and
compensates by reducing the duty cycle of the fuel injectors.
Variable intake system (VIS) valves
The ECM operates the two VIS valve motors to open and close the VIS valves in a predetermined
sequence based on engine speed and throttle opening. Each VIS valve motor has a permanent
power feed from the main relay, feedback and signal connections with the ECM, and a permanent
earth connection. When the engine starts, the VIS valve motors are both in the valve open
position. To close the VIS valves, the ECM applies a power feed to the signal line of the applicable
VIS valve motor. To open the VIS valves, the ECM disconnects the power feed from the signal line
and the VIS valve motor is closed by the power feed from the main relay.
Malfunction Indicator Lamp (MIL)
The MIL is located in the instrument pack and consists of an engine graphic on a yellow
background (all except NAS) or a yellow SERVICE ENGINE SOON legend (NAS). The ECM
operates the MIL by communicating with the instrument pack on the CAN bus.
Diagnostics
The ECM incorporates On Board Diagnostics (OBD) software that complies with market legislation
current at the time of manufacture. During engine operation the ECM performs self test and
diagnostic routines to monitor the performance of the engine and the EMS. If a fault is detected
the ECM stores a related diagnostic trouble code (also known as a 'P' code) in a non volatile
memory and, for most faults, illuminates the MIL. Codes are retrieved using TestBook, which
communicates with the ECM via an ISO 9141 K line connection from the diagnostic socket.
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M47R Diesel engine
M47R Diesel engine
Introduction
The diesel engine fitted to Freelander is known as the M47R. This engine is a new member of the
latest generation of diesel engines and is made in Steyr, Austria.
Equipped with a chain-driven overhead camshaft and four valves per cylinder, Freelander also
becomes Land Rover's first 'multivalve' diesel.
Common rail technology appeared for the first time at the end of 1997 when Alfa Romeo launched
the 2.4-litre 156. Mercedes then launched a 2.2-litre common rail engine in the C-class, and the
technology has also appeared in Isuzu vehicles.
Development objectives
The development objectives for the M47R diesel engine were:
• to develop a new four cylinder diesel engine featuring four valve technology and direct fuel
injection
• to reduce fuel consumption
• to maintain operating refinements and interior acoustics comparable to those on indirect
injection diesel engines
• to comply with the European commission directive stage 3 (ECD-3) exhaust emission limits
from model launch and to create the conceptional prerequisites for achieving the stringent
requirements of European on-board diagnostics (E-OBD)
• class competitive service times
Technical features
The technical features of the M47R diesel engine are:
• In-line four cylinder engine with cast iron cylinder block and light alloy cylinder head
• Four valve technology with centrally arranged injectors
• Exhaust turbocharger with intercooler
• Direct fuel injection with common rail technology and electronic diesel engine management
• Electronically controlled exhaust gas re-circulation (EGR) with hot-film mass air-flow meter
• Exhaust re-treatment by means of a diesel-specific oxidation catalytic converter
• Inspection intervals of 15,000 miles
• Swirl and tangential intake ports
• Chain driven camshafts
• Hydraulic valve adjustment
General
The M47R diesel engine is a 2.0 litre, 4 cylinder, in-line direct injection unit having four valves per
cylinder operated by twin overhead camshafts. The engine emissions comply with ECD-3
(European Commission Directive) legislative requirements and employs an Oxidising catalytic
converter, positive crankcase ventilation and exhaust gas recirculation to limit the emission of
pollutants. The unit is water cooled and turbo-charged and is controlled by an electronic engine
management system. Fuel injection features common rail technology.
The engine is controlled by a Bosch DDE 4.0 engine management system.
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The cylinder block is of cast iron construction with a cast aluminium stiffening plate bolted to the
bottom to improve lower structure rigidity. The cylinder head is cast aluminium with a moulded
plastic camshaft cover. The engine sump is a two-piece cast aluminium assembly. A moulded
plastic acoustic cover is fitted over the upper engine to reduce engine generated noise.
Cylinder block components
Cylinder block
Figure 80
1.Cylinder block
2.Gearbox closure assembly plate
3.Gasket – crankshaft rear seal housing to
engine block
4.Crankshaft rear seal housing
5.Crankshaft rear seal
6.'O' ring – crankshaft position sensor
7.Crankshaft position sensor
8.Oil pressure switch
9.Oil filter element
10.Sealing ring – oil filter
11.Sealing washers – oil filter head
12.Oil filter housing head assembly
13.Oil cooler assembly
14.'O' rings – oil cooler assembly to oil filter
housing
15.Oil filter housing
16.Gasket – oil filter housing to cylinder
block
17.Big-end bearing cap
18.Big-end bearing shells
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19.Dowels – big end bearing cap to
connecting rod
20.Connecting rod
21.Small-end bush
22.Circlip
23.Gudgeon pin
24.Piston
25.Oil control ring
26.2nd compression ring
27.Top compression ring
28.Main bearing cap
29.Alternator to engine block mounting
bracket
30.Piston cooling jet
31.Pins – ancillary chain guide to cylinder
block
32.'O' ring – cylinder block blanking plate
33.Cylinder block (front) blanking plate
34.Pin – cylinder block, front (drive chain
guide)
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The cylinder block components are described below:
Cylinder block
The cylinders and crankcase are contained in a single grey cast iron construction with hollow
beam structure. The cylinders are direct bored. Lubrication oil is supplied via lubrication jets for
piston and gudgeon pin lubrication and cooling.
Lubrication oil is distributed throughout the block via the main oil gallery to critical moving parts
through channels bored in the block which divert oil to the main bearings, and to the big-end
bearings via holes machined into the crankshaft.
An oil cooler is fitted to the side of the oil filter assembly with ports in the oil cooler mating with
ports in the oil filter assembly, to facilitate coolant and oil flow from the cylinder block. An oil
pressure switch is included in a tapping in the oil filter assembly which is used to determine
whether sufficient oil pressure is available to provide engine lubrication and cooling.
A tapping at the front right hand side of the cylinder block connects a pipe to the turbocharger by
means of a banjo connection. Oil under pressure from the oil pump provides lubrication for the
turbocharger bearings.
Cylinder cooling is achieved by coolant circulating through chambers in the engine block casting.
Note that the water jacket does not have core plugs.
Two hollow metal dowels are used to locate the cylinder block to the cylinder head, one on each
side at the front of the unit. Two additional hollow metal dowels are used to locate the timing cover
to the cylinder block.
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Engine identification number
The engine number is stamped on the right hand side of the cylinder block.
Engine identification number location
Figure 81
1.Engine identification number
Connecting rods
The connecting rods are machined 'H'-sectioned steel forgings. The big-end bearing shells are
plain split halves. The upper half bearing shell fitted to the connecting rod is treated using the
sputtering process (cathodic surface coating process) to improve its resistance to wear.
Big-end bearing shell
Figure 82
The small-end of the connecting rod has a bushed solid eye which is free to move on the gudgeon
pin. The small-end bushing is a hand-push transition fit.
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Pistons
The four pistons have graphite-compound coated aluminium alloy skirts, which are gravity die cast
and machined.
Each of the pistons has a swirl chamber machined in the head which partly contains the inlet air
during the combustion process and helps provide turbulence for efficient air/fuel mixture to
promote complete combustion. The recesses in the piston's crown also provide clearance for the
valve heads.
Indirect and direct injection piston comparison
Figure 83
a. Indirect
b. Direct
The pistons are attached to the small-end of the connecting rods by fully floating gudgeon pins
which are retained in the piston by circlips.
The pistons incorporate an oil cooling channel for piston and gudgeon pin cooling, oil being
supplied under pressure from the piston lubrication jets.
Piston rings
Each piston is fitted with two compression rings and an oil control ring.
The top ring is barrel-edged and chrome plated, the 2nd compression ring is taper-faced and the
oil control ring is chrome plated and features a bevelled ring with spring.
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Piston ring location
Figure 84
1.1st compression ring
2.2nd compression ring
3.Oil ring
Piston lubrication jets
The four lubrication jets (one for each cylinder) have a long hook-type nozzle and are fitted at the
bottom right hand side of each cylinder by two socket screws.
The jets provide lubrication to the cylinder walls, and to the piston underskirt for cooling the pistons
and lubricating the gudgeon pins and small-end bearings. The input port to each lubrication jet
mates with a port provided in each mounting position, tapped at the underside of the cylinder block
from a main gallery on the right hand side of the block.
Oil cooler and oil filter housing
The engine oil cooler assembly is located on the oil filter housing and is connected to the vehicle
cooling system. Oil from the cylinder block passes through the oil filter housing and partial flow is
directed through the oil cooler before it is returned to the cylinder block. The oil filter housing has
an integral thermostatic valve which controls the amount of oil flowing through the oil cooler,
dependent on the oil temperature.
Oil pressure switch
The oil pressure switch is located in a port in the oil filter housing. It detects when a low oil pressure
condition occurs and initiates the illumination of a warning light in the instrument pack if the
pressure drops below a given value.
High pressure fuel pump
The high pressure fuel pump supplying the common fuel rail is fixed to a flange on the front left
hand side of the cylinder block. The pump is a 3 radial piston type controlled by the Bosch DDE
4.0 engine management system and chain driven from the crankshaft at 0.75 x engine speed.
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High-pressure fuel pump
Figure 85
1.High-pressure fuel pump
2.Pressure control valve
Crankshaft position sensor
The crankshaft position sensor is mounted on the rear left hand side of the cylinder block and
works on the variable reluctance principle. This uses the disturbance of the magnetic field which
is set around the sensor, caused by the rotation of a reluctor 'target' attached to the crankshaft.
The reluctor is a steel ring with 58 teeth and a space where two teeth are missing, this is the
'target'.
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Sump, crankshaft and oil pump components
Sump, crankshaft and oil pump components
Figure 86
1.Bolt – TV damper/crankshaft pulley
2.Washer – crankshaft pulley bolt
3.TV damper and crankshaft pulley
4.Crankshaft sprocket
5.Woodruff key
6.Crankshaft
7.Main bearing shells (grooved) – upper
halves
8.No. 4 main bearing with integral thrust
washers (grooved) – upper half
9.Dowel – flywheel to crankshaft
10.Crankshaft timing impulse wheel
11.Bolts – impulse wheel to crankshaft
12.Main bearing shells (plain) – lower
13.No. 4 main bearing shell (plain with
integral thrust washers) – lower
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14.Oil pump assembly
15.Gasket – oil pick-up pipe to oil pump
assembly
16.Oil pick-up pipe and strainer
17.Dipstick
18.'O' ring – dipstick to dipstick tube
19.Dipstick tube
20.'O' ring – dipstick tube to sump
21.Sump bottom plate
22.Washer – oil drain plug sealing
23.Plug – sump oil drain
24.Gasket – sump bottom plate to sump
25.Sump
26.Gasket – sump to cylinder block
27.Oil pump sprocket
28.Oil pump drive chain
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The sump, crankshaft and oil pump components are described below:
Sump
The sump is a two piece aluminium die-cast construction. The sump assembly is sealed to the
bottom of the engine block by means of a rubber and metal gasket and 19 fixing bolts. The four
bolts at the gearbox end of the engine block are longer than the remaining 15 bolts. Liquid sealing
compound is used to seal the sump to the engine block at defined points.
The oil drain plug with sealing washer is fitted to the right hand side of the bottom plate. The bottom
plate is attached to the upper portion of the sump by means of 16 bolts, and a rubber-metal gasket
seals the interface between the two components.
A port for the dipstick tube is included in the casting on the left hand side of the sump.
An oil pick-up pipe with integral strainer locates in the centre of the sump oil pan to provide oil to
the crankshaft driven oil pump.
Stiffener plate
The stiffener plate increases the rigidity of the lower engine block and is secured to the bottom of
the cylinder block by 6 bolts.
Stiffening plate location
Figure 87
1.Stiffening plate
Oil pump
The oil pump assembly is bolted to the bottom of the cylinder block and is located in front of the
engine block stiffener plate. The pump is an internal rotor type with sintered rotors and is driven
through a chain and sprocket system from the crankshaft.
A pressure relief valve is included at the outlet side of the oil pump to restrict oil pressure at high
engine speeds by recirculating oil through the relief valve back around the pump to the inlet. The
relief valve and spring is a plunger type; when oil pressure is great enough to lift the plunger, oil
is allowed to escape past the plunger to relieve pressure and prevent further rise.
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Oil is delivered to the pump from the pick-up pipe, and the outlet side of the oil pump delivers
pressurised oil flow to the engine block main oil delivery gallery.
Oil pump and pick-up
Figure 88
1.Pump sprocket
2.Pump body
3.Pick-up pipe
Crankshaft and main bearings
The crankshaft is carried in 5 main bearings, number 4 main bearing having integral thrust
washers for controlling end-float.
Cross-drillings in the crankshaft between adjoining main and big-end bearings are used to divert
oil from the main bearings to lubricate the big-end bearings.
The crankshaft seals are made from PTFE. The front end of the crankshaft has a torsional
vibration damper with integrated pulley attached for driving the ancillary components.
Each of the bearing caps are of cast iron construction and are attached to the cylinder block by
two bolts. The bearing shells are of the split cylindrical type. The upper half shells are grooved to
facilitate the supply of lubrication oil to the bearings and fit into a recess in the underside of the
cylinder block. The lower half bearing shells are plain and fit into the bearing caps.
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Cylinder head components
Cylinder head components
Figure 89
1.Plug – cylinder head oil channel
2.Valve guide
3.Camshaft bearing cap
4.Vacuum pump bracket
5.Plugs – cylinder head (rear) oil gallery
6.Plug – cylinder head (rear) blanking
7.Engine lifting bracket (rear)
8.'O' ring – vacuum pump to cylinder head
9.Vacuum pump
10.Exhaust camshaft
11.Hydraulic tappet
12.Rocker
13.Valve spring collets
14.Valve spring retainer
15.Valve spring
16.Valve stem seal
17.Valve
18.Intake camshaft
19.Screw – oil gallery blanking
20.Glow plug
21.Coolant temperature sensor
22.Engine coolant hose
23.Gasket – coolant outlet elbow to
cylinder block
24.Cylinder head gasket
25.Cylinder head
26.Engine lifting bracket (front)
The cylinder head is of aluminium gravity die casting construction. The cylinder head is bolted to
the cylinder block by means of M12 cylinder head bolts arranged beneath each camshaft.
The cylinder head gasket is a multi-layer steel type and is available in three thicknesses. The
choice of gasket thickness is dependent on the maximum piston protrusion.
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Cylinder head gasket identification
Figure 90
1.Identification holes
The cylinder head has four ports machined at each cylinder location, two exhaust ports and two
inlet ports. One of the inlet ports is helical and functions as a swirl port, the other is arranged
laterally as a tangential port and functions as a charge port.
The cylinder head cooling system features combined longitudinal/transverse coolant flow. Coolant
outlet is through a moulded plastic outlet elbow fixed to the cylinder head by three screws at the
centre left hand side of the cylinder head. The coolant thermostat is contained in a cast assembly
at the inlet side and is bolted to the water pump which is driven from the ancillary drive belt. The
coolant temperature sensor is screwed into an aperture at the rear left hand side of the cylinder
head.
The four fuel injection nozzles are centrally mounted above each cylinder and each is fixed to the
cylinder head by means of two stud bolts. The central position of the injectors provides a
symmetrical spray pattern to the central combustion bowl of the piston.
Glow plugs are arranged centrally on the inlet side of the cylinder head, between the tangential
port and the swirl port of each cylinder.
Glow plug location
Figure 91
1.Electrical connection
2.Glow plug
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A support bracket for the camshaft driven vacuum pump is located at the rear right hand side of
the cylinder head.
Vacuum pump
The vacuum pump is located on a support bracket at the rear right hand side of the cylinder head
and is driven from the exhaust camshaft.
Camshafts
There is one exhaust camshaft and one intake camshaft. Each of the camshafts are located in five
bearings and maintained in position by five bearing caps. Each of the bearing caps are fixed to the
cylinder head by two bolts. The camshafts are made using the clear chill casting process and are
hollow cast. The cam lobes have a negative cam radius. The camshafts are driven from the
crankshaft using a simplex chain and sprocket arrangement.
Each camshaft has eight machined lobes for operating the inlet and exhaust valves through lash
adjusters and roller-type finger levers. The exhaust camshaft is machined at the rear end to
provide a drive connection for the vacuum pump.
Inlet and exhaust camshafts
Figure 92
1.Inlet camshaft
2.Exhaust camshaft
Inlet and exhaust valves
The inlet and exhaust valves are identical and have ground, solid one-piece head and stems made
from Nimonic alloy material.
The valve springs are made from spring steel and are of the parallel single-coil type. The bottom
end of each spring rests on the flange of a spring retainer which has an integral valve stem seal.
The top end of the spring is held in place by a spring retainer which is held in position at the top
end of the valve stem by split taper collets. The taper collets have grooves on the internal bore
that locate to grooves ground into the upper stems of the valves.
Valve seats and valve guides are an interference fit in the cylinder head.
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Hydraulic tappets and roller finger rockers
The valves are operated through roller-type finger rockers and hydraulic tappets, actuated by the
camshaft lobes. When the camshaft lobe presses down on the top of a finger rocker, roller
mechanism, the respective valve is forced down, opening the effected inlet or exhaust port. The
use of this type of actuation method helps reduce friction in the valve timing mechanism.
Roller-type finger rocker location
Figure 93
1.Roller-type finger rocker
The body of the hydraulic tappets contains a plunger and two chambers for oil feed and
pressurised oil. The pressurised oil is supplied to the tappets via the main oil galleries in the
cylinder head and through a hole in the side of the tappet body. The oil passes into a feed chamber
in the tappet and then through to a separate pressure chamber via a one way ball valve.
Hydraulic tappet location
Figure 94
1.Hydraulic tappet
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Oil flow from the pressure chamber is determined by the amount of clearance between the tappet
outer body and the centre plunger. Oil escapes up the side of the plunger every time the tappet is
operated, the downward pressure on the plunger forcing a corresponding amount of oil in the
tappet body to be displaced. When the downward pressure from the camshaft and finger rocker
is removed (i.e. after the trailing flank of the camshaft lobe has passed), oil pressure forces the
tappet's plunger up again. This pressure is not sufficient to effect the valve operation, but
eliminates the clearance between the finger rocker and top of the valve stem.
Camshaft cover components
Figure 95
1.Air cleaner cover
2.Acoustic cover
3.Air filter
4.Mass air flow (MAF) sensor assembly
5.Grommet – air cleaner upper
6.Duct – Air cleaner assembly to
turbocharger
7.Grommet – air cleaner lower
8.Turbocharger
9.Camshaft cover blanking plate
10.Gasket – camshaft cover to cylinder
head
11.'O' ring – camshaft sensor
12.Camshaft sensor
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13.Camshaft cover
14.Pillar bolts – camshaft cover to cylinder
head
15.Oil depression limiter (filter housing)
16.Oil filler cap
17.Plugs – camshaft cover
18.Gasket (tangential ports) – inlet
manifold
19.Inlet manifold assembly
20.Sealing ring – EGR valve to inlet
manifold
21.EGR valve
22.Gasket (swirl ports) – inlet manifold
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The camshaft cover and engine cover components are described below:
The cover is of moulded plastic construction and is used to seal off the oil chamber in the cylinder
head. It shields the oil spray from the camshaft and the chain drive gear and provides the valve
gear housing.
An oil separator for the crankcase ventilation system is mounted at the centre top of the cover,
which provides preliminary oil separation by cyclone, and fine separation using an internal yarn
wrap filter. The separator unit also contains a pressure control valve.
The camshaft cover includes an integrated air filter housing which is de-coupled from the cylinder
head to absorb and minimise the transmission of engine noise. The air cleaner is designed in the
form of an oval cartridge. The camshaft cover also provides a mounting for the mass air-flow
(MAF) sensor.
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Camshaft timing train components
Timing train components
Figure 96
1.Pin – ancillary drive chain guide (upper)
2.Timing chain guide (lower)
3.Exhaust camshaft sprocket
4.Timing chain
5.Timing chain guide (top)
6.'O' ring
7.Intake camshaft sprocket
8.Pin – timing chain guide (upper)
9.Gasket – timing chain lower cover to
cylinder block
10.Timing chain guide (upper)
11.Fuel injection pump sprocket
12.Pin – ancillary chain guide (lower)
13.Ancillary chain guide (lower)
14.Ancillary drive chain
15.Nut – fuel injection pump sprocket to
fuel injection pump driveshaft
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16.Ancillary drive belt automatic tensioner
17.Ancillary drive belt deflection pulley
18.Sealing washer
19.Ancillary drive belt automatic tensioner
pulley
20.Blanking plug – timing chain lower cover
21.'O' ring
22.Crankshaft front oil seal
23.Blanking plug – timing chain lower cover
24.Washer
25.Timing chain lower cover
26.Crankshaft Woodruff key
27.Crankshaft sprocket
28.Ancillary drive chain guide (upper)
29.Timing chain and ancillary drive chain
automatic tensioner
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The timing chain cover and timing chain components are described below:
Timing chain cover
The timing chain cover is cast and machined aluminium alloy and is attached to the cylinder block
by 14 bolts. Five bolts are used to fix the upper flange of the timing cover to the cylinder head
casting, and a further four bolts secure the front of the sump to the timing cover. The bottom of the
timing cover is located to the front face of the cylinder block by two metal dowels.
The front of the crankshaft passes through a hole in the timing cover, and an oil seal is used to
seal the interface between the front of the crankshaft and the timing cover.
Timing chains
Two chain drives are utilised. The timing chain between the crankshaft sprocket and the fuel
injection pump sprocket is a simplex type. The timing chain is contained between one fixed and
one hydraulically adjustable tensioning rail.
The chain drive from the fuel injection pump sprocket to the two camshaft sprockets is also a
simplex type. The chain between the camshaft and injection pump runs between one fixed guide
rail and a hydraulically adjustable tensioning rail to minimise chain flutter. An additional plastic
chain guide is located above the two camshaft sprockets.
The adjustable tensioning rails are of aluminium die casting construction with clip-fastened plastic
slide linings. The fixed guide rails are moulded plastic. The tensioner rails are attached to the front
of the cylinder blocks using pivot bolts which allow the tensioner rail to pivot about its axis.
The hydraulic tensioner for both chains is provided from a single unit which contains two
hydraulically operated plungers that operate on the tensioning rails at the slack side of each of the
timing chains. Pressurised oil for the adjuster is supplied through the back of the unit from an oil
supply port in the front of the cylinder block. The lateral movement in the tensioner arm causes
the timing chain to tension and consequently, compensation for chain flutter and timing chain wear
is automatically controlled.
The timing chains are oil splash lubricated via the oil pump and chain tensioner. Oil spray is
directed to the chain from several oil supply ports in the front of the cylinder block and cylinder
head.
An additional chain from the crankshaft sprocket connects to the oil pump sprocket for oil pump
operation.
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Drive chain structure
Figure 97
1.Crankshaft sprocket
2.Guide rail
3.Oil spray nozzles
4.High pressure pump sprocket
5.Oil spray nozzle
6.Guide rail
7.Oil spray nozzle
8.Camshaft sprockets
9.Tensioning rail
10.Chain tensioner
11.Tensioning rail
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Lubrication circuit
Oil from the sump is drawn up through a fabricated metal pick-up pipe which contains a mesh to
filter out any relatively large pieces of material which could cause damage to the oil pump. The
head of the pick-up is centrally immersed in the sump oil and oil is delivered to the inlet side of the
eccentric rotary pump.
Oil circuit
Figure 98
1.Hydraulic tappet gallery
2.Hydraulic tappet, exhaust side
3.Channels to camshaft bearings, exhaust
side
4.Channels to camshaft bearings, inlet side
5.Hydraulic tappet, inlet side
6.Riser channel to tappet gallery, intake
side
7.Cylinder block main gallery feed to
lubrication jets
8.Piston lubrication jets
9.Cylinder block main oil gallery feed for
crankshaft bearings
10.Oil filter housing to cylinder block
11.Oil cooler
12.Oil filter element
13.Oil filter housing
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14.Oil pump to oil filter housing channel
15.Oil pick-up pipe
16.Pressure relief valve
17.Oil pump assembly
18.Port to cylinder block main gallery, right
hand side
19.Oil feed channels to crankshaft main
bearings
20.Riser channel for chain lubrication jets
21.Pressure supply to chain tensioner
22.Pressure
supply
channel
for
turbocharger bearing lubrication
23.Out put port for turbocharger oil feed
24.Riser channel for upper chain
lubrication
25.Pressure supply for upper chain
lubrication
26.Riser channel for tappet gallery
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The oil pump is driven from the crankshaft by a chain and sprocket system. Pressurised oil from
the pump is passed through a port in the bottom of the cylinder block and is directed up to the oil
inlet port of the oil filter housing via a port in the right hand side of the cylinder block. The oil pump
contains an oil pressure relief valve which opens to allow oil to be recirculated back around the
pump if the oil pressure increases to a high enough level.
The inlet port of the oil filter housing has an integral non-return valve which allows flow into the
filter, but prevents unfiltered oil draining back out of the filter housing when oil pressure is reduced.
The oil passes through the oil filter element and out to the oil cooler. The percentage of oil flow
passed through to the oil cooler is dependent on a thermostatic by-pass valve which is integrated
into the oil filter housing. An increase in oil temperature causes the by-pass valve to open and
allow a greater percentage of oil flow to be directed through the oil cooler. The remainder of the
oil flow from the outlet side of the filter element is directed to the outlet port of the oil filter housing
where it combines with the oil flow being returned from the oil cooler before being passed back
into the cylinder block.
An oil pressure switch is included in the outlet port of the oil filter housing to sense the oil pressure
level before the oil flow enters the main oil gallery in the engine block. A warning lamp in the
instrument pack is switched 'on' if the oil pressure is detected to be too low.
Oil pressure switch location
Figure 99
1.Electrical connection
2.Oil pressure switch
3.Sealing washer
The oil entering the cylinder block main gallery passes through drillings to the crankshaft main
bearings and cross drillings in the crankshaft direct oil to the big-end bearings. An additional four
drillings in the cylinder block supply oil at reduced pressure to the lubrication jets for piston and
cylinder cooling and gudgeon pin lubrication.
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A cross channel from the left hand main oil gallery crosses to the right hand side of the cylinder
block where there is an outlet port which provides a pressurised oil supply to the turbocharger
bearings via a banjo connection and external piping.
Riser channels at the front right hand side and rear left hand side of the cylinder block are used to
channel oil to mating ports in the cylinder head and provide a source for cylinder head lubrication
and operating pressure for the hydraulic tappets.
Oil is fed through oil galleries at the left hand and right hand sides of the engine and four cross
channels from each gallery directs oil to the camshaft bearings. Lubrication oil fed to the tappets
passes up through the tappet body to the finger rockers for lubrication of the surfaces between the
finger rockers and the camshaft lobes.
Tapered plugs seal the cylinder head main oil galleries at the rear of the cylinder head, and an
additional tapered plug is included inside the cylinder head at the front of the right hand gallery.
An additional riser channel from the cylinder block left hand main oil gallery is used to supply
lubrication to the timing chain system through several outlet ports at the front of the cylinder block
and cylinder head.
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Emission control
The vehicle is fitted with the following control systems to reduce emissions released into the
atmosphere:
Emission control components
Figure 100
1.Crankcase emission control
2.Exhaust emission control
3.Exhaust gas recirculation
The emission control systems fitted to the vehicle are designed to keep the emissions within the
legal limits, at the time of manufacture, provided that the engine is correctly maintained and is in
good mechanical condition.
Crankcase emission control
Crankcase emissions are vented into the turbocharger inlet duct via a depression limiter valve
installed on the camshaft cover. A dedicated bore in the cylinder block and cylinder head connect
the crankcase to the inlet of the depression limiter valve. The outlet of the depression limiter valve
is connected to the turbocharger inlet duct by a passageway integrated into the camshaft cover
and a tube between the camshaft cover and the inlet duct.
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Depression limiter valve
Figure 101
1.Cap
2.Atmospheric vent
3.Diaphragm valve
4.Spring
5.Integral passageway
6.Housing
7.Locating arm
8.Oil separator
9.'O' ring
The housing of the depression limiter valve contains two chambers interconnected by an integral
passageway.
One chamber contains an oil separator consisting of yarn wound onto a cylindrical cage and
covered with a fibre gauze sleeve. The cage is closed at one end and open at the other. The open
end of the cage locates over one end of the integral passageway in the housing. An 'O' ring seals
the joint between the cage and the housing.
The second chamber contains a diaphragm valve and a spring. The diaphragm valve is installed
in the cap of the chamber and located, by the spring, over an outlet port into the passageway in
the camshaft cover. When the cap is installed the diaphragm valve forms a seal between the upper
and lower parts of the chamber. An atmospheric vent in the cap exposes the top of the diaphragm
to ambient pressure.
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Crankcase emissions schematic
Figure 102
a. Crankcase emissions
b. Clean air
The diaphragm valve is normally held open by the spring. With the engine running, blow-by gases
are drawn from the crankcase, through the depression limiting valve, by the depression in the
turbocharger inlet duct. Any oil in the blow-by gases is removed by the oil separator and drains
back to the sump through the bore in the cylinder block and cylinder head. The depression in the
turbocharger inlet duct varies with engine speed and load. To limit the depression in the
crankcase, the diaphragm valve controls the flow of blow-by gases through the depression limiting
valve. Crankcase pressure is sensed on the underside of the diaphragm valve and, when
crankcase pressure reduces to the preset limit, ambient pressure acting on the top of the
diaphragm valve overcomes the spring and moves the diaphragm valve to close the outlet port.
As the diaphragm valve closes, so blow-by gases begin to increase the pressure in the crankcase
again until the diaphragm valve moves to open the outlet port.
Exhaust Gas Recirculation (EGR)
During certain running conditions the EGR system directs exhaust gases into the inlet manifold to
be used in the combustion process. The principal effect of this is to reduce combustion
temperatures, which in turn reduces NOx emissions.
A vacuum operated EGR valve on the inlet manifold controls the flow of recirculated exhaust
gases. The exhaust gases are supplied to the valve through a pipe connected to the left hand end
of the exhaust manifold. From the EGR valve, the gases flow into the inlet manifold and the
turbocharger inlet.
The EGR valve is controlled by an EGR solenoid valve, on the front of the cylinder block, which
modulates a vacuum supply from the brake servo vacuum pump. The EGR solenoid valve is
controlled by the ECM. The ECM uses the input from the air flow meter to monitor EGR operation,
using the principle that an increase in EGR decreases the intake air flow.
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Exhaust gas re-circulation cooling
Land Rover is employing an exhaust gas re-circulation cooling system on diesel vehicles fitted
with automatic transmission. Due to the fuelling strategy used to compensate for any power loss
through the automatic transmission, there tends to be a slight increase in NOx emissions.
EGR cooling can reduce NOx emissions by up to 15% and particle emissions by up to 8%.
The EGR cooler is fitted in the EGR line between the exhaust manifold and the EGR valve. The
exhaust gas flows through a series of pipes surrounded by coolant.
Exhaust emission control
The engine management system provides accurately metered quantities of fuel to the combustion
chambers to ensure the most efficient use of fuel and to minimise the exhaust emissions. In
European Union markets, to further reduce the carbon monoxide and hydrocarbons content of the
exhaust gases, a catalytic converter is integrated into the intermediate pipe of the exhaust system.
Catalytic converter location
Figure 102
1.Oxidising catalytic converter
In the catalytic converter the exhaust gases are passed through honeycombed ceramic elements
coated with a special surface treatment called 'washcoat'. The washcoat increases the surface
area of the ceramic elements by a factor of approximately 7000%. On top of the washcoat is a
coating containing platinum, which is the active constituent for converting harmful emissions into
inert by-products. The platinum adds oxygen to the carbon monoxide and the hydrocarbons in the
exhaust gases, to convert them into carbon dioxide and water respectively.
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Introduction to the common rail fuel delivery system
A research company by the name of Elasis in Naples, developed common rail technology. In 1993
an Italian company produced a prototype of their new fuel injection system. Problems with the
tolerances of the injectors stopped the planned volume production and prompted the search for a
partner at the turn of the year 1993/94. Bosch bought the patents and took over Elasis.
Bosch presented the new system to the market one year earlier than any other manufacturer.
Requirements
Increasingly stringent regulations governing exhaust and noise emissions and the demand for
lower fuel consumption mean that the injection system of a diesel engine must consistently fulfil
new requirements.
• Highest possible metering accuracy over the entire service life
• Pre-injection and main injection
• It is possible to independently determine the injection pressure and injection volume for every
operating point of the engine which gives additional degree of freedom for ideal mixture
preparation
• The injection volume and pressure should be as low as possible at the start of injection to
prevent ignition delay between the start of injection and the start of combustion to obtain
smoother engine operation (pre-injection)
Functional principle
The Freelander is the first Land Rover diesel engine to be equipped with a high-pressure
accumulator fuel injection system (common rail). With this new fuel injection process, a highpressure pump delivers a uniform level of pressure to the shared fuel line (the common rail) which
serves all the fuel injectors. Pressure develops to an optimum level for smooth operation. This
means that each injector nozzle is capable of delivering fuel at pressures of up to 1300 bar.
The common rail system disconnects fuel injection and pressure generation functions. Fuel
injection pressure is generated independently of the engine speed and fuel injection volume and
is made available in the rail (high pressure fuel accumulator) for injection to the cylinders.
The fuel injection timing and fuel volume are calculated individually in the EDC control unit and
delivered to each engine cylinder by the injectors, each of which is actuated by energising the
appropriate solenoid valve.
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Advantages:
1. Fuel injection at exactly the right moment
2. Precisely metered fuel quantity
3. Constant high pressure
4. Fuel consumption optimised
5. Emission reduction
6. Very smooth engine operation
7. Pre-injection:
• The ignition delay at the point of main injection is shortened
• Combustion pressure peaks are reduced (Smoother combustion)
• Emissions are reduced
8. Main injection:
• Variable operating pressure according to engine demands
• The injection pressure remains constant over the entire injection period thus enabling more
accurate volume metering
• The main injection is responsible for torque generation
System structure
The fuel system is divided into 2 sub-systems:
• Low-pressure system
• High-pressure system
The low-pressure system features the following components:
• Fuel tank
• Advance fuel pump (in tank)
• Outlet protection valves
• In-line electric fuel pump
• Fuel filter with outlet pressure sensor
• Pressure relief valve (low pressure system)
and in the fuel return line:
• Fuel cooling control (bimetal valve)
• Fuel cooler
The high-pressure system features the following components:
• High-pressure fuel pump
• Fuel high-pressure accumulator (rail)
• Pressure control valve
• Rail pressure sensor
• Injectors
Common rail fuel system
The diesel fuel system consists of an extra, under-bonnet, fuel pump and fuel return lines. Also, a
diesel cooler is fitted to the fuel tank return line. Unlike the in-tank filter fitted to petrol derivatives,
the diesel filter is fitted externally to the tank in an under-bonnet location.
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The extra pump is fitted before the fuel filter and increases the pressure to assist the fuel through
any potential blockage of the filter during cold starts. The extra pump helps to ensure all enginefuelling requirements are satisfied in all conditions.
A pressure regulator is located after the filter and relieves fuel into the secondary pump feed.
Fuel leaves the tank and is transferred to a secondary low-pressure fuel pump. The ECM via a
single relay controls both the primary and secondary low-pressure fuel pumps. The spill return
from the high-pressure pump and injectors is returned to the tank via a connection to the right hand
section of the fuel tank.
The ECM detects pressure in the low-pressure side of the system via a pressure sensor installed
in the fuel filter head. The sensor output is required by the ECM to determine if the high-pressure
fuel pump is receiving sufficient pressure. If the ECM detects insufficient inlet pressure to the highpressure fuel pump, it will reduce engine speed and fuel rail pressure accordingly to prevent
damage to the high-pressure fuel pump.
Conventional injection characteristics
In conventional injection systems, such as the use of distributor and in-line injection pumps, only
a single injection takes place. Pressure generation is coupled to injection volume preparation.
This has the following consequences for the injection characteristics:
• The injection pressure rises as the engine speed and injection quantities increase
• The injection pressure decreases during injection
As a result:
• At low pressures small quantities are injected
• The peak pressure is more than twice the average fuel injection pressure
Peak pressure determines the load, which can be applied to the components of an injector pump
and its drive unit.
The average injection pressure is, however, important for the quality of the fuel/air mixture in the
combustion chamber.
Common rail injection characteristics
Common rail fulfils the following demands:
• It is possible to independently determine the injection pressure and injection volume for every
operating point of the engine which gives an additional degree of freedom for the ideal mixture
preparation
• After the start of combustion, it should be possible to select the injection pressure throughout
the entire period of injection
These requirements have been fulfilled in the common rail, accumulator injection system with
preliminary and main injection.
Noise and vibration characteristics are affected to a large extent by the degree of combustion.
Therefore, a carefully planned adaption of fuel injection has taken on an important role. The
influencing of the engine combustion takes place by means of a preliminary injection in the
common rail system. This makes disturbance-free combustion at lowest noise levels possible.
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Because of its modular design the system can be easily matched to various engines; the
conventional injection nozzle holder, can be substituted by the common rail injectors and the highpressure pump can be mounted on the engine. The transition from conventional system to a
common rail system can thus be made quite easily. A comparison between the conventional and
common rail component structure can be seen in table 'Component comparison'.
Component comparison
Description
High pressure generation
Pressure distribution
Supply reservoir
Injection
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Common rail system
High pressure pump
Thick high-pressure lines
Rail
Injector - electronic
Conventional system
Distributor-type injection pump
High-pressure lines
N/A
Injection nozzle - mechanical
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Fuel delivery system structure
The structure of the fuel delivery system and it's individual components are described below:
Fuel system schematic
Figure 103
1.Fuel cooler
2.High-pressure fuel pump
3.Fuel pressure control valve
4.Electronically controlled injectors (x 4)
5.Fuel rail
6.Rail pressure sensor
7.Differential pressure valve
8.Bimetallic valve
9.Filter
10.Vent to atmosphere
11.Secondary Low-pressure fuel pump
12.Restrictor
13.Supply from primary Low-pressure fuel
pump
14.Spill return to fuel tank
15.One way valve
16.Primary Low-pressure fuel pump
Fuel tank
The fuel tank is located on the underside of the vehicle, forward of the rear suspension subframe.
The tank is constructed from moulded plastic and is retained by a tubular cradle which is bolted to
the vehicle floorpan with four bolts. A reflective metallic covering shields the tank from heat
generated by the exhaust system.
The fuel tank has a capacity of 60 litres (13.2 gallons).
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An aperture in the top surface of the tank allows for the fitment of the primary low-pressure fuel
pump.
The fuel tank filler is located on the right-hand rear wing panel and is protected by a lockable cap.
The plastic tube from the filler is connected to the tank by a flexible rubber tube and secured with
clamps. A small vent pipe allows air and vapour displaced by the fuel to escape to atmosphere
during filling of the tank.
The fuel tank incorporates a 'Roll Over Valve' (ROV) to allow the vapour in the tank to escape to
atmosphere. The tank must not be over-filled to maintain a vapour space above the fuel level and
allow the tank to 'breathe'. The ROV is welded onto the top surface of the tank and is vented to
atmosphere near to the filler cap via a pipe. During normal operation the ROV is open allowing
vapour to pass to atmosphere. In the event of the vehicle being overturned the ROV shuts-off,
sealing the tank and preventing fuel flowing down the vent pipe.
Primary low-pressure fuel pump
The primary low-pressure pump is located in an aperture in the top face of the fuel tank. The pump
is sealed in the tank with a rubber seal and secured with a locking ring, which requires a special
tool for installation and removal. Access to the pump is via an access panel located below the
right-hand rear seat.
An electrical connector on top of the pump supplies power and ground connections for the pump
and the fuel gauge potentiometer. The pump receives a power supply from the fuel pump relay.
The pump is submerged in the fuel tank and draws fuel from an integral swirl pot which maintains
a constant fuel level around the pick-up. The swirl pot also mixes warm fuel returning to the tank
with cool fuel in the tank.
A float operated potentiometer is also located on the pump and provides a variable resistance to
earth for an output from the fuel gauge to the instrument pack. The potentiometer float moves with
the fuel level in the tank and the resultant resistance is interpreted by the gauge for the level of the
remaining fuel.
The pump has a connection for a fuel supply to the burning heater pump, located in the right-hand
wheel arch, on vehicles fitted with this option.
Secondary low-pressure fuel pump
The secondary low-pressure fuel pump is located in a plastic housing, adjacent to the fuel filter, in
the engine compartment on the left-hand inner wing.
The pump is a secondary in-line pump designed to aid fuel flow through the filter in cold condition.
The pump has a fuel input pipe connection at the bottom and a fuel output pipe connection to the
filter at the top. An electrical connector on the top of the pump supplies power and ground
connections for the pump motor. The pump receives a power supply from the fuel pump relay,
simultaneously with the primary pump. Both pumps are operated together under all conditions.
Fuel filter
The fuel filter is located in a plastic housing, adjacent to the secondary low-pressure fuel pump in
the engine compartment on the left-hand inner wing.
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The fuel filter cleans fuel from the fuel tank and helps prevent premature wear to delicate
components. Insufficient filtration can cause damage to pump components, pressure valves and
fuel injection nozzles.
To prevent clogging up the filter at low temperatures, there is a bimetal valve in the return line.
This valve prevents heated fuel residue from mixing with cool fuel from the tank.
Fuel pump relay
The fuel pump relay is located on a bracket on the 'A' post, adjacent to the passenger
compartment fusebox. When energised, the relay supplies power to the primary and secondary
low-pressure fuel pumps.
In the event of a fuel pump relay failure any of the following symptoms may be observed:
• Engine stalls or will not start
• No fuel pressure at the fuel rail
Low Pressure fuel sensor
The low-pressure fuel sensor is located in the fuel filter housing, adjacent to the battery box in the
engine compartment.
Low-pressure fuel sensor location
Figure 104
It supplies a signal to the ECM, which corresponds with fuel pressure in the fuel filter.
Output from the low-pressure fuel sensor is a variable voltage signal dependent upon fuel
pressure.
In the event of a low-pressure fuel sensor failure the ‘check engine’ light will be illuminated.
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High-pressure side
The high-pressure fuel pump supplies fuel to the fuel rail.
High-pressure fuel rail
Figure 105
The pump is directly driven by the engine and is located at the front of the engine block. Fuel rail
pressure is variable to allow for fuelling strategies such as noise limitation and surge control. The
maximum fuel pressure is 1300 bar.
Fuel pressure is controlled by the ECM via the fuel pressure regulator valve located at the rear of
the high-pressure fuel pump. The ECM uses the output signal from the fuel rail pressure sensor,
mounted on the end of the fuel rail, to maintain the optimum fuel pressure for the current
conditions. The fuel pressure regulator reduces pressure by diverting fuel from the high-pressure
output back to the fuel tank.
The minimum operating pressures are, 200 bar during cranking, and 300 bar during idle, failure to
reach these pressures will result in a non-start situation, stalling or erratic idle.
Fuel return system
The diverted fuel from the pressure regulator is hot, due to the pumping process within the highpressure fuel pump, and must be passed through a fuel cooler before it returns to the fuel tank. If
the fuel is not over a predetermined temperature, a bimetallic bypass valve directs the fuel to the
fuel tank.
If the fuel temperature is above the predetermined temperature, fuel is directed back to the fuel
tank via the fuel cooler.
Fuel cooler
The fuel cooler is located below the bonnet locking platform. Diesel fuel becomes heated during
pressurisation in the high-pressure pump.
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Ambient heat in the engine bay also contributes to the heating of the fuel returning to the fuel tank.
To avoid problems associated with the lower viscosity of high temperature fuel, the returning
diesel fuel is diverted into the cooler, if it is over 73 °C (163 °F), via a bimetallic valve.
Bimetallic valve
The bimetallic valve controls the fuel flow into the fuel cooler. It is located on the inlet pipe
connection to the fuel cooler. The valve contains a bimetallic strip, which moves according to the
temperature of the fuel flowing over it. If the temperature of the returning fuel is less than 73 °C
(163 °F), fuel is diverted into the inlet supply of the secondary low pressure pump, with any
remaining fuel being returned to the swirl pot in the tank. If the temperature of the returning fuel is
more than 73 °C (163 °F), the bimetallic valve diverts the fuel through the fuel cooler before it
returns to the swirl pot in the tank.
Pressure relief valve
The five-port pressure relief valve is located at the bottom of the left-hand inner wing, near the bulk
head. The valve is manufactured from moulded plastic and is secured to the inner wing with a
plastic clip.
The valve intersects the fuel return line from the fuel cooler. The valve also intersects the pressure
supply to the secondary low-pressure pump. A connection to this line joins the fuel return line from
the bimetallic valve to the fuel cooler return line to allow returning fuel to recirculate through the
secondary pump.
Fuel pressure control valve
The pressure control valve is mounted on the high-pressure pump and controls the fuel pressure
within the fuel rail.
Pressure control valve location
Figure 106
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It is an electrically operated solenoid valve controlled by the ECM with only two states, open and
closed. When de-energised, the valve is held closed by a spring, diverting fuel to the return line.
This decreases the fuel pressure in the fuel rail. In this state fuel rail pressure is approximately 100
bar. When energised, the valve is closed, allowing maximum fuel pressure in the fuel rail. This
pressure can reach approximately 1300 bar. The ECM controls the fuel rail pressure by operating
the pressure control valve with a pulse width modulated signal. The longer the opening time (duty
cycle) of the valve, the lower the pressure in the fuel rail. The shorter the opening time (duty cycle)
of the valve, the higher the pressure in the fuel rail.
The pressure control valve receives a PWM signal of 0-12 volts from the ECM. ECM actuation of
the pressure regulator is determined by the following:
• Fuel rail pressure
• Engine load
• Accelerator pedal position
• Engine temperature
• Engine speed
In the event of a pressure regulator failure, any of the following symptoms may be observed:
• Engine will not start
• Severe loss of power
• Engine stalls
Electronic fuel injector
There are four electronic fuel injectors (one for each cylinder), each located in the centre of a
cylinder's four valves.
Injector location
Figure 107
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The electronic fuel injectors are supplied with fuel from the fuel rail and deliver finely atomised fuel
directly into the combustion chambers. Each injector is controlled individually by the ECM
according to the firing order. The injectors are provided with a 80-volt power supply from the
capacitor in the ECM. The ECM provides the earth path for the electronic fuel injectors. By using
an injection/timing map within its memory, the ECM is able to determine precise pilot and main
injection timing for each cylinder.
If battery voltage falls to between 6 and 9 volts, the electronic fuel injector operation is restricted,
affecting the engine maximum speed range and idle speed.
Input to the electronic fuel injectors takes the form of electrical pulses (80V) from the capacitor in
the ECM. The length of each pulse determines the amount of fuel injected.
In the event of a fuel injector failure, any of the following symptoms may be observed:
• Engine misfire
• Idle faults
• Reduced engine performance
• Reduced fuel economy
• Difficult cold-start
• Difficult hot-start
• Increased smoke emissions
Fuel rail pressure sensor
The fuel rail pressure sensor is located on the end of the fuel rail.
Fuel rail pressure sensor location
Figure 108
A diaphragm located within the sensor is in contact with the pressurised fuel. An electronic
resistive element, attached to the diaphragm, distorts as the diaphragm changes in shape due to
the pressure exerted by the fuel. The resistance values are converted into an analogue voltage
within the pressure sensor and the ECM then processes this signal. The ECM compares the signal
to stored values to calculate current fuel pressure.
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The fuel rail pressure sensor consists of the following components:
• Sensor housing with electrical connection
• Printed circuit board with electrical evaluation switch
• Diaphragm with integrated sensor element
The electrical input, to the fuel rail pressure sensor, is a 5 volts supply from the ECM. Output is an
analogue voltage between 0.5 - 4.5 volts.
In the event of a fuel rail pressure sensor failure, any of the following symptoms may be observed:
• Engine will not start
• Severe loss of power
• Engine stalls
Cooling system
The cooling system employed is the by-pass type, allowing coolant to circulate around the engine
and the heater circuit while the thermostat is closed. The cooling systems primary function is to
maintain the engine within an optimum temperature range under changing ambient and engine
operating conditions. A secondary function of the cooling system is to provide additional cooling
for the intermediate reduction drive (IRD) and to provide heating for the passenger meeting
The cooling system comprises:
• A radiator
• An IRD cooler
• A coolant pump
• A thermostat
• An expansion tank
• Two cooling fans
• Connecting hoses and pipes
• A fuel burning heater (selected markets only)
The coolant is circulated by a centrifugal type pump mounted on the front of the engine and driven
by the ancillary drive 'polyvee' belt. The coolant pump circulates coolant around the cylinder block
and cylinder head, to the radiator, engine oil cooler, transmission oil cooler (automatic, selected
markets only) and heater matrix via the coolant hoses.
The thermostat is located in a housing attached to the coolant pump on the inlet side of the cooling
circuit. This provides a more stable control of the coolant temperature in the engine.
When the engine is cold, the thermostat is closed and the coolant is prevented from circulating
through the radiator. Coolant is able to circulate through the by-pass and heater circuits.
As temperature increases, the thermostat gradually opens, bleeding cool fluid from the radiator
bottom hose through the pump and into the cylinder block. This allows hot coolant to flow from the
cylinder block to the radiator through the top hose, balancing the flow of hot and cold fluid to
maintain the optimum operating temperature. When the thermostat opens fully, the full flow of
coolant passes through the radiator.
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The radiator is a cross flow type with an aluminium matrix and moulded plastic end tanks. The
radiator end tanks have brackets which allow for the attachment of the fan assembly, intercooler
and, if fitted, air conditioning system condenser. The bottom of the radiator is located in rubber
bushes supported by plastic brackets which are clipped into the body longitudinals. The top of the
radiator is located in rubber bushes secured by brackets fitted to the bonnet locking platform.
The radiator top hose is connected to a coolant outlet elbow which is bolted to the cylinder head.
The elbow also has a connection for the feed to the fuel burning heater (if fitted) or the heater
matrix. The radiator bottom hose is connected to a pipe which is routed around the front of the
engine and is connected to the coolant pump housing.
For additional air-flow through the radiator matrix, particularly when the vehicle is stationary, two
electric cooling fans are fitted to the rear of the radiator.
The temperature of the cooling system is monitored by the engine control module (ECM) via
signals from the engine coolant temperature sensor (ECT) sensor, which is mounted in the
cylinder head.
The cooling system is also used to cool the IRD. The IRD oil is cooled with fluid from the cylinder
block. The fluid passes through a plate type heat exchanger located in the IRD. The plate contains
waterways which cool the IRD oil and recirculates the coolant via the heater circuit.
A bleed screw is installed in the return pipe from the heater matrix. This screw is used to bleed air
from the cooling system during filling.
Inlet and exhaust manifolds
The inlet manifold directs cooled compressed air from the turbocharger and intercooler into the
cylinders, where it is mixed with fuel from the injectors. Exhaust gases from the exhaust manifold
can also be directed into the inlet manifold via a pipe from the exhaust manifold and an Exhaust
Gas Recirculation (EGR) valve on the inlet manifold. The exhaust manifold allows combustion
gases from the cylinders to leave the engine where they are directed into the turbocharger and
exhaust system.
The exhaust system is attached to the turbocharger and is directed along the underside of the
vehicle to emit exhaust gases from a tailpipe at the rear of the vehicle. An oxidation catalytic
converter is installed midway along the system and a tail silencer is located at the rear of the
vehicle.
Exhaust manifold
The cast iron exhaust manifold is secured to the cylinder head using eight studs with nuts. Two
metal gaskets seal the manifold to the cylinder head with a turbocharger.
A flanged connection on the underside of the manifold provides for the attachment of the
turbocharger. The turbocharger is attached to the flange with three bolts and sealed with a metal
gasket.
A second flange, located on the left hand end of the manifold provides the connection point for the
EGR pipe. The pipe flange is secured to the manifold with two bolts. There is no gasket used
between the EGR pipe and the exhaust manifold.
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Turbocharger
For the first time, Land Rover are using a variable nozzle turbine (VNT) with boost pressure of up
to 2.1 bar (new turbocharging range).
The VNT makes it possible to vary the exhaust gas flow of the turbine, dependent on engine
operation. Closing the guide vanes results in a reduction of the exhaust gas flow and an increase
in the flow rate of exhaust gas to the turbine wheel. This improves the power transfer to the turbine
wheel and compressor, particularly at low engine speeds, thus increasing the boost pressure. The
guide vanes are opened progressively as the engine speed increases so that the power transfer
always remains in balance with the required charger speed and the required boost pressure level.
Variable turbine geometry facilitates better use of the exhaust gas energy so as to further improve
the efficiency of the turbocharger and thus of the engine, compared to the more conventional
'wastegate control'.
Variable nozzle turbine
Figure 109
1.Control cell
2.Control rod
3.Turbine wheel
4.Compressor housing
5.Bearing housing
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6.Adjustment ring
7.Guide vanes
8.Turbine housing
9.Compressor wheel
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Advantages:
• High torque at both high and low engine speeds
• Continuous and optimum adjustment for all engine speeds
• No wastegate valve required, exhaust energy is better utilised, less back-pressure in
conjunction with same compressor work
• Low thermal and mechanical load improves engine power output
• Low emissions
• Optimised fuel consumption over the entire engine speed range
When the control cell has no vacuum, the guide vanes contact angle, of the VNT vane mechanism,
is larger; for example, the flow rate to the turbine wheel is reduced. The boost pressure decreases.
Variable nozzle turbine vane mechanism in the open position (no vacuum)
Figure 110
1.Exhaust turbine
2.Guide vanes
When vacuum is applied to the control cell, the contact angle of the guide vanes is small; for
example, the flow rate to the turbine is increased. The boost pressure increases.
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Variable nozzle turbine vane mechanism in the closed position (full vacuum)
Figure 111
1.Exhaust turbine
2.Guide vanes
The turbochargers characteristic map is controlled by the engine control module (ECM) via a
vacuum modulator. This allows the vacuum to be controlled between 0 mBar and, approximately,
640 mBar depression (vanes fully closed).
Vane guide spacing
Figure 112
1.Open
2.Closed
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The exhaust turbocharger features an emergency mode function if the vacuum system should fail.
If no vacuum is applied, the vanes are set in the open position. This means the engine develops
less torque in the lower speed range.
Inlet manifold
The inlet manifold is a one piece plastic moulding with inlet tracts feeding intake air into the
cylinder head ports directly in the cylinder head and via the camshaft cover. The manifold is
secured to the cylinder head using four studs with nuts and one bolt, all incorporating sealing
washers and compression limiters.
The manifold is secured to the camshaft cover with eight bolts incorporating compression limiters.
Sealing between the manifold, cylinder head and camshaft cover is achieved using moulded
rubber seals located in recesses in the manifold.
A boost pressure sensor is located in the right hand end of the inlet manifold. The sensor is
secured to the manifold with a bolt and sealed with an 'O' ring. On the left hand end of the manifold,
four threaded holes provide for the attachment of the EGR valve. The valve is sealed to the
manifold with an 'O' ring.
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Inlet manifold components
Figure 113
1.Inlet manifold
2.Seal (4 off)
3.Seal (4 off)
4.Bolt and compression limiter (8 off)
5.Nut (4 off)
6.Bolt
7.Seal (5 off)
8.Seal (5 off)
9.Compression limiter (5 off)
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Technical data
The following tables are divided into two groups, 'General technical data' and 'Fuel system
technical data'.
General technical data
Description
Engine designation
Model type
Cylinder arrangement
Firing order
Compression ratio
Capacity
Bore
Stroke
Maximum power
Maximum torque
Injection system
Emission standard
Head gasket
Valve train
Intake ports
Turbocharger
Data
M47R
2.0 litre, direct injection, 16 valve, DOHC, turbo charged and intercooled
4 in-line, transverse, No.1 cylinder at front of engine
1-3-4-2
18.1 ± 0.5:1
1950 cm3
84.00 mm (3.307 in.)
88.00 mm (3.465 in.)
85 kW (116 bhp) @ 4000 rev/min.
260 Nm (192 lbf.ft) @ 1750 rev/min
Common rail direct injection (1350 bar typical) controlled by a Bosch DDE 4.0 engine
management system
ECD3
Multi layer steel, 3 sizes
Chain driven camshafts, roller finger levers and hydraulic valve adjustment
One high swirl helical port and one tangential port
Garrett GT1749 VNT
Fuel system technical data
Description
System
Fuel specification
Pressure control valve setting
Fuel tank pump
Fuel pump output
Fuel injection pump
Fuel pump drive
Pressure control valve limit
Injector make
Nozzle type
Position
Injector operating pressure
Pre - injection
Main injection
160
M47R Diesel engine
Data
Common rail, direct injection
EN590 Diesel
350 kPa (3.5 bar)
Electric, in fuel tank
250 kPa (2.5 bar)
Bosch CP1 mechanical high-pressure pump
Crankshaft driven chain at 0.75 engine speed
22 bar
Bosch
DSLA 145P 868
Central
250 - 1340 bar
60° BTDC
20° BTDC
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Electronic diesel control
Electronic diesel control
General
The M47R engine has an Electronic Diesel Control (EDC) engine management system. The
system is controlled by an Engine Control Module (ECM) and is able to monitor, adapt and
precisely control the fuel injection. The ECM uses multiple sensor inputs and precision control of
actuators to achieve optimum performance during all driving conditions.
The advantages of the system are:
• Greater fuel economy.
• Reduced exhaust emissions.
• Reduced engine noise.
• More effective cold starting.
• Smoother engine operation.
The ECM controls fuel delivery to all four cylinders via a Common Rail (CR) injection system. The
CR system uses a fuel rail to accumulate highly pressurised fuel and feed four electronically
controlled fuel injectors. The fuel rail is located in close proximity to the four fuel injectors, which
maintains full system pressure at each injector at all times.
The ECM utilises the drive by wire principle for acceleration control. There are no control cables
or physical connections between the accelerator pedal and the engine. Accelerator pedal demand
is communicated to the ECM by the Accelerator Pedal Position (APP) sensor, which is installed
on the pedal box. A variable reading from the throttle potentiometer enables the ECM to determine
the position, and the rate and direction of movement of the accelerator pedal. The ECM uses this
information to facilitate the correct engine response.
The ECM controls the Exhaust Gas Recirculation (EGR) system which is fitted to reduce the
formation of oxides of nitrogen (NOx). This group of gases is formed in the combustion chamber
under conditions of high temperature and pressure. It is not desirable to reduce the compression
ratio, so the ECM reduces the combustion temperature by introducing a controlled volume of inert
gas into the cylinders on the induction stroke.
The inert gas used is exhaust gas, which is freely available. It is directed from the exhaust
manifold, via a control valve, into the intake manifold. The flow of gas is monitored by the ECM
using the MAF sensor. The EGR system is not required until the engine is hot, and is turned off
during engine idling and wide open 'throttle' to preserve smooth operation and driveability.
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The ECM processes information from the following input sources:
• Brake switch.
• Clutch switch (manual gearbox models).
• Crankshaft Position (CKP) sensor.
• Camshaft Position (CMP) sensor.
• Anti-lock Brake System (ABS) ECU.
• Engine Coolant Temperature (ECT) sensor.
• Boost Pressure (BP) sensor.
• Low side fuel pressure sensor.
• throttle potentiometer.
• Mass Air Flow/ Intake Air Temperature (MAF/ IAT) sensor.
• Fuel rail pressure sensor.
• Controller Area Network (CAN).
The input from the sensors constantly updates the ECM with the current operating condition of the
engine. Once the ECM has compared current information with map information within its memory,
the ECM can make any required adjustment to the operation of the engine via the following
actuators:
• EGR modulator.
• Glow-plug relay.
• Fuel pressure regulator valve.
• Electronic fuel injectors.
• Cooling fan relay.
• A/C compressor clutch relay.
The ECM also communicates with other systems on the vehicle, both receiving information used
to influence fuelling and transmitting information of importance to the other systems.
The systems are as follows:
• ABS ECU.
• Electronic Automatic Transmission (EAT) ECU.
• Glow-plug relay.
• Instrument pack.
• Immobilisation ECU.
• Cruise control interface ECU.
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Engine Control Module (ECM)
ECM
M19 2774A
Figure 114
The ECM has a steel casing to provide protection from electromagnetic radiation and is located in
the E box in the engine compartment.
The ECM contains data processors and memory microchips. The output signals to actuators are
in the form of earth paths provided by driver circuits contained within the casing. The ECM driver
circuits produce heat during normal operation and dissipate this heat via the casing. The airflow
around the ECM should not be obstructed. There are regulated voltage outputs to some sensors
which use less than 12 volts to avoid voltage drop during engine cranking.
The ECM cannot be tested directly, diagnosis must be performed by ensuring that inputs and
outputs conform to specifications. TestBook is available for this purpose. If the ECM is to be
replaced, the new ECM will be supplied 'blank' and must be configured to the vehicle using
TestBook. When the ECM is fitted to the vehicle it must also be synchronised to the immobilisation
ECU using TestBook. Engine control modules must not be swapped between vehicles.
Inputs and outputs
The ECM is connected to sensors fitted to the engine which allow it to monitor engine operating
conditions. The ECM processes these signals and decides the actions necessary to maintain
optimum engine performance in terms of driveability, fuel efficiency and exhaust emissions. The
memory of the ECM is programmed with instructions for how to control the engine, this is known
as the strategy. The memory also contains data in the form of maps which the ECM uses as a
basis for fuelling and emission control. By comparing the information from the sensors to the data
in the maps, the ECM is able to calculate the various output requirements. The ECM contains an
adaptive strategy which updates the system when components vary due to production tolerances
or ageing
The ECM has an interface of 134 pins via five connectors providing both input information and
output control. Not all 134 pins are used.
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Vehicle speed signal
Vehicle speed is an important input to the ECM strategies and comes from the ABS ECU. The
ABS ECU derives the speed signal for the ECM from the front LH ABS sensor. The frequency of
this signal changes in accordance with road speed. The ABS ECU transmits the road speed on a
hardwired connection to the ECM as a Pulse Width Modulated (PWM) signal. The ECM requires
this signal to determine the following:
• How much to reduce engine torque during gear changes (automatic gearbox models).
• When to allow cruise control.
• Cruise control operation.
• For implementation of idle strategy when vehicle is stationary.
Communication
The use of digital communication provides advantages in performance and reliability over
conventional analogue systems. Digital systems transmit information as a series of pulses along
a single wire, or twisted pair of wires. The wires may be connected to various components in a
system, this common information circuit is known as a databus.
There are two databus circuits which connect directly to the ECM:
• CAN bus: used for high speed applications such as ECM, EAT ECU and traction control
functions.
• ISO 9141-2 K line bus: used for communication with TestBook and other diagnostic tools
using Keyword 2000 protocol.
Throttle potentiometer
Throttle potentiometer
M19 2761A
Figure 115
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The throttle potentiometer sensor is located on the pedal box in the driver's footwell. The throttle
potentiometer consists of two resistance tracks and two sliding contacts, effectively a pair of
potentiometers, connected to the accelerator pedal assembly. The use of a pair of identical
sensing elements ensures a position signal is still provided even if one of the sensing elements
develops a fault; this is required because there is no mechanical linkage between the accelerator
pedal and the ECM. As the accelerator pedal is depressed, the sliding contacts move along the
resistance tracks to change the output voltage of the sensor.
By monitoring the voltage outputs from the APP, the ECM is able to determine the position, rate
of change and direction of movement of the accelerator pedal. It will also store the voltages which
correspond with closed 'throttle' and wide open 'throttle' and will adapt to new ones in the event of
component wear or replacement.
The ECM uses the APP voltage to determine closed 'throttle' position to instigate idle speed
control, and to enable the overrun fuel reduction strategy.
The throttle potentiometer signal is also broadcast on the CAN bus, where it is used by the EAT
ECU to determine the correct point for gearshifts and kickdown.
The connector and sensor terminals are gold plated for corrosion resistance and temperature
stability, care must be exercised when probing the connector and sensor terminals
The ECM supplies the throttle potentiometer with a regulated 5 volts supply and an earth path for
the resistive tracks. The output signals vary according to the position of the accelerator pedal. The
throttle potentiometer earth also acts as a screen to protect the integrity of the signal.
If the throttle potentiometer signal fails, the ECM increases the idle speed to 1,250 rev/min, and
the engine speed will not increase when the accelerator is depressed.
In the event of an throttle potentiometer signal failure, the following symptoms may be observed:
• No accelerator response.
• Failure of emission control.
• Automatic gearbox kickdown inoperative.
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Crankshaft Position (CKP) sensor
Crankshaft position sensor
Figure 116
1.Crankshaft sensor
2.Seal
3.Electrical connection
The CKP sensor is located in the engine block, beneath the starter motor, with its tip adjacent to
the outer circumference of the crankshaft reluctor ring.
The CKP sensor works on the variable reluctance principle. This uses the disturbance of the
magnetic field which is set up around the CKP sensor, caused by the rotation of a reluctor 'target'
attached to the crankshaft. The reluctor is a steel ring with 58 'teeth' and a space where two teeth
are 'missing'. The teeth, and spaces between, each represent 3° of crankshaft rotation. The two
missing teeth provide a reference for angular position. As the reluctor rotates adjacent to the
sensor tip, a sinusoidal voltage waveform is produced which can be interpreted by the ECM into
crankshaft angular position and velocity.
The signal from the CKP sensor is required by the ECM for the following functions:
• To determine fuel injection timing.
• To enable the fuel pump relay circuit (after the priming period).
• To produce an engine speed message for broadcast on the CAN bus for use by other
systems.
The two pins on the sensor are both outputs. To protect the integrity of the CKP signal the cable
incorporates a screen. The cable screen earth path is via the ECM. Correct CKP sensor outputs
are dependent upon the air gap between the tip of the CKP sensor and the passing teeth of the
reluctor ring. The CKP air gap is not adjustable in this application.
In the event of a CKP sensor signal failure any of the following symptoms may be observed:
• Engine cranks but fails to start.
• Engine misfires.
• Engine runs roughly or stalls.
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Camshaft Position (CMP) sensor
Camshaft position sensor
M19 2762A
Figure 117
The CMP sensor is located on top of the engine on the camshaft cover. This sensor is a Hall effect
sensor producing one pulse for every camshaft revolution. The CMP sensor is only used on start
up to synchronise the ECM programme with the CKP signal. This is to identify number one cylinder
for correct injection timing. Once this has been achieved the input from the CMP sensor is no
longer used in any of the ECM strategies.
Electrical input to the CMP sensor is supplied via the main relay located in engine compartment
fuse box. One output is sensor earth, the other is the signal output to the ECM.
In the event of a CMP sensor signal failure the engine will crank but will not start.
Mass Air Flow/ Inlet Air Temperature (MAF/ IAT) sensor
MAF/IAt
M19 2768A
Figure 118
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The MAF/ IAT sensor is located on the engine intake air manifold, it combines the two functions
into one unit.
The MAF sensor works on the hot film principle. The MAF sensor has two sensing elements
contained within a film. One element is at ambient temperature e.g. 25 °C (77 °F) while the other
is heated to 200 °C (392 °F) above this temperature e.g. 225 °C (437 °F). As air passes through
the MAF sensor it has a cooling effect on the film. The current required to maintain the 200 °C (392
°F) differential provides a precise, although non-linear, signal of the air drawn into the engine. The
MAF sensor output is an analogue voltage proportional to the mass of the incoming air. The ECM
utilises this data, together with information from the other sensors and the fuelling maps, to
determine the correct fuel quantity to be injected into the cylinders. It is also used as a feedback
signal for the EGR system.
The IAT sensor incorporates a Negative Temperature Coefficient (NTC) thermistor in a voltage
divider circuit. As the temperature of the intake air increases, the resistance in the thermistor
decreases. As the thermistor allows more current to pass to earth, the voltage sensed at the ECM
decreases. The change in voltage is proportional to the temperature change of the intake air. From
the voltage output of the sensor, the ECM can correct the fuelling map for intake air temperature.
This correction is an important requirement because hot air contains less oxygen than cold air for
any given volume.
Inputs to the MAF sensor are a 12 volt supply from the engine compartment fuse box and an earth
path connection. There are two outputs from the MAF sensor, these are in the form of a signal and
signal return connection to the ECM. The IAT sensor utilises a 5 volt reference input from the ECM
and shares the earth path of the MAF. The output from the IAT is calculated within the ECM by
monitoring the changes in the reference voltage which supplies the IAT voltage divider circuit. The
MAF/ IAT sensor connector has gold plated terminals.
If the MAF sensor fails the ECM implements a back up strategy, which is based on engine speed.
In the event of a MAF sensor signal failure any of the following symptoms may be observed:
• Difficult starting.
• Engine stalls after starting.
• Delayed engine response.
• Emissions control inoperative.
• Idle speed control inoperative.
• Reduced engine performance.
Should the IAT sensor fail the ECM defaults to an assumed air temperature of -5 °C (23 °F).
In the event of an IAT sensor signal failure any of the following symptoms may be observed:
• Over fuelling resulting in black smoke.
• Idle speed control inoperative.
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Boost Pressure (BP) sensor
The BP sensor is located on the front side of the intake manifold and has a three pin connector. It
provides a voltage signal relative to intake manifold pressure to the ECM. The BP sensor works
on the piezo ceramic crystal principal. Piezo ceramic crystals are pressure sensitive and, in the
BP sensor, oscillate at a rate dependent on air pressure. The BP sensor produces a voltage
between 0 and 5 volts proportional to the pressure level of the air in the intake manifold. A reading
of 0 volts indicates low pressure and a reading of 5 volts indicates high pressure. The ECM uses
the signal from the BP sensor for the following functions:
• To maintain manifold boost pressure.
• To reduce exhaust smoke emissions while driving at high altitude.
• Control of the EGR system.
ECM supplies the BP sensor with a 5 volt power supply. The output from the BP sensor is
measured at the ECM. The earth path is supplied via the ECM.
In the event of a BP sensor signal failure any of the following symptoms may be observed:
• Altitude compensation inoperative (engine will produce black smoke).
• Active boost control inoperative.
• The ECM assumes a default pressure of 0.9 bar (13 lbf/in2).
Vacuum control module
The Vacuum control module is used by the ECM to control the variable nozzle turbine (VNT) within
the turbocharger unit.
The variable nozzle turbine improves turbine boost pressure by opening and closing internal
vanes. The system uses signals from the boost pressure sensor, road speed signal and engine
load to calculate a 'setpoint' boost pressure from an internal software 'map'. This in turn provides
an angle for the vanes to be set to (between open and closed) to vary the boost pressure.
Variable nozzle turbine
The variable nozzle turbine makes it possible to vary the exhaust gas flow of the turbine by varying
the angle that the guide vanes are set at. With the guide vanes in a closed position the exhaust
gas flow is reduced and the gas flow to the turbine wheel is increased. This results in an increase
in boost pressure.
The boost pressure sensor provides a feed back a signal relative to inlet manifold pressure to the
ECM. The ECM also calculates engine load and uses this along with the boost pressure sensor
input to send a signal (PWM) to the vacuum control modlue to determine the amount of vacuum
supplied to the vacuum control cell. The amount of vacuum operates between 0 mBar to 640 mBar
depression (640 mBar with the vanes fully closed-maximum boost).
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Engine Coolant Temperature (ECT) sensor
ECT
M19 2773A
Figure 119
The ECT sensor is located in the cylinder head at the front of the engine. It provides the ECM with
engine coolant temperature information. The ECM uses this ECT information for the following
functions:
• Fuelling calculations.
• Temperature gauge.
• To limit engine operation if coolant temperature is too high.
• Cooling fan operation.
• Glow plug operating time.
The ECM ECT sensor circuit consists of an internal voltage divider circuit incorporating an external
negative temperature coefficient thermistor. As temperature rises, the resistance in the thermistor
decreases, as temperature decreases, the resistance in the sensor increases. The output of the
sensor is the change in voltage as the thermistor allows more current to pass to earth according
to the temperature of the coolant. The ECM compares the signal voltage to stored values and
compensates fuel delivery to ensure optimum driveability at all times. The engine will require more
fuel when it is cold to overcome fuel condensing onto the cold metal surfaces inside the
combustion chamber. To achieve a richer air/fuel ratio the ECM extends the injector opening time.
As the engine warms up the air/fuel ratio is leaned off.
The inputs and outputs for the ECT are a reference voltage and an earth return circuit, both
provided by the ECM. The ECT signal is measured at the ECM.
In the event of an ECT sensor signal failure any of the following symptoms may be observed:
• Difficult cold start.
• Difficult hot start.
• Driveability concerns.
• Instrument pack temperature warning illuminated.
• Temperature gauge reading does not accurately represent the coolant temperature.
In the event of ECT signal failure the ECM applies a default value of 80 °C (176 °F) coolant
temperature for fuelling purposes. The ECM will also run the cooling fan when the ignition is
switched on to protect the engine from overheating.
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Exhaust Gas Recirculation (EGR) modulator
EGR
Figure 120
The EGR modulator is located on the front of the engine at the side of the starter motor. The EGR
modulator is a solenoid operated valve which regulates the vacuum source to the EGR valve,
causing it to open or close. The ECM utilises the EGR modulator to control the amount of exhaust
gas being recirculated in order to reduce exhaust emissions and combustion noise. EGR is
enabled when the engine is at normal operating temperature and under cruising conditions.
The EGR modulator receives battery voltage from the main relay in the engine compartment
fusebox. The ECM completes the earth path to the solenoid winding. The ECM controls the EGR
valve operation using a PWM signal. The duty cycle of the solenoid determines the amount of
vacuum supplied to the EGR valve and, therefore, the volume of exhaust gas allowed to enter the
cylinders.
In the event of an EGR modulator failure the EGR system will become inoperative.
Brake switch
Brake switch
M19 2826A
Figure 121
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The brake switch is located on the pedal box assembly, it is a Hall effect switch which detects the
position of the brake pedal, and therefore when the driver has applied the brakes. The ECM uses
the signal from the brake switch for the following:
• To limit fuelling during braking.
• To inhibit/ cancel cruise control if the brakes are applied.
The brake switch includes two separate circuits, one normally open and one normally closed,
connecting to earth. The two circuits are referred to as main brake and brake test.
Brake switch outputs
Switch condition
Brake not pressed
Brake pressed
Brake test circuit
Open circuit
Battery positive
Main brake circuit
Earth
6 – 8V
In the event of a brake switch failure any of the following symptoms may be observed:
• Cruise control will be inactive.
• Increased fuel consumption.
Clutch switch
Clutch switch
Figure 122
The clutch switch is a Hall effect device and is located on the pedal box assembly. The clutch
switch is activated when the clutch pedal is operated. The ECM uses the signal from the clutch
switch for the following functions:
• To provide surge damping during gear changes.
• To inhibit / cancel cruise control if the clutch pedal is pressed.
Surge damping stops engine speed rising dramatically during gear changes. Surge damping
assists driveability in the following ways:
• Smoother gear changes.
• Greater exhaust gas emission control.
• Improved fuel consumption.
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The clutch switch receives a 12 volts reference voltage from the ECM. With the clutch pedal in the
rest position the switch is connected to earth. When the clutch pedal is pressed the ECM receives
a 12 volt signal.
In the event of a clutch pedal switch failure any of the following symptoms may be observed:
• Surge damping will be inactive
• Cruise control will be inactive
Main relay
The main relay is located in the engine compartment fusebox. The relay controls the voltage
supplies to the main peripheral components of the system under the control of the ECM. The ECM
has a feed which allows it to become active when it receives an input from the ignition switch
position II (ignition on). The ECM will then energise the main relay.
The main relay is a standard normally open 4 pin relay.
The main relay contact supplies battery voltage to the following components:
• ECM
• MAF/ IAT sensor
• CMP sensor
• Fuel pressure regulator
• EGR modulator
• Glow plug relay
Voltage input to the relay winding and the contacts comes from the vehicle battery. When the main
relay is energised, the switching contact closes and power is supplied to various components on
the vehicle.
The earth path for the main relay winding is supplied by the ECM. When the earth path is
completed, the main relay energises.
In the event of a main relay failure any of the following symptoms may be observed:
• Engine will crank but not start
• The engine will stop if the relay fails
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Glow plug relay and glow plugs
Glow plug relay
M19 2769
Figure 123
The glow plug relay is located next to the ECM in the 'E' box. The ECM controls all glow plug
operations via the glow plug relay. The glow plug warning lamp is controlled by the ECM from
information received from the glow plug relay.
The 4 glow plugs are located in the cylinder head on the inlet side. The glow plugs form a vital part
of the engine starting strategy. The glow plugs heat the air inside the cylinder during cold starts to
assist combustion. The use of glow plugs helps to reduce the amount of extra fuel required on start
up, the main cause of black smoke. It also requires less injection advance, which reduces engine
noise, particularly when idling with a cold engine.
The main part of the glow plug is a tubular heating element that protrudes into the combustion
chamber of the engine. The heating element contains a spiral filament encased in magnesium
oxide powder. At the tip of the tubular heating element is the heater coil. Behind the heater coil,
and connected in series, is a control coil. The control coil regulates the heater coil to ensure that
it does not overheat.
Pre-heat is the length of time the glow plugs operate prior to engine cranking. The ECM controls
the pre-heat time of the glow plugs based on battery voltage and coolant temperature information.
Post-heat is the length of time the glow plugs operate after the engine starts. The ECM controls
the post-heat time based on ECT information. If the ECT fails, the ECM will operate pre-heat and
post-heat time strategies with default values from its memory. The engine will be difficult to start.
The glow plug relay is supplied with power directly from the vehicle battery, an earth connection
directly to the vehicle body from the glow plug relay is used. The glow plug relay also receives a
voltage signal from the main relay to indicate ignition switch operation. Input information relating
to engine temperature and time base calculations comes from the ECM. The glow plug relay is
able to process this information and then supply output control to the glow plugs in the engine.
In the event of a glow plug failure any of the following symptoms may be observed:
• Difficult starting.
• Excessive smoke emissions after engine start.
The glow plug relay is not able to generate fault codes.
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Common Rail (CR) fuel injection
The CR system is modular in design and is made up of the following components:
• ECM.
• Primary LP fuel pump.
• Secondary LP fuel pump.
• Fuel filter.
• LP fuel sensor.
• HP fuel pump.
• Fuel rail.
• Fuel rail pressure sensor.
• Four electronic injectors.
• Fuel pressure regulator valve.
The fuel rail is fed with pressurised fuel from the HP fuel pump and acts as an accumulator. The
fuel is delivered from this intermediate accumulator to the injectors via short, HP fuel pipes. The
volume of the fuel rail damps fluctuations in pressure caused by the HP fuel pump delivery and
injector operation. The fuel pressure sensor is screwed into the end of the fuel rail and sends a
voltage signal corresponding to rail pressure to the ECM.
The advantages of a CR system are as follows:
• Fuel pressure can be maintained regardless of injection duration and engine speed.
• Reduced smoke emission through more efficient atomisation due to higher injector pressures.
• Fuel pressure can be optimised to produce better idle characteristics, and reduced operating
noise.
• Greater control of the starting and finishing point of injection, thereby reducing fuel
consumption and smoke emissions.
With the CR injection system it is possible to determine injection pressure and injection volume for
a wide variety of operating conditions. With this flexibility the CR system can be utilised by the
ECM to provide the following benefits:
• Pilot fuel injection.
• Smoke limitation.
• Active surge damping.
Fuel delivery – High Pressure (HP) side
The HP fuel pump supplies fuel to the fuel rail. The pump is directly driven by the engine and is
located at the front of the engine block. Fuel rail pressure is variable to allow for fuelling strategies
such as noise limitation and surge control. The maximum fuel pressure is 1300 bar (18850 lbf/in2).
Fuel pressure is controlled by the ECM via the fuel pressure regulator valve located at the rear of
the HP fuel pump. The ECM uses the output signal from the fuel rail pressure sensor, mounted on
the end of the fuel rail, to maintain the optimum fuel pressure for the current conditions. The fuel
pressure regulator reduces pressure by diverting fuel from the HP output back to the fuel tank.
The minimum operating pressures are 200 bar (2900 lbf/in2) during cranking and 300 bar (4350
lbf/in2) during idle, failure to reach these pressures will result in a non start situation, stalling or
erratic idle.
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Fuel pressure regulator valve
The pressure regulator valve is mounted on the high-pressure pump and controls the fuel pressure
within the fuel rail. It is an electrically operated solenoid valve controlled by the ECM with only two
states, open and closed. When de-energised, the valve is opened by a spring, diverting fuel to the
return line. This decreases the fuel pressure in the fuel rail. In this state fuel rail pressure is
approximately 100 bar (1450 lbf/in2). When energised, the valve is closed, allowing maximum fuel
pressure in the fuel rail. This pressure can reach approximately 1300 bar (18,854 lbf/in2). The ECM
controls the fuel rail pressure by operating the pressure regulator valve with a pulse width
modulated signal. The longer the opening time (duty cycle) of the valve, the lower the pressure in
the fuel rail. The shorter the opening time (duty cycle) of the valve, the higher the pressure in the
fuel rail.
The pressure regulator receives a PWM signal of 0-12 volts from the ECM. ECM actuation of the
pressure regulator is determined by the following:
• Fuel rail pressure.
• Engine load.
• Accelerator pedal position.
• Engine temperature.
• Engine speed.
In the event of a pressure regulator failure, any of the following symptoms may be observed:
• Engine will not start.
• Severe loss of power.
• Engine stalls.
Electronic fuel injector
There are four electronic fuel injectors (one for each cylinder), each located in the centre of a
cylinder's four valves. The electronic fuel injectors are supplied with fuel from the fuel rail and
deliver finely atomised fuel directly into the combustion chambers. Each injector is controlled
individually by the ECM according to the firing order. The injectors are provided with an 80volt
power supply from the capacitor within the ECM. The ECM provides the earth path for the
electronic fuel injectors. By using an injection/ timing map within its memory, the ECM is able to
determine precise pilot and main injection timing for each cylinder.
If battery voltage falls to between 6 and 9 volts, the electronic fuel injector operation is restricted,
affecting the engine maximum speed range and idle speed.
Input to the electronic fuel injectors takes the form of electrical pulses (0 - 12V) from the ECM. The
length of each pulse determines the amount of fuel injected.
In the event of a fuel injector failure, any of the following symptoms may be observed:
• Engine misfire.
• Idle faults.
• Reduced engine performance.
• Reduced fuel economy.
• Difficult cold start.
• Difficult hot start.
• Increased smoke emissions.
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Fuel rail pressure sensor
Pressure sensor
M19 2763
Figure 124
The fuel rail pressure sensor is located on the end of the fuel rail. A diaphragm located within the
sensor is in contact with the pressurised fuel. An electronic resistive element, attached to the
diaphragm, distorts as the diaphragm changes in shape due to the pressure exerted by the fuel.
The resistance values are converted into an analogue voltage within the pressure sensor and this
signal is processed by the ECM. The ECM compares the signal to stored values to calculate
current fuel pressure.
The fuel rail pressure sensor consists of the following components:
• Sensor housing with electrical connection
• Printed circuit board with electrical evaluation switch
• Diaphragm with integrated sensor element
Electrical input to the fuel rail pressure sensor is a 5 volts supply from the ECM. Output is an
analogue voltage between 0.5 - 4.5 volts.
In the event of a fuel rail pressure sensor failure any of the following symptoms may be observed:
• Engine will not start
• Severe loss of power
• Engine stalls
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Cruise control
Cruise control
Introduction
Cruise control is a system which attempts to maintain the speed of a vehicle at a defined setting
by automatically controlling the throttle angle. It was designed to make driving long distances on
motorways less stressful by taking over throttle control from the driver. Cruise control is available
as an option on KV6/JATCO and M47R/JATCO derivatives of Freelander 2001.
An ECU is at the centre of the KV6 cruise control system, monitoring various inputs and changing
various outputs to maintain the set speed. Cruise control is a good example of a closed loop
control system, with a number of safety inputs which disengage the system for practical reasons.
For example, when braking it would be hazardous to continue to allow the cruise control system
to attempt to maintain the speed of the vehicle.
Differences exist between the components that make up the cruise control petrol system and the
diesel system, but the driver interface and system operation are basically the same.
KV6 cruise control
The KV6 cruise control system is a Hella electro-pneumatic system which, through the controlling
ECU, adjusts the throttle angle to suit the set speed. The system uses a vacuum pump to control
a pneumatic actuator, which adjusts the throttle angle via a connecting rod. The vacuum pump
unit also contains the pressure control valve (regulation valve) and the pressure release valve
(dump valve).
Cruise control block diagram
Figure 125
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When the vehicle is in cruise control mode and is travelling at the set speed, the cruise ECU is in
control of the speed of the vehicle. The cruise control warning lamp located in the instrument pack
will be illuminated to inform the driver that cruise control is active. The ECU will have energised
the vacuum pump, which, in turn, will have moved the throttle actuator diaphragm to a position
which corresponds to the set speed required. The ECU monitors the affect on the speed of the
vehicle via the wheel speed signal from the ABS ECU. To maintain the speed, the ECU will
continually monitor the wheel speed signal. Varying driving conditions such as gradients and wind
resistance can alter the speed of the vehicle. The ECU will control the actuation of the vacuum
pump and of the regulator solenoid valve, to increase and decrease the throttle angle, as required.
Cruise control operation
To enter cruise control, the driver needs first to press the cruise master switch located on the
dashboard. The cruise system is operative only within the range 28 - 125 mph (40 - 200 km/h) and
the driver must be aware of this. When the required cruising speed is reached, using the
accelerator pedal, the Set + button on the steering wheel should be pressed. The vehicle will
attempt to maintain the current speed as long as the ECU receives no inputs signalling application
of the brakes, clutch or throttle.
If the brake pedal or the Res(ume) switch are activated, cruise control will be suspended. On
cruise suspension, the set cruise speed will be stored in the cruise ECU. The driver will have
complete control of the vehicle and will have to apply throttle to prevent the vehicle from coasting
to a stop. Cruise control is restored by pressing the Res switch again and the system will return
the vehicle to the speed stored in the cruise control ECU. If the cruise ECU recognises a fault with
the system or any of its associated components it will suspend the operation of cruise control
indefinitely i.e. Until the fault is rectified.
Accelerating
There are three ways to accelerate the vehicle when cruise control is active:
Cancelling cruise control
Cruise control can be cancelled by pressing the cruise master switch on the dashboard or by
turning off the ignition. In both of these cases the cruise speed stored in the cruise control ECU
memory will be lost. On reactivation of the cruise control system a new cruise speed will have to
be set by pressing the Set+ speed at the appropriate speed.
Components and their functions
The following list outlines the location and functionality of cruise control components:
Master control switch
Located on the dashboard, this mechanically latching switch is placed in series between the
ignition feed and the cruise control ECU. It also provides a feed which electrically enables the
cruise control interface unit. This switch controls the electrical supply to the system and acts as an
isolator or 'On'/'Off' switch. When switched on, the switch is illuminated, indicating that cruise
control is available.
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Cruise control ECU
Located on a bracket under the right hand front seat the cruise ECU unit controls the system,
based on a number of inputs from around the vehicle.
Cruise control electronic control unit
Figure 126
Cruise control interface unit
Located on a bracket under the right hand front seat, and attached to the same bracket as the
cruise ECU. This unit controls the enabling of the actuator power feed to the cruise ECU based on
inputs from the ECM and the brake switch.
Wheel speed sensor
Wheel speed is supplied to the cruise control system via the ABS ECU from the wheel speed
sensors. The ABS wheel speed sensors are passive type sensors operating on inductive
principles. The ABS ECU outputs a 0-12 volt square wave to the cruise control ECU which is
proportional to the road speed and provides 8,000 pulses per mile.
If the wheel speed signal is not present then the supply to the vacuum pump will not be activated
and cruise will not engage. The road speed signal is an average of all working wheel speed
sensors. If one to three of the wheel speed sensors fail the cruise system can still function within
its range, operating from the remaining sensor signal. However in this situation the speed
accuracy of the system may be impaired.
If all four sensors fail, and the speed input to the cruise ECU is not present, cruise will not be
operational.
'Set +' switch
Located on the steering wheel, this non latching push switch is used to set the cruise control speed
by pressing once and to increase the set cruising speed by pressing and holding until the desired
speed is reached. 1mph increments are achieved by pressing for less than 0.5 seconds.
'Res -'switch
Located on the steering wheel below the Set + switch, this non latching switch is used to return to
the stored cruise speed after cruise has been suspended. It is also used to suspend cruise control
by pressing it once when cruise control is active.
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Brake pedal position sensor
Outputs from the brake pedal position sensor are supplied to the interface ECU and the cruise
control ECU to enable the system to detect when the brakes are applied. The brake pedal position
sensor is a Hall effect sensor that produces two outputs. One output is supplied to both the
interface ECU and the cruise control ECU; the second output is only supplied to the interface ECU.
Both outputs should be 0 to 2 volts while the brake pedal is released, then increase to between 8
and battery volts when the brake pedal is pressed.
The brake light input from the hall switch is a normally low voltage into pin 5 of the cruise ECU, but
when the brake pedal is pressed, this input is pulled HIGH. On receipt of a HIGH brake light signal,
the ECU cancels cruise and removes the supply to the pump. The ECU also de-activates a
solenoid on the vacuum pump which dumps all the air currently stored within the actuator.
Circuit diagram
Figure 127
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Mechanical brake switch
An output from the brake pedal switch is supplied to the vacuum pump assembly to ensure cruise
control disengages when the brakes are applied, even if the vacuum pump assembly remains
active. The dump valve in the vacuum pump assembly is earthed via the brake lamps and
energised closed while cruise control is active. The brake pedal switch is open while the brake
pedal is released. When the brakes are applied, the brake pedal switch closes and connects a
power feed to the brake lamps circuit, and thus to the earth side of the dump valve. This ensures
the dump valve is de-energised, which allows it to open and release the vacuum from the vacuum
actuator.
Integrated vacuum pump
The vacuum pump is located in the LH front corner of the engine compartment, on mounting
rubbers attached to the front of the battery box. Integrated with the pump unit are the regulator
solenoid valve and the release/dump solenoid valve. Connecting hoses link the outlets of the
control valve and the dump valve to the inlet side of the vacuum pump, at a vacuum actuator
connection. A further connecting hose links the inlet side of the control valve to the outlet side of
the vacuum pump at a common vent. A second vent is provided for the inlet to the dump valve. A
non return valve between the vacuum pump and the vacuum actuator connection prevents the
reverse flow of air through the vacuum pump. An electrical connector on the underside of the valve
housing connects the vacuum pump assembly to the cruise control ECU and the brake pedal
switch via the vehicle wiring.
The cruise ECU controls the electrical inputs to the vacuum pump and motor, and to the solenoid
valves. Switching 'on' and 'off' of the vacuum pump and the control of the vacuum release dump
solenoid valve are governed by the cruise ECU. The cruise ECU controls the throttle actuator and
maintains the throttle in the correct position to match the cruise speed selected. It does this by
continuously switching the vacuum motor 'on' and 'off', and opening and closing the release/dump
solenoid valve. The vacuum release/dump control solenoid is opened fully when cruise is
suspended and the power to the vacuum pump and motor is switched off. Therefore, the vacuum
acting on the throttle actuator is released. The instrument pack taps off the supply from the cruise
ECU to the pump and uses it to illuminate the cruise active indicators. This line is also fed to the
automatic transmission control unit (ATCU) and enables selection of the cruise control shift map.
Vacuum pump
Figure 128
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Pneumatic actuator
The vacuum actuator translates pneumatic pressure changes into axial movement to operate the
throttle. The actuator is installed in a mounting bracket attached to the throttle body.
A diaphragm installed in a chamber is connected to the vacuum pump assembly on one side and
vented to atmosphere on the other. An actuating rod connects the diaphragm to the throttle linkage
on the throttle body. When cruise control is engaged, the vacuum pump assembly reduces the
pressure on one side of the diaphragm and the diaphragm moves the actuating rod to operate the
throttle. The operating range of the vacuum actuator is from 0 to 88 ± 4 % of throttle opening. This
ensures there is sufficient range to induce normal down gear changes, but prevents kickdown.
The throttle linkage allows the vacuum actuator to operate the throttle without moving the
accelerator pedal, and also allows the accelerator pedal to override the vacuum actuator, to
increase throttle opening, when the driver wants to accelerate the vehicle above the set speed.
Throttle actuator
Figure 129
Automatic transmission
When the gear selector lever is in park, neutral or reverse, cruise is inoperative. The ATCU
transmits the selected gear onto the CAN bus system. The engine management system receives
the CAN signal and only enables cruise, via the cruise interface unit, if the appropriate gear has
been selected.
There is also a link to the automatic transmission control unit which informs the ATCU that cruise
has been activated and the correct gear shift map can be selected.
Cruise control instrument lamp
When cruise is active, the yellow warning lamp is illuminated on the instrument panel to inform the
driver that cruise control is active.
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Suspension of petrol cruise control
The following are actions and conditions which will cancel the operation of petrol cruise control but
retain the set speed in the cruise ECU memory:
• Operation of the RES/SUS switch when cruise is active
• Brake switch operation
• Appropriate forward gear not selected
• Engine speed out of range (0–6550 rpm)
• Road speed out of range 28-125mph
• Acceleration limit exceeded (approx 5m/s2)
• Traction control active
• Vehicle speed drops below 75% of set speed
M47R diesel cruise control
The cruise control system on KV6 is a stand alone system with its own ECU and interface unit and
it controls the throttle angle directly. On the M47R engine the cruise control system is integrated
into the Bosch engine management system and fuel delivery is controlled via the drive by wire
system. There is no vacuum pump or throttle actuator.
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Component location
Figure 130
1.Master switch
2.Warning lamp (all except NAS)
3.Warning lamp (NAS only)
4.Steering wheel switches
5.Interface ECU
Software within the engine management system, working in conjunction with associated
components around the vehicle, directly controls the fuel injector pulse width. This control ensures
the right amount of fuel is delivered to maintain the vehicle at the set speed programmed by the
driver.
Other components of the M47RR cruise control system are the cruise interface unit, and inputs
from around the vehicle i.e. brake switch, steering wheel switches, the master switch, road speed
signal and a signal from the automatic gearbox.
From a customer/driver perspective the activation and adjustment of the diesel cruise control
system is the same as that of the KV6 control system.
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M47R control diagram
Figure 131
M47R cruise interface unit
This is an ECU which listens on the CAN-Bus system and converts driver inputs from the master
switch and the steering wheel switches into the digital format that is compatible with the ECM. This
serial message is termed multi-function logic (MFL) and is transmitted via a discrete link between
the interface unit and the ECM. The interface unit also provides a 12 volt hard wired signal to the
instrument pack and the ATCU when cruise is active.
A series of pulses between 0 and 12 volts is transmitted from the interface unit to the ECM. The
ECM can convert these pulses into a message which determines the status of the cruise switches.
This signal is sent continually to the ECM and if it is not present cruise will be suspended by the
ECM. The ECM will store an MFL fault in this type of failure.
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M47R cruise interface unit
Figure 132
Engine control module
The signal from the interface unit to the ECM will contain information supplied by the steering
switches. The ECM monitors various other inputs from around the vehicle and can calculate a
fuelling strategy based on the inputs to maintain the required speed. The ECM also delivers a
signal to the ATCU, via the CAN system, which is equivalent to the throttle angle (virtual throttle
angle). This signal is used by the automatic transmission control unit to control gear shifting to suit
requirements.
The brake switch output and the wheel speed signal are fed into the ECM. When circumstances
arise requiring suspension of cruise, the ECM sends a signal to the interface unit, via CAN, that
it is suspending cruise and the interface unit stops the cruise active signal to the ATCU and the
instrument pack.
The road speed signal is sent by the ABS ECU to the engine management system via a CAN link.
The signal is an average of all working wheel speed sensors.
This system suspends and cancels cruise in the same circumstances as the KV6 system. The
M47R diesel cruise control system will also cancel cruise if the vehicle speed overshoots the
stored speed by over 16 km/h for more than 30 seconds. This can be as a result of the vehicle
going down hill for long periods or by the driver overriding cruise using the accelerator pedal.
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Figure 133
CAN functions
The CAN bus is a serial communications data bus, consisting of two wires twisted together, that
allows the high speed exchange of digital messages between control units. The following CAN
messages are used for control of the cruise control system:
• Cruise control status, from the ECM. To advise the interface ECU if the ECM cruise control
mode is active or inactive. Also used by the instrument pack to operate the cruise control
warning lamp.
• Road speed, produced by the ABS modulator from ABS sensor inputs. Used by the ECM for
monitoring vehicle speed.
• 'Virtual' accelerator pedal position, calculated by the ECM from the amount of fuel used to
maintain the set speed. Used by the EAT ECU for gear change control, in place of the input
from the accelerator pedal position sensor.
• Gear position, from the EAT ECU. Used by the ECM to ensure the vehicle is in drive for cruise
control operation.
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Suspension of diesel cruise control
The following are actions and conditions which will cancel the operation of diesel cruise control but
retain the set speed in the EMS memory:
• Operation of the RES/SUS switch when cruise is active
• Brake switch operation
• Appropriate forward gear not selected
• Road speed out of range 28-125mph
• Deceleration limit exceeded
• Traction control active
• Vehicle speed overshoots set speed by 16 k/ph for more than 30 seconds
Diagnostics and fault finding
Diagnostic is carried out using TestBook which interrogates the engine control module for faults
stored on the cruise control system. Although the interface unit is an ECU, it cannot communicate
with TestBook via the diagnostic line.
A fault with the interface unit can be detected by measuring the multi-function logic output to the
engine management system using a voltmeter. When functioning correctly, the reading will
fluctuate midway between 0 and 12 volts e.g. 6 - 8 volts. If the reading is either a constant 0 volts
or a constant 12 volts this indicates a failure inside the interface unit. An MFL fault will be stored
by the ECM. A faulty CAN harness link from the interface unit to the ECM could trigger the ECM
to store an MFL fault because the MFL signal would not be present. If the MFL signal is present
at the output from the interface unit but an MFL fault is stored by the ECM, it is logical to assume
a fault with the CAN link.
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JATCO
JATCO
General
The JATCO JF506E automatic gearbox is an electronically controlled, five speed gearbox which
incorporates software to enable the gearbox to operate as a semi-automatic 'Steptronic' gearbox.
Transmission component location
Figure 134
1.Instrument pack
2.Electronic Automatic Transmission (EAT)
ECU
3.Engine Control Module (ECM) - M47R
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4.Engine Control Module (ECM) - KV6
5.JATCO Steptronic gearbox
6.Fluid cooler
7.Selector lever assembly
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The gearbox can be operated as a conventional automatic gearbox by selecting P, R, N, D, 4, 2
or 1 on the selector lever. Moving the selector mechanism across the gate to the 'S/M' position,
sends a signal to the Electronic Automatic Transmission (EAT) ECU, also known as the Automatic
Transmission Control Unit (ATCU) and puts the gearbox into sport/manual mode.
In sport mode, the gearbox still operates as a conventional automatic transmission, but the unit
becomes more responsive to driver demands. Lower gears will be held longer and the
transmission will downshift more readily. This gives increased acceleration and improves vehicle
response.
When in sport mode, if the selector lever is moved to the + or - positions, the system will
automatically change to operate in manual mode. Manual gear changes can be performed
sequentially using the selector lever. Movement of the selector lever in the forward (+) direction
changes the gearbox up the ratios and movement in a rearward (-) direction changes the gearbox
down the ratios.
Gearbox operation is controlled by the EAT ECU and the Engine Control Module (ECM) which
communicate via a Controller Area Network (CAN) Bus. The EAT ECU receives information from
the ECM and gearbox sensors to calculate the appropriate gear ratio for the conditions and
controls solenoid valves to operate the gearbox as required.
The advantages gained with the electronically controlled gearbox are smoother gear changes,
quicker and more accurate gear change scheduling and reduced fuel consumption through
improved engine/gearbox speed matching.
Steptronic JATCO automatic gearbox
The JATCO five speed automatic gearbox is similar to conventional electronically controlled
transmissions but provides the driver with an additional manual mode feature. Manual mode
allows the driver to electronically select the five forward gear ratios and operate the gearbox as a
semi-automatic manual gearbox.
The individual gear ratios are achieved through three planetary gear sets. The components of the
planetary gear sets are driven or locked by means of four multi-plate clutches, two multi-plate
brakes, one brake band and two one-way clutch assembles. The torque is transmitted from the
gearbox to the final drive through a reduction gear.
Gearbox casing
The gearbox casing contains the input shaft transmitting the power into the drive train. The drive
train is made up of the planetary gear sets and clutches.
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Figure 135
1.Gearbox
2.Solenoid valves and valve block
3.Fluid pan
The clutches and brake bands control which elements of the planetary gear sets are engaged and
their direction of rotation, to produce the P and N selections, five forward ratios and one reverse
gear ratio. Power output is from the drivetrain through a reduction gear into a differential.
Gear Ratios
Gear
Ratio
KV6
M47R
1st
2nd
3rd
4th
5th
Reverse
Final Drive Ratio
3.474
1.948
1.247
0.854
0.685
2.714
3.66
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3.801
2.131
1.364
0.935
0.685
2.970
2.91
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Valve block and solenoid valves
The gearbox uses nine solenoid valves located on the valve block. The solenoid valves are
energised/de-energised by the EAT ECU to control the gearbox fluid flow around the gearbox to
supply clutches, brakes and brake band (gear change scheduling), fluid to the torque converter,
lubrication and cooling.
Figure 136
1.Shift solenoid valve A
2.Reduction timing solenoid valve
3.Shift solenoid valve B
4.Shift solenoid valve C
5.2-4 brake duty solenoid valve
6.2-4 brake timing solenoid valve
7.Low clutch timing solenoid valve
8.Lock-up solenoid valve
9.Line pressure duty solenoid valve
Each solenoid valve is controlled separately by the EAT ECU. All nine solenoid valves can be
classified into two types by their operating type. Three of them are duty solenoid valves and the
remaining six are on-off solenoid valves.
Each solenoid valve consists of an internal coil and needle valve. A voltage is passed through the
coil of the solenoid to actuate the needle valve. The needle valve opens and closes the fluid
pressure circuits. On-off solenoid valves close the fluid pressure circuits in response to current
flow.
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Duty solenoid valves repeatedly turn on and off in 50 Hz cycles. This opens and closes the fluid
circuits allowing a higher level of control on the circuits. For example, smooth operation of the lockup clutch in the torque converter to eliminate harsh engagement/ disengagement.
All of the solenoid valves are supplied with battery voltage and an earth path by the EAT ECU.
On/Off solenoid valves
The on/off solenoid valves are:
• Shift solenoid valve A
• Shift solenoid valve B
• Shift solenoid valve C
• Low clutch timing solenoid valve
• Reduction timing solenoid valve
• 2-4 brake timing solenoid valve.
The EAT ECU switches the on/off solenoid valves to open and close in response to vehicle speed
and throttle opening.
Shift solenoid valves A, B and C are used to engage the different gear ratios within the gearbox.
The position of these solenoid valves at any one time determines the gear selected.
Shift solenoid Valve Activation
Shift Solenoid Valve
A
B
C
X = Solenoid Valve Off
O = Solenoid Valve On
1st Gear
X
O
O
2nd Gear
O
O
X
3rd Gear
X
O
X
4th Gear
X
X
O
5th Gear
O
X
O
The reduction timing solenoid valve, low clutch timing solenoid valve and 2-4 timing solenoid valve
are used by the EAT ECU to control the timing of the gear shift changes.
These solenoid valves carry out three main functions:
• Shift timing control:For some shifts these three solenoid valves are used to assist line
pressure control or 2-4 brake pressure control.
• Line pressure cut back: When the gearbox takes up the drive there should be a high line
pressure present. The EAT ECU controls the low clutch timing solenoid valve which is related
to the vehicle speed in order to switch the fluid circuit of the line pressure to on or off therefore
controlling cut back.
• Reverse inhibition: If the vehicle exceeds 6 mph (10 km/h) and Reverse (R) is selected, the
EAT ECU switches the low clutch timing solenoid valve on. This drains the gearbox fluid from
the reverse clutch, therefore the clutch will be unable to engage.
Duty solenoid valves
The duty solenoid valves are:
• Lock-up duty solenoid valve
• Line pressure duty solenoid valve
• 2-4 duty brake solenoid valve.
The lock-up duty solenoid valve is used by the EAT ECU to control the lock-up of the torque
converter depending upon the vehicle speed and throttle position.
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The EAT ECU will actuate the lock-up solenoid valve, which operates the lock-up control valve to
direct fluid to either lock or unlock the torque converter.
The line pressure duty solenoid valve and 2-4 duty brake solenoid valve are used by the EAT ECU
to control fluid line pressure in the gearbox.
The EAT ECU calculates the line pressure by using the engine speed, vehicle speed and throttle
angle. The EAT ECU then actuates the solenoid valves accordingly to achieve the required line
pressure.
The solenoid valves can fail in the following ways:
• Open circuit
• Short circuit to 12 or 5 volts
• Short circuit to earth.
In the event of a solenoid valve failure any of the following symptoms may be observed:
• Gearbox selects fourth gear only (shift solenoid valve failure)
• Gearbox will not upshift to fourth gear (timing solenoid valve failure)
• Increased fuel consumption and emissions (lock-up solenoid valve failure)
• Gear shifts will have no torque reduction therefore gear changes will be very harsh (line
pressure duty solenoid valve failure)
• No pressure control will occur therefore gear changes from fifth gear will be very harsh (2-4
brake duty solenoid valve failure).
Torque converter
The torque converter is located inside the torque converter housing which is on the engine side of
the gearbox casing.
The torque converter acts as the coupling element between the engine and gearbox. The driven
power from the engine is transmitted hydraulically and mechanically in certain gears and
operating conditions, through the torque converter lock-up clutch to the gearbox. The torque
converter is connected to the engine by a drive plate.
The torque converter consists of an impeller, stator and turbine. The engine drives the impeller,
while the turbine drives the gearbox.
The stator is situated between the impeller and turbine on a one-way clutch. The impeller picks up
fluid and throws it out into the turbine, thereby causing it also to rotate and transmit power.
The stator redirects the fluid thrown back by the turbine so that it re-enters the impeller in the same
direction of rotation as the impeller, and at the best possible angle for efficient power gearbox.
The one-way clutch prevents the stator from moving backwards, so that this accurate redirection
of fluid can be achieved. When the engine is idling the impeller throws out very little fluid. The
turbine is not forced to turn, and the power is not transmitted to the gearbox.
As engine speed increases the impeller throws out more fluid. The turbine begins to turn and picks
up speed as the engine speed rises. As the speed of the turbine increases the fluid is thrown
against the back of the stator, causing it to turn in the same direction.
When turbine speed approaches impeller speed, centrifugal force in both units is almost equal and
all three components move at nearly the same rate. This is called the 'coupling point'.
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The torque multiplication or drive ratio varies until a one to one coupling point is reached.
To achieve the power required to climb a hill, the driver depresses the accelerator pedal and the
torque converter reacts by increasing the torque multiplication.
When driving on a flat road at cruising speed, the power required is not as great and therefore, the
torque converter stays at one to one.
Figure 137
1.To engine
2.Torque converter cover welded to the
impeller
3.Lock-up clutch
4.Turbine
5.One-way clutch
6.Stator
7.Impeller
8.To gearbox
Torque converter lock-up mechanism
In a torque converter there is always a certain amount of slip between the impeller and turbine.
This will contribute to a reduction in fuel economy especially during high speed cruising.
This is eliminated by the torque converter lock-up mechanism. The lock-up mechanism is attached
to the turbine and controls a lock-up clutch which is integral with the torque converter.
The lock-up mechanism comprises a lock-up solenoid valve, a lock-up control valve and a lock-up
clutch.
The lock-up control is provided by the EAT ECU which operates the lock-up solenoid valve. The
EAT ECU controls lock-up clutch engagement and release according to the lock-up schedule
programmed into the ECU and the vehicle speed and throttle angle.
The lock-up mechanism operates with the gearbox in 'D' (normal mode 4th and 5th gears) and in
manual 4th and 5th gears. In an emergency condition when high fluid temperatures are reached,
the EAT ECU can also operate the lock-up mechanism in 2nd and 3rd gears to help reduce fluid
temperatures.
In addition to the lock and unlock conditions, the lock-up control can also initiate smooth lock-up,
coast lock-up and lock-up prohibition control.
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Smooth lock-up minimises lock-up shock by smoothly and slowly engaging the lock-up clutch.
Coast lock-up control maintains the lock-up condition after the throttle pedal has been released in
the lock-up range at certain high speed driving. This prevents the lock-up control switching
between the locked and unlocked condition caused by repeated on-off use of the throttle pedal.
Lock-up prohibition control prevents clutch lock-up within the range if the fluid temperature is
below 40°C (104°F). This promotes faster warm-up of the gearbox fluid. This strategy is also used
by the EAT ECU to prevent lock-up in 1st gear, park, reverse and neutral ranges.
Unlock condition
The unlock release pressure is supplied via the control valve to the lock-up clutch. The pressure
forces the clutch mechanism away from the torque converter and moves the lock-up mechanism
into the unlock condition. The torque converter pressure is decayed to the drain port, removing the
applied pressure from the torque converter, allowing the clutch mechanism to move.
2
3
1
12
11
4
10
5
6
9
7
9
M44 1623
Figure 138
1.Impeller
2.Turbine
3.Lock-up clutch
4.Release pressure
5.Lock-up control valve
6.Drain port
7.Torque converter pressure
8.Lock-up solenoid
9.Fluid cooler
10.Torque converter applied pressure
11.Lubrication
12.Input shaft
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Lock-up condition
The EAT ECU operates the lock-up solenoid, which in turn supplies pilot pressure to the control
valve. The control valve moves under the influence of the pilot pressure, blocking the release
pressure feed to the lock-up clutch and re-directing it to the other side of the clutch mechanism.
With the release pressure removed, the lock-up clutch moves and engages with the torque
converter, moving the lock-up mechanism into the locked condition.
2
3
1
11
10
9
4
7
5
8
6
M44 1624
Figure 139
1.Impeller
2.Turbine
3.Lock-up clutch
4.Lock-up control valve
5.Torque converter pressure
6.Lock-up solenoid
7.Pilot pressure
8.Fluid cooler
9.Torque converter applied pressure
10.Lubrication
11.Input shaft
Smooth lock-up
Smooth lock-up occurs as the mechanism moves from the unlock to the locked condition. Torque
converter release pressure is lowered gradually preventing a sudden lock-up clutch engagement,
reducing lock-up shock.
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The lock-up solenoid is a driven duty solenoid operating at 50Hz. The lock-up control valve has a
pressure regulation device which reacts to torque converter release pressure and solenoid pilot
pressure.
As the solenoid is operated, the pilot pressure is gradually applied to the control valve. This moves
the valve, partially exposing the release pressure to a drain port.
The control valve is moved against an opposing spring by the increasing pilot pressure. The
release pressure is decayed proportionally in response to the increasing pilot pressure allowing
the clutch to smoothly engage with the torque converter.
Fluid cooling
Fluid cooling is performed by a dedicated fluid cooler for the gearbox located on a bracket at the
front of the gearbox.
The fluid cooler comprises cores which allow fluid to flow across from one side of the cooler to the
other. Each core is surrounded by a water jacket which allows engine coolant to flow around the
cooler.
The cooler is connected to the gearbox by metal pipes and flexible hoses. The engine coolant is
connected from the heater matrix to the cooler and from the cooler to the thermostat housing with
coolant hoses.
The gearbox fluid flows from the gearbox to the upper connection on the fluid cooler. The fluid then
flows through the cores in the cooler which are surrounded by engine coolant which cools the
gearbox fluid. The fluid exits the fluid cooler via the lower connection and is returned to the
gearbox.
The engine coolant flows from the engine oil cooler into the upper coolant connection on the fluid
cooler. The coolant exits the cooler via the lower connection and flows to the thermostat housing.
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Blast air cooler
Figure 140
1.Gearbox fluid feed pipe
2.Gearbox fluid return pipe
3.Engine coolant feed hose
4.Engine coolant return hose
5.Bracket
6.Fluid cooler
Sensors
The EAT ECU sets correct gear change scheduling using three speed signal inputs: intermediate
speed, turbine speed and vehicle speed in conjunction with a throttle position signal from the ECM.
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Intermediate speed sensor
Figure 141
The intermediate speed sensor is located within the gearbox. The EAT ECU uses this sensor to
ensure correct gear engagement and to monitor the amount of slip within the gearbox.
The EAT ECU calculates the slip within the gearbox by comparing the difference between the
inputs from the intermediate speed sensor and the turbine speed sensor.
The intermediate speed sensor detects the output gear rotation speed and sends an electrical
output to pin 51 of the EAT ECU which also supplies an earth path for the sensor on ECU pin 20.
The sensor is an inductive sensor that produces a sinusoidal output at a frequency of 54 pulses
per revolution of the output gear.
The intermediate speed sensor can fail in the following ways: Sensor open circuit Short circuit to
12 or 5 volts Short circuit to earth. The EAT ECU will detect sensor failure if the vehicle speed
exceeds 25 mph (40 km/h) and the sensor output is equivalent to less than 600 rev/min for two
seconds.
In the event of an intermediate speed sensor signal failure any of the following symptoms may be
observed:
• Upshift to 5th gear inoperative
• Torque reduction request from the EAT ECU to the ECM inoperative.
A failure of the sensor will generate a 'P' code which can be retrieved using TestBook or any
Keyword 2000 diagnostic tool.
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Turbine speed sensor
Figure 142
The turbine speed sensor is located within the gearbox and is used by the EAT ECU to monitor
the input shaft speed. The EAT ECU uses this sensor to ensure the correct gear ratio is selected
and to ensure that there is not excessive slip within the gearbox drive train.
The turbine speed sensor detects the input shaft speed (turbine speed) and sends an electrical
output to pin 24 of the EAT ECU which also supplies an earth path for the sensor on ECU pin 20.
The sensor is an inductive sensor that produces a sinusoidal output at a frequency of 36 pulses
per revolution of the input shaft.
The turbine speed sensor can fail in the following ways:
• Sensor open circuit
• Short circuit to 12 or 5 volts
• Short circuit to earth.
The EAT ECU will detect sensor failure if the vehicle speed exceeds 25 mph (40 km/h) and the
engine speed is above 1300 rev/min, but the turbine speed is below 600 rev/min for two seconds.
In the event of a turbine speed sensor signal failure any of the following symptoms may be
observed:
• Upshift to 5th gear inoperative
• Torque reduction request from the EAT ECU to the ECM inoperative.
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A failure of the sensor will generate a 'P' code which can be retrieved using TestBook or any
Keyword 2000 diagnostic tool.
Vehicle speed sensor
Figure 143
The vehicle speed sensor is located within the gearbox. The EAT ECU uses this sensor to monitor
the rotational speed of the parking gear and calculate this reading into a vehicle speed. The EAT
ECU also monitors the vehicle speed using a signal from the ABS ECU.
The vehicle speed sensor detects the parking gear rotation speed and sends an electrical output
to pin 5 of the EAT ECU which also provides an earth path for the sensor.
The sensor is an inductive sensor that produces a sinusoidal output at a frequency of 18 pulses
per revolution of the parking gear.
The EAT ECU uses the signal to calculate the following:
• Amount of engine torque reduction required during gear changes
• Notify the EAT ECU when the vehicle is stationary, for creep control.
The vehicle speed sensor can fail the following ways:
• Sensor open circuit
• Sensor short circuit to 12 or 5 volts
• Sensor short circuit to earth.
The EAT ECU will detect sensor failure if the ABS ECU speed signal is more than 25 mph (40 km/
h) but the vehicle speed sensor reading is less than 3 mph (5 km/h) for more than two seconds.
In the event of a vehicle speed sensor signal failure any of the following symptoms may be
observed: Upshift to 5th gear inoperative Torque reduction request from the EAT ECU to the ECM
inoperative.
If a failure of the vehicle speed sensor occurs and the ABS ECU speed signal is functional, the
EAT ECU will control gear shifting using the ABS ECU signal.
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If both the vehicle speed sensor and the ABS ECU speed signals fail, the EAT ECU will lock the
gearbox in fourth gear (fail-safe mode) and inhibit torque converter lock-up control.
Fluid temperature sensor
Figure 144
The fluid temperature sensor is located within the gearbox on the valve block. The EAT ECU uses
this sensor to monitor the gearbox fluid temperature.
When the fluid is cold, the EAT ECU changes gear at higher engine speeds to promote faster fluid
warm-up. If the fluid temperature becomes too high, the EAT ECU transmits a cooling request on
the CAN link to the ECM to operate the cooling fans.
The fluid temperature sensor has an electrical output to pin 39 of the EAT ECU which also
provides an earth path for the sensor.
The fluid temperature sensor is a negative temperature coefficient sensor. As the temperature
rises, the resistance in the sensor decreases. As temperature decreases, the resistance in the
sensor increases and the output voltage to the EAT ECU changes in proportion.
The output voltage from the sensor is in the range of 0 - 2.5 Volts with the lower voltage
representing the highest temperature.
The change in resistance is proportional to the temperature of the gearbox fluid. From the
resistance of the sensor, the EAT ECU calculates the temperature of the gearbox fluid. Should the
fluid temperature sensor fail the EAT ECU uses the last recorded EAT ECU value as a default
value.
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Fluid temperature sensor resistance values
Temperature °C (°F)
-40 (-40)
-20 (-4)
0 (32)
20 (68)
40 (104)
60 (140)
80 (176)
100 (212)
120 (248)
140 (284)
Resistance kOhms Ω
54.90
16.70
6.02
2.50
1.16
0.59
0.33
0.19
0.12
0.08
The fluid temperature sensor can fail in the following ways:
• Sensor open circuit
• Short circuit to 12 or 5 volts
• Short circuit to earth.
The EAT ECU will detect temperature sensor failure when the vehicle speed exceeds 12.5 mph
(20 km/h) and the temperature sensor provides a reading of less than -30°C (-22°F). In the event
of a fluid temperature sensor signal failure any of the following symptoms may be observed:
• Upshift to 5th gear inoperative
• Torque reduction request from the EAT ECU to the ECM inoperative.
Selector and inhibitor switch
The selector and inhibitor switch is located on the selector shaft on top of the gearbox. The switch
is connected via a 10 pin connector C0244 to the main harness. The switch receives battery
voltage from the main relay via fuse 4 in the engine compartment fusebox.
The EAT ECU is provided with a voltage output from the selector and inhibitor switch that
corresponds with the gear position the driver has selected.
The EAT ECU determines the position of the selector lever by monitoring seven sets of contacts
in the selector and inhibitor switch which are operated by the selector shaft.
Each set of contacts corresponds to one of the seven selector lever positions (PRND421). Only
one set of contacts will supply battery voltage to the EAT ECU at any one time. The EAT ECU
monitors the switch output every 10 ms.
A pair of contacts are provided for the crank inhibit circuit. The contacts are only closed when the
selector lever is in the 'P' and 'N' positions.
The two contacts are wired in series with the EWS3D immobilisation ECU. When the selector lever
is in any position other than 'P' or 'N', the feed from the ignition switch to the immobilisation ECU
is broken by the open contacts, preventing starter motor operation.
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In the event of a selector and inhibitor switch signal failure, any of the following symptoms may be
observed:
• Upshift to 5th gear inoperative
• Torque converter lock-up inoperative
• Torque reduction request from the EAT ECU to the ECM inoperative
• Cranking disabled if fault is on the two inhibitor switch contacts.
Selector position switch
Figure 145
Gear lever selector assembly
The gear selector lever assembly comprises a shift lock solenoid, a key interlock mechanism (if
fitted), an LED module and a sport/manual switch.
A nylon cast plate provides the location for the selector lever components. The plate is secured to
the floor pan with six integral studs and nuts. A rubber boot protects the assembly from dirt and
moisture under the vehicle and also isolates vibrations from the lever.
The selector lever is attached to a gimbal mounting which allows gear selection of PRND421 in a
forward and backward direction and selection between automatic and sport/manual in a left and
right transverse direction. When sport/manual mode is selected, the lever can be moved in a
forward or backward direction to select + or - for manual operation.
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Gear selector assembly
Figure 146
1.Park/Reverse release button
2.Hill descent control switch
3.LED Module
4.Selector lever
5.Shift interlock solenoid
6.Key interlock mechanism
markets only)
7.Selector cable
8.Mirror fold ECU (if fitted - reference only)
9.Sport/manual switch connector
10.Sport/manual switch
(Selected
There are seven selector lever positions:
• P (Park) - prevents the vehicle from moving by locking the gearbox.
• R (Reverse) - select only when vehicle is stationary and the engine is at idle.
• N (Neutral) - no torque transmitted to the drive wheels.
• D (Drive) - this position uses all five forward gears. Normal position selected for conventional
driving.
• 4 - this position uses 1st to 4th gears only.
• 2 - this position uses 1st and 2nd gears only.
• 1 - this position uses 1st gear only.
• S/M (Sport/Manual - Steptronic) - this position uses all five gears as in 'D', but will shift up
at higher engine speeds, improving acceleration.
• + and - - movement of the selector lever in the +/- positions, when the selector lever is in the
'S/M' position, will operate the gearbox in manual (Steptronic) mode, allowing the driver to
manually select all five forward gears.
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The selector lever position is displayed to the driver on the LED module in the centre console and
in the instrument pack and corresponds with the position of the selector lever. The LED module
illumination and instrument pack display is determined by the selector and inhibitor switch
assembly on the gearbox, with the exception of the 'S/M' LED and the 'Sport' instrument pack
display which are operated by a hall effect sensor located on the sport/manual switch.
All vehicles with an automatic gearbox incorporate an interlock solenoid at the bottom of the lever,
which prevents the lever being moved from P (Park) unless the ignition switch is in position II and
the foot brake is applied.
In selected markets, a key interlock mechanism, operated by a Bowden cable from the ignition
switch barrel assembly, is also operated by the selector lever park position. The mechanism
prevents the ignition key from being removed from the ignition barrel when the selector lever is not
in the park position. The mechanism also prevents the selector lever from moving from the 'P'
position until the igntion switch is in position II.
Sport/Manual switch
Figure 147
1.Connector
2.PCB
3.'4' sensor
4.'D' sensor
5.'N' sensor
6.'+' (plus) sensor
7.'-' (minus) sensor
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The sport/manual switch comprises a PCB and connector socket which is located to the left of the
selector lever and is an integral part of the selector lever assembly and cannot be serviced
separately. The switch is connected to the main harness by a twelve pin connector.
The sport/manual switch has five proximity sensors which correspond to the D, N, 4 and +/positions. The selector lever has two targets. An upper target is aligned with the DN4 sensors and
the lower target is aligned with the +/- sensors.
When the selector lever is in the D position, the D sensor is aligned with the target and the EAT
ECU receives a signal that D is selected. When the selector lever is moved to the S/M (sport)
position, the target moves away from the sensor. This is sensed by the ECU which then initiates
sport mode.
The sensors in the N and 4 positions inform the ECU that D has been deselected, but not to the
S/M position, preventing the ECU from incorrectly initiating sport mode.
When the selector lever is moved to the S/M position, the target moves away from the D sensor.
If the EAT ECU does not receive a signal from either the 4 or N sensors, it determines that sport
has been selected. The lower target is positioned between the two sensors for +/- selection. If the
selector lever is not moved to the +/- positions, the ECU keeps the gearbox in sport mode. If the
ECU senses a signal from either the + or - sensor, it initiates manual mode and selects the manual
gear selection requested. Manual mode will be maintained until the ECU senses a signal from the
D sensor.
Shift interlock solenoid
The shift interlock solenoid is controlled by the EAT ECU. The solenoid receives a battery feed
from the ignition switch position II.
When the ignition is switched to position II and the selector lever is in the park position, the EAT
ECU provides a earth for the solenoid which energises, deploying a pin which locks the lever in
park.
The brake switch receives a battery feed which is passed to the EAT ECU when the brake pedal
is depressed. The ECU senses the brake switch signal and removes the earth path for the
interlock solenoid, which retracts the pin and allows the selector lever to be moved from park.
LED module
The LED module is located in the selector lever surround and is secured with two integral clips.
The module is connected to the main harness by a 12 pin connector C0675.
The LED module illuminates the applicable LED for the P, R, N, D, 4, 2, 1 and S/M positions. When
the side lamps are switched on, all the LED's are illuminated at a low intensity, with the selected
LED illuminated at a higher intensity.
Selector cable
The selector cable is a Bowden type cable that connects the selector lever to an input lever on the
gearbox.
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A 'C' clip secures the outer cable to the selector lever assembly; the gearbox end of the outer cable
is secured to a bracket on the gearbox by an integral clip. The inner cable is adjustable at the
connection with the gearbox input lever.
Brake switch
The brake switch is located on the pedal box below the fascia. The EAT ECU uses this switch to
monitor brake pedal application status. The information is input to pin 43 of the EAT ECU on a
hardwired connection from the switch.
The EAT ECU can allow the gearbox to apply more engine braking therefore slowing down the
vehicle in a shorter distance and reducing brake pad wear. The EAT ECU achieves engine braking
by applying the low and reverse clutches.
The brake switch can fail in the following ways:
• Switch open circuit
• Short circuit to 12 or 5 volts
• Short circuit to earth.
In the event of a brake switch signal failure, extra gearbox braking will not occur and shift lock
solenoid (if fitted) will not function.
Instrument Pack
The instrument pack displays gearbox selection and fault information in the LCD and can
illuminate the MIL for OBD emission related faults.
Figure 148
1.Malfunction Indicator Lamp (MIL)
2.Gearbox mode display
3.Liquid Crystal Display (LCD)
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The gearbox related displays in the instrument pack are controlled by the ECM which transmits
CAN message signals to operate the lamps and the LCD.
Malfunction Indicator Lamp (MIL)
The MIL is located in the instrument pack and is illuminated in an amber colour and shows a
silhouette of an engine. The lamp is illuminated by a CAN message from the ECM on receipt of a
CAN message from the EAT ECU.
Emission related faults are detected by the OBD feature in the EAT ECU and will illuminate the
MIL in the instrument pack.
Liquid crystal display (LCD)
The LCD is located in a central position in the instrument pack. In addition to displaying the
odometer and trip meter, the LCD also displays the current gearbox status. The following table
shows the characters displayed and their definition.
Character
P
R
N
D
DSport
1
2
3
4
5
4 and F
Flashing alternately
Description
Park
Reverse
Neutral
Drive
Sport Mode
Manual 1st ratio
Manual 2nd ratio
Manual 3rd ratio
Manual 4th ratio
Manual 5th ratio
Severe fault detected - Limp home mode stategy initiated
The EAT ECU transmits the selector lever position through the CAN bus to the ECM. The ECM
processes this information and passes it to the instrument pack in the form of CAN messages to
display the gearbox status.
If the gearbox develops a fault and adopts the limp home mode, the LCD will alternately display
'F' and 4'' to alert the driver that a fault has occurred and limp home mode is operational.
Electronic automatic transmission control unit
The EAT ECU is located in the environmental box (E-Box) in the engine compartment, adjacent
to the ECM. The ECU is connected to the vehicle wiring by a 54 pin connector C0932.
The EAT ECU uses a 'flash' Electronic Erasable Programmable Read Only Memory (EEPROM).
This enables a new or replacement EAT ECU to be externally configured. EEPROM also allows
the EAT ECU to be updated with new information and market specific data.
To input new information and market specific data the EAT ECU must be configured using
TestBook. The EEPROM allows the ECU to be reconfigured as many times as necessary to meet
changing specifications and legislation.
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The EAT ECU memorises the signal values of the gearbox sensors and actuators. These stored
values ensure optimum gearbox performance is achieved at all times.
This information is lost if battery voltage is too low, for example if the battery becomes discharged.
The EAT ECU reverts to default readings on first engine start after a battery discharge or
disconnection. The EEPROM facility in the ECU allows the stored values to be re-learnt, ensuring
optimum gearbox performance.
If these signals are not within the EAT ECU stored parameters, the ECU will make adjustments to
the operation of the gearbox through the actuators to provide optimum drivability and
performance.
The inputs from the sensors constantly updates the EAT ECU with the current operating condition
of both the gearbox and the engine. The ECU compares this current information with mapped
information stored within its memory. The ECU will make any required adjustment to the operation
of the gearbox through the following actuators:
• Gear control solenoid valves
• Lock-up solenoid valve
• Line pressure solenoid valve.
The EAT ECU also interfaces with the following:
• Engine Control Module (ECM) via the CAN
• Instrument pack via the CAN
• Diagnostic socket via the ISO 9141 K line.
Connector C0932 Pin Details
Figure 149
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The following table shows the harness connector face view and pin numbers and input/output
information.
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
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Description
Diagnostic ISO9141 K Line
Not used
2/4 brake duty solenoid valve
2/4 brake timing solenoid valve
Vehicle speed sensor
Not used
Selector 3rd range switch
Selector 2nd range switch
Earth
Reduction timing solenoid valve
Not used
CAN Bus - Low
CAN Bus - Low2
Shift solenoid valve B
Shift solenoid valve A
Lock-up duty solenoid valve
Solenoid valves - Earth
Line pressure duty solenoid
Selector shift up (+) sensor
Sensors - Earth
Intermediate shaft speed sensor
Not used
Not used
Turbine speed sensor
Selector 'N' range switch
Selector 'R' range switch
Selector 'D' range switch
Kick down inhibit
Not used
Selector 'P' range switch
Normal (drive) mode switch
Not used
CAN Bus High
CAN Bus High2
Not used
12V Battery voltage from main relay
Selector shift down (-) sensor
Earth
Fluid temperature sensor
Not used
Sport / Manual hold switch
Not used
Brake switch signal
Not used
Selector 4th range switch
Not used
Not used
Shift lock solenoid fault
Input/Output
Input/Output
Output
Output
Input
Input
Input
Input
Output
Input/Output
Input/Output
Output
Output
Output
Input
Output
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input/Output
Input/Output
Input
Input
Input
Input
Input
Input
Input
Input
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Pin No.
49
50
51
52
53
54
Description
Cruise switch signal (from cruise control ECU)
Shift lock solenoid earth
Not used
Shift solenoid valve C
Low clutch timing solenoid valve
12V Battery voltage from main relay
Input/Output
Input
Input
Output
Output
Input
Main relay
The main relay is located in the engine compartment fusebox and supplies battery voltage to the
EAT ECU, in addition to other vehicle components. The main relay is energised by the ECM when
the ignition is switched on.
When the ignition is switched off, the ECM will maintain the main relay in an energised state for
several minutes. This allows for cooling fan operation to continue after the engine has been
switched off and allows other vehicle ECU's to remain active. The EAT ECU remains active for a
short period after the ignition is switched off to allow EEPROM fault code data to be stored.
In the event of a main relay failure, any of the following symptoms may be observed:
• The gearbox will be locked in 4th gear (limp home mode)
• No CAN communications will be available.
Diagnostics
A diagnostic socket allows the exchange of information between the EAT ECU and TestBook. The
diagnostic socket is located behind the centre console, in the passenger footwell.
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Figure 150
1.Diagnostic socket
The diagnostic socket is connected to the EAT ECU on an ISO9141 K Line. The system uses a
'P' code diagnostic strategy and can record faults relating to the gearbox operation. The codes can
be retrieved using TestBook or any diagnostic tool using Keyword 2000 protocol.
Diagnostic Trouble Codes (DTC)
The following table lists P codes, affected components and fault description.
The diagnostics related to diagnostic trouble codes introduced by ECD3 are disabled on vehicles
built prior to the ECD3 compliance date.
P Code
P0702
P0705
P0710
P0715
P0720
P0732
P0732
P0733
P0734
P0735
P0736
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Component
GND return (Sensor earth)
Selector and inhibitor switch input
ATF temperature sensor
Turbine speed sensor
Vehicle speed sensor
1st gear ratio
2nd gear ratio
3rd gear ratio
4th gear ratio
5th gear ratio
Reverse gear ratio
Description
Short circuit to battery
Multiple signal or No signal
Signal out of range
No signal
No signal
Out of range
Out of range
Out of range
Out of range
Out of range
Out of range
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P0740
P0743
P0748
P0753
P Code
Component
Lock-up clutch solenoid
Lock-up duty solenoid
Line pressure duty solenoid
Shift solenoid A
P0758
P0763
P0790
P1562
P1605
P1715
P1748
Shift solenoid B
Shift solenoid C
Mode switch input
Power supply voltage
EAT ECU EEPROM
Intermediate speed sensor
2-4 brake duty solenoid
P1785
P1786
P1787
Low clutch timing solenoid
Reduction timing solenoid
2-4 brake timing solenoid
P1815
P1825
P1840
P1841
P1842
P1843
P1844
Steptronic (manual) +/- switch input signals
Shift interlock ECU
CAN Bus
CAN Bus monitoring
CAN level monitoring
CAN timeout monitoring
Engine RPM (Speed signal)
Engine temperature signal
Torque reduction signal
Throttle angle signal
Virtual throttle angle
Description
Out of range
Short circuit to earth or battery
Short circuit to earth or battery
Open circuit or short circuit to earth or
battery
Short circuit to earth or battery
Short circuit to earth or battery
Multiple signal
Out of range
Error flag set
No signal`
Open circuit or short circuit to earth or
battery
Short circuit to earth or battery
Short circuit to earth or battery
Open circuit or short circuit to earth or
battery
Multiple signals/No signal
Shift interlock failure
CAN Bus malfunction
CAN Bus off
Incompatible
CAN Bus missing nodes detected
Error flag set
Error flag set
Torque reduction volume not achieved
Error flag set
Error flag set
Operation
The EAT ECU controls the following functions:
• Gear shift scheduling
• Lock-up control
• Line pressure control
• Driving mode engagement
• Sport mode engagement
• Manual (Steptronic) mode engagement
• Reverse inhibit
• Hill mode strategy engagement
• Downhill recognition
• Cruise mode engagement
• Cooling strategy engagement
• Selector position display
• Driving mode display
• Fault status
• Fault code storage
• Emergency/Fail-safe program control
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Transmission control diagram
20
1
2
3
4
21
5
19
18
6
17
7
16
15
14
13
8
10
12
11
9
A
D
J
M44 1615
Figure 151
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A= Hardwired D= CAN Bus J= Diagnostic Bus
1.Intermediate speed sensor
2.Vehicle speed sensor
3.Turbine speed sensor
4.Fluid temperature sensor
5.Solenoid valves and valve block
6.EAT ECU
7.ABS ECU/Modulator
8.Engine Control Module (ECM) - M47R
9.Engine Control Module (ECM) - KV6
10.Instrument pack
12.Cruise control interface ECU - KV6
(Hardwired)
13.Diagnostic socket
14.Brake switch
15.PRND421S/M LED Module
16.Sport/manual switch
17.Shift interlock solenoid
18.Selector and inhibitor switch
19.EWS3D immobilisation ECU
20.Starter relay
21.Main relay
11.Cruise control interface ECU - M47R
(CAN)
Gear Shift Scheduling
The EAT ECU uses the relationship between the vehicle speed and the throttle position to carry
out gear shift scheduling. Depending on these inputs, the EAT ECU controls gear selection using
the three shift solenoid valves located in the valve block.
Lock-Up Control
The EAT ECU monitors the relationship between vehicle speed and throttle position to calculates
when to lock-up the torque converter.
Lock-up control is possible in 4th and 5th gears. For example, lock-up is possible at high speed
cruising with low throttle position. Torque converter lock-up is also provided in 2nd and 3rd gears
when high fluid temperatures are detected by the ECU.
A refinement to the torque converter lock-up system is the reduction of harshness or shock during
torque converter lock-up.
The EAT ECU controls the lock-up solenoid valve to provide a smooth lock-up function. The
solenoid is operated slowly, and gradually varies the fluid pressure to the lock-up control valve.
This causes the lock-up clutch to engage slowly, producing a smooth operation.
To promote engine warm-up at low temperatures, the EAT ECU will inhibit lock-up if the gearbox
fluid temperature is below 40°C (104°F).
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Line Pressure Control
Line pressure refers to the operating fluid pressure that is supplied to the multi-plate clutches,
multi-plate brakes and brake band within the gearbox.
Line pressure control provides smooth vehicle operation and gear shift action. The line pressure
control is continuously responding to current driving conditions to regulate and deliver the optimum
operating pressure at all times. For example, line pressure is lower under normal operating
conditions than it would be under hard acceleration.
The EAT ECU controls line pressure by actuating the line pressure solenoid valve in the valve
block. The ECU calculates the line pressure required by using engine speed, vehicle speed and
throttle position.
High line pressures will cause very harsh gearshifts and gear engagement. Low line pressure will
cause gearshifts to take an excessive amount of time to change, which will quickly burn out the
clutches, brakes and brake band within the gearbox.
Driving Modes
There are five different driving modes that the driver can select:
• Normal mode
• Sport mode
• Manual (Steptronic) mode
• Hill Descent Control (HDC) mode
• Cruise mode.
Normal, sport, cruise and HDC modes are selected manually by the driver. Fast off and stop go
modes are controlled by the EAT ECU responding to driving conditions.
The different modes are selected by the gear selector lever or, in the case of cruise mode and
HDC, a separate switch. The gear change scheduling is altered to correspond with the mode
selected.
Normal mode
On power up the EAT ECU always initialises normal mode. In this mode all automatic/adaptive
modes are active. Normal mode uses gear shift and lock-up maps which allows vehicle operation
which is a compromise between performance, fuel consumption and emissions.
Sport mode
In sport mode the EAT ECU controls the gearbox to downshift more readily and use gear change
schedules that hold the lower gears for longer at high engine speeds. This enhances acceleration
and vehicle responsiveness. Sport mode is selected by moving the gear selector lever to the 'S/
M' position. 'Sport' is displayed in the instrument pack LCD when this mode is selected.
Manual (Steptronic) mode
Manual mode allows the driver to operate the gearbox as a semi-automatic, Steptronic gearbox.
The driver can change up and down the five gears with the freedom of a manual transmission.
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Gearshift maps programmed in the EAT ECU protect the engine at high engine speeds by
automatically changing up to prevent engine over speed and changing down to prevent stalling.
Manual mode is entered by moving the selector lever to the 'S/M' position and moving the lever to
either the + or - positions to move the gearbox up and down the five gear ratios. Manual mode is
exited by moving the selector to position 'D'.
HDC mode
The HDC mode assists the ABS in controlling the descent of the vehicle in either 1st gear ratio or
reverse gear ratio. HDC mode is initiated by selecting 1 or R on the selector lever, depressing the
HDC button adjacent to the selector lever and throttle pedal released (low demand position). The
instrument pack illuminates the HDC warning lamp and the LCD will display the selected gear (1
or R).
The EAT ECU will maintain the selected gear ratio and apply engine braking the assist ABS in
controlling the vehicle's descent.
Cruise mode
Cruise control is activated by depressing the cruise control switch in the centre console. When
cruise control is active, the EAT ECU senses this as a hardwired input from the cruise control ECU
(KV6 models) or interface unit (M47R models). In cruise mode the EAT ECU uses a dedicated
gearshift map to control the gearbox and assist the cruise control ECU in maintaining the vehicle
speed. The gearbox cruise mode is cancelled by applying the brake pedal or deselecting cruise
control. Cruise mode is suspended when the throttle demand is increased and is reinstated when
the pedal is released and the set speed resumed. Cruise mode is also suspended when the
suspend switch on the steering wheel is pressed.
Reverse inhibit
If the vehicle exceeds 6 mph (10 km/h) in the forward direction, and Reverse (R) gear is selected,
the EAT ECU switches on the low clutch timing solenoid valve in the valve block, which drains the
fluid from the reverse clutch.
This function prevents the gearbox from engaging reverse gear when the vehicle is moving in a
forward direction, so preventing damage to the gearbox.
Hill mode
Hill mode modifies the gearbox shift pattern to assist drivability on steep gradients. The EAT ECU
detects the conditions to activate hill mode by monitoring the engine torque values, throttle angle
and engine speed. This mode also assists driving at high altitudes and trailer towing.
Downhill recognition
On downhill slopes there is a tendency for automatic gearboxes to upshift due to the increase in
vehicle speed and the decrease in throttle angle.
The reduction in engine braking causes the driver to use the brakes. A downhill slope is
recognised by EAT ECU as an increase in vehicle speed with the decrease in throttle angle.
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When a downhill slope is recognised and the brakes are applied, the shift pattern is over-ruled and
the gearbox shifts down a gear if engine speed allows. The downhill mode is cancelled upon
application of the throttle.
Cooling strategy
The purpose of the cooling strategy is to reduce engine and gearbox temperatures during high
load conditions, for example when towing trailers. Under these conditions the engine and gearbox
may generate excessive heat.
While in any gear other than 5th, or in 5th gear with the vehicle speed above 38 mph (61 km/h), if
the gearbox fluid temperature increases to 127°C (260°F), the EAT ECU employs the cooling
strategy.
This strategy consists of a separate shift and torque converter lock-up map that allows torque
converter lock-up or gear changes to occur outside of their normal operating parameters.
This will reduce either the engine speed or the slip in the torque converter, therefore reducing the
heat generated.
The EAT ECU cancels the cooling strategy when gearbox fluid temperature decreases to 120°C
(248°F).
Engine cooling fan
If the gearbox fluid temperature increases to 110°C (230°F), the EAT ECU sends a cooling request
message to the ECM on the CAN bus. The ECM then switches the engine cooling fan on, or if it
is already on, keeps it on, to maintain the air flow through the fluid cooler.
The EAT ECU cancels the cooling request when the fluid temperature decreases to 100°C
(212°F).
Diagnostics
If the EAT ECU detects a failure in an associated component, a fault code will be stored in the EAT
ECU memory. TestBook is used to retrieve these fault codes to identify the cause of the failure.
Gearbox fault status
If the EAT ECU detects a fault with the gearbox system it will enter a fail safe mode. There are
many fail safe modes the EAT ECU can adopt.
The EAT ECU will adopt the fail safe mode most acceptable for the driver and will ensure the least
amount of damage to the gearbox.
When a fault is detected a CAN message is sent from the EAT ECU to the instrument pack and
the MIL will be illuminated if the fault is related to OBD. If the ECU is able to implement a limp home
mode, the instrument pack LCD will display '4' and 'F' alternately as the gearbox status display.
Some faults may not display '4' and 'F' in the instrument pack, but the driver may notice a reduction
in shift quality.
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Engine speed and throttle monitoring
The ECM constantly supplies the EAT ECU with information on engine speed and throttle angle
through messages on the CAN bus. This information is used by the EAT ECU to calculate the
correct timing of gear changes.
If the messages are not received from the ECM, the EAT ECU will implement a back-up strategy
to protect the gearbox from damage, whilst allowing the vehicle to be driven.
In the event of an engine speed signal failure any of the following symptoms may be observed:
• Decrease in fuel economy
• Increase in engine emissions.
In the event of a throttle position signal failure, any of the following symptoms may be observed:
• Harsh gear changes
• No kickdown
• Torque reduction request inhibited.
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Getrag 283
Getrag 283
General
Figure 152
All M47R Diesel Freelanders with manual transmission feature a newly developed Getrag
gearbox. The gearbox, named 283, is made in Italy in a brand new factory that meets the most
demanding manufacturing and quality standards in the world.
The new gearbox has been designed to handle the high torque outputs of the M47R engine and
has a capacity of 273Nm. It is 'fill for life', requiring no oil change.
Features of the Getrag 283 transmission are:
• Synchromesh is provided on reverse as well as all forward gears. The lack of reverse gear
synchromesh can result in reverse gear crash and customer dissatisfaction
• First and second gears have two-cone synchromesh. This reduces gear change loads where
the highest speed differences have to be overcome and the greatest forces endured
• The gear machining process reduces gear noise
• The hydraulically activated clutch and concentric slave cylinder together give a light pedal
load and smooth travel
• First gear switch for hill descent control
• IRD differential necessitates the removal of the transmission differential
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Intermediate reduction drive
Figure 153
1.Primary shaft
2.Main casing
3.Differential unit
4.RH Housing
5.Laygear
6.Pinion housing
7.Rear output pinion
8.Hypoid gear set
9.Intermediate shaft
The IRD is fitted in place of the conventional transfer box, and is attached to the manual or
automatic gearbox. The combination of the two units provides drive to the front and rear wheels.
The IRD incorporates a differential unit to control the proportion of drive delivered to each front
wheel, and in addition, it operates in conjunction with the viscous coupling to give the vehicle a
self-sensing four wheel drive system. The main casing, cover and pinion housing are
manufactured from cast aluminium.
The unit comprises of a main casing, a RH housing, primary shaft, an intermediate shaft, a
differential unit, a laygear, hypoid gear set, a rear output pinion and a pinion housing. An oil cooler,
connected to the vehicle cooling system, is fitted to prevent overheating of the IRD lubricating fluid.
The main casing also incorporates the oil level/drain plugs and a breather outlet. There are a total
of seven taper roller bearings and one parallel roller bearing supporting the primary shaft,
differential and output shaft assemblies.
Four seals, internal to the IRD, are used to prevent mixing of the IRD and gearbox lubricating
fluids.
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Clutch
The clutch system is a conventional diaphragm type clutch operated by a hydraulic master
cylinder. The hydraulic system is manufactured from plastic. The system is sealed for life and can
only be replaced in its entirety. The clutch requires no adjustment to compensate for clutch drive
plate wear.
The hydraulic clutch comprises a master cylinder and a slave cylinder/hydraulic release bearing
connected by a two piece plastic tube. The system is supplied as a two piece system, pre-filled
with hydraulic fluid to ease replacement and minimize repair times. The master cylinder is
manufactured from injection moulded thermoplastic which can operate in extremes of
temperatures.
The master cylinder is located in the bulkhead in a specially designed hole which allows the
cylinder to be installed at a 45° angle from vertical. Once located, the master cylinder is rotated to
the vertical position and is automatically secured in this position. The master cylinder has a piston
which moves in the cylinder. A rod is attached to the piston and to a spigot on the clutch pedal. A
fluid reservoir is mounted on the engine compartment side of the master cylinder and is sealed
with a removable rubber cap.
A nylon tube is connected to the master cylinder by a swivel coupling which aids installation and
alignment. The tube is fitted with a self sealing, quick fit coupling which mates with a similar
connection on the slave cylinder tube.
The slave cylinder is located inside the clutch housing and is integral with the release bearing. The
assembly is located and supported on a tube which is fitted over the gearbox input shaft. The pipe
from the slave cylinder passes through a sealing grommet in the gearbox clutch housing and is
terminated with a self sealing, quick fit coupling, which mates with the coupling on the pipe
connecting the master cylinder. A second pipe is also attached to the slave cylinder and emerges
from the sealing grommet and is terminated with a bleed nipple.
A coil spring is located between the piston of the slave cylinder and the release bearing. The spring
holds the release bearing against the pressure plate diaphragm.
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Braking system
Braking system
Foundation brakes
Vehicle braking is provided by disc brakes on the front wheels and drum brakes on the rear
wheels. The foot brakes are operated by a diagonally split, dual circuit hydraulic system with
vacuum servo power assistance. A cable operated handbrake operates on the two rear brakes.
The ABS features 4-wheel electronic traction control and hill descent functions as well as anti-lock
braking and electronic brake distribution.
Figure 154
RHD shown, LHD similar
1.Brake servo assembly
2.Rear brake
3.Front brake
4.Engine inlet manifold (petrol models)
5.Vacuum check valve
6.Master cylinder assembly
7.Vacuum check valve (diesel)
226
Braking system
8.Vacuum pump (diesel models)
9.ABS modulator/ECU
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Anti lock braking system
Freelander 2001 will be available with a new ABS system: TEVES MK20 SCS system. The system
comprises the following features:
• Anti-lock braking system
• Hill descent control
• Electronic traction control
• Electrical brake-force distribution
• CAN communication link
The system communicates via CAN with the engine management system, the instrument pack
and, on automatic derivatives, with the transmission control unit. the system comprises the
following components:
• Electronic control unit
• Modulator (attached to the ECU)
• Wheel speed sensors
• Mechanical brake switch
• Brake fluid level switch
• HDC relay and switch
• Longitudal accelerometer
Electronic control unit
The Electronic Control Unit (ECU) determines the speed and acceleration of each wheel, controls
appropriate hydraulic functions and monitors system operation for fault conditions and interfaces
to other vehicle systems. The ECU is attached to the Modulator unit and is mounted underbonnet
on the RHS valence behind the headlamp.
Under the following conditions the ECU is programmed to switch off the main driver which will
result in the illumination of the ABS, TC, HDC and EBD warning lamps:
• If the IGN voltage drops to values, which are not sufficient to maintain a stabilised, supply
voltage for the processors. This voltage is below the functional operating voltage of 8 volts.
The controller will invariably switch on again when the minimum operating voltage of 10 volts
is reached.
• If the following failures or errors are detected:
• Valve failure
• Two wheel speed sensor failure
• Main driver failure
• Redundancy error
• Overvoltage
The ECU will also inhibit the ABS function, traction control, hill descent control and illuminate their
respective warning lamps without switching off the main driver in the following circumstances:
• Supply voltage at pin 12 < 8 volts
• Failure of one or more of the wheel speed sensors
• Pump motor failure
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Hydraulic modulator
The hydraulic unit of the modulator consists of a pump and 12 solenoid operated valves,
accumulator and damper chambers. During normal braking where ABS intervention is not
required, brake fluid passes straight through de-energised inlet valves (normally open). Where
ABS intervention is required, pressure is maintained at a wheel by closing the appropriate inlet
valve. When pressure needs to be released from a brake circuit, the appropriate outlet valve is
opened (when output valve is opened the Inlet valve must be closed) and the brake fluid is allowed
to flow into the reservoir. Brake fluid is returned, via the return pump, to the Master cylinder line
via the damper chamber.
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ABS hydraulic circuits
Figure 155
1.Front right cylinder
2.Rear left cylinder
3.Rear right cylinder
4.Front left cylinder
5.Low pressure accumulator
6.Damper chamber
7.Recirculation pump
8.Pulsation damper
9.Master cylinder
10.Reservoir
11.Modulator
12.Inlet valve
13.Outlet valve
14.Electric shuttle valve
15.Separation valve
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Brake fluid pressure - (inlet)
The hydraulic circuit of the ABS modulator consists of the Primary and Secondary feeds from the
Brake Master cylinder. These are fed into the modulator by two Ø 6 mm. brake pipes. The input
pipes are easily distinguished by their size, compared to the four Ø 4.76 mm. outlet pipes.
The ECU can detect electrical failure of each the inlet valves and will generate relevant fault codes
which can be accessed via TestBook.
Brake fluid pressure - (outlet)
The hydraulic outlet circuit of the ABS modulator consists of the four pipes leading to the front
calipers and rear brake drums. The four pipes transmit the brake fluid usually at the pressure
determined by the drivers brake application, but during ABS, EBD, TC and HDC intervention at
the pressures modified by the ABS ECU. The pipes are attached by a series of clips into the body
and terminate at the caliper/drum via a flexible hose.
The ECU can detect electrical failure of each the output valves and will generate relevant fault
codes which can be accessed via TestBook.
Wheel speed sensor
A wheel speed sensor is fitted to each of the four Hub carriers. These sensors inform the ABS
ECU about the speed of each of the road wheels. This measurement is fundamental to the
operation of the braking features. The harness wires that connect the sensors to the ABS unit are
twisted pairs. Since the sensors are reluctor devices (Passive sensor) no output is available when
the road wheels are not turning. Thus, the ABS ECU is unable to test the sensor or the pole wheel
fully until the vehicle is moving.
Failures or malfunctions relating to the sensor, and sensor connections, are detected by the ABS
ECU. In the event of failure of two or more of the sensors the ABS ECU switches off the system
and illuminates the ABS, TC, EBD, and HDC warning lamps.
If a single sensor fails the ABS ECU maintains the minimum functions to provide safe operation
and illuminates the ABS, TC, and HDC warning lamps.
Mechanical brake switch
A mechanical Pedal switch is used to illuminate the stop/brake lamps on the vehicle because of
its high current carrying/switching capabilities. It is also used to input the status of the Brake pedal
to the ABS ECU. This switch is double contact switch where the brake lamp switch (BLS) contact
is open and the brake switch (BS) contact is closed when brake pedal is at rest. When pedal is
depressed, the BLS contact closes and BS contact opens thus supplying 12 volts to the brake/
stoplamps and indicating to the ABS ECU that the pedal has been operated. During the time pedal
is depressed there is a time when both BLS and BS contacts will both be closed, this is required
to do the plausibility check on the switch. The switch used is a carryover from the Range Rover.
Freelander 2001 also has a Hall effect brake pedal position sensor fitted adjacent to the
mechanical brake switch. This is not used by the ABS system but by other system ECU's which
are not compatible with mechanical switches.
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Brake fluid level switch
The brake fluid level switch (BFLS) switch is a Reed switch, and is located within the Brake fluid
reservoir. The brake fluid level switch is connected to the ABS ECU and is switched to ground.
The BFLS is closed when there is correct fluid level. If the switch goes open circuit (low level of
fluid), then the switch will send a CAN message to the ABS ECU to activate the Brake warning
LED in the instrument pack. This also means that if the connector comes off or the wire breaks the
brake warning lamp will be 'on'.
Hill descent control relay and switch
The HDC relay is located inside the engine compartment fusebox. The HDC switch is a latching
switch mounted on the centre console for automatics vehicles and the gear lever for manual
vehicles.
Longitudinal accelerometer
Longitudinal accelerometer
Figure 156
The longitudinal acceleration sensor (sometimes known as "G" sensor) is mounted in-cab near the
centre-line of the vehicle alongside the handbrake lever. It provides additional information to the
ABS ECU regarding vehicle motion, to corroborate inputs from the wheel speed sensors.
The signal produced by the longitudinal accelerometer is used by the ABS ECU to check the
plausibility of the vehicle speed signal. Where the vehicle wheel speed sensors tell the ECU that
the vehicle speed is faster than the actual vehicle body speed.
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Anti-lock braking system
The ABS fitted to Freelander is a four channel system. It has independent control of all four wheels
and works on all terrain.
The ABS ECU takes wheel speed information from sensors, located within the hub carrier, and
monitors the relative deceleration/acceleration of each wheel at all times. These signals are used
to calculate the rotational deceleration rates for each wheel during braking operation. In the event
of a wheel slip occurring (i.e. rotational deceleration being outside of allowable limits), the
hydraulic system will control the brake line pressure by operating the appropriate solenoid valves
within the hydraulic modulator and thus removing some brake pressure from the locked wheel.
Once the wheel deceleration has recovered to within allowable limits the modulator then allows
pressure to be re-applied to the appropriate brake caliper.
If the ECU detects, via the wheel speed sensors, that any of the wheels are tending to lock, the
inlet valves of those wheels are closed and the outlet valves are opened. This fills the low-pressure
accumulators, enabling pressure to be released from the brakes. The activated re-circulation
pump returns the brake fluid via the master cylinder to the fluid reservoir.
To increase pressure to the wheel brakes, the inlets are opened and outlets closed. The fluid is
then replenished from the master cylinder, and if the low pressure accumulators contain fluid,
additionally by the re-circulation pump. By restoring and shutting off the pressure, a pulsating
pedal motion may be felt by the driver.
When ABS intervention is necessary the warning lamp will not illuminate but the driver may
experience audible feedback from the modulator along with the brake pedal vibrating.
If a fault occurs with the system or any of its constituent components the relevant warning lamp in
the IPK will illuminate to inform the driver of the fault.
The ABS warning lamp is 'on' under the following conditions:
• During the initialisation phase and a following test phase controlled by the microprocessor it
then goes off for approximately 0.5 seconds (if there are no current or stored faults). It comes
back on until the vehicle reaches speed of 7 kph. It then goes off provided there are good
wheel speed sensor signals. The lamp will not flash off if there are stored or current faults.
• If there is a system fault which inhibits ABS operation.
• When the controller is switched off as long as voltage is applied at pin 12 (IGN), during
diagnostics
• In the event of CAN communication failure between the IPK and the ABS ECU
Electronic brake-force distribution
This feature controls the front to rear balance of the braking system by electronic braking force
distribution (EBD). This makes sure that under any conditions and loading, the rear wheels will not
lock before the fronts, which would cause handling and stability problems.
EBD uses standard ABS hardware to optimise the braking distribution automatically, below the
point were ABS control would be invoked. This task was previously performed by a pressure
conscious reduction valve (PCRV), which allowed the braking loads to be apportioned between
the front and rear axles under all vehicle-loading conditions.
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The EBD warning lamp is the red brake warning lamp and is illuminated under the following
conditions:
• During the initialisation phase and a following test phase controlled by the microprocessor
• When the controller is switched 'Off' as long as voltage is applied at pin 12 (IGN)
• When the handbrake is applied
• When the brake fluid level is low or when the brake fluid level switch is not connected
• If there is a CAN communication failure between IPK and the ABS ECU
Traction control
This feature uses brake intervention to prevent wheel slipage (i.e. wheel speed faster than vehicle
reference speed) during attempts to accelerate or on a slippery road surface. This is done by the
ECU, which monitors the speed of each wheel. If any wheel is spinning faster than others, brake
pressure is applied to that wheel to slow it down, bringing it in line with other wheel speeds, thus
providing the optimum traction between the road surface and each vehicle tyre.
If ETC is required and the brake pedal is not depressed, the ECU starts the re-circulation pump to
draw fluid into the system from the master cylinder. Additional valves are required for the purpose
of controlling the volumetric flow. The Continental TEVES system uses two additional solenoid
valves in each brake circuit. As the pump starts up, the separation valve blocks the delivery line
to the master cylinder and diverts the fluid flow to the pump circuit. The changeover, or electric
shuttle valves, control fluid flow from the master cylinder and reservoir. Actual wheel control takes
place in the same way as ABS via the control of the individual inlet and outlet valves. Excess
volumetric flow of the pump is routed via the pressure relief valve, which is integrated into the
separation valve on the Continental TEVES system.
The traction control warning lamp is amber in colour and is illuminated in the following
circumstances/conditions:
• It illuminates for a minimum of 2 seconds when TC is active or longer if TC is active for longer
than 2 seconds
• During the initialisation phase and a following test phase controlled by the microprocessor
• In the event of TC fault condition
• Fully 'on' when manual disable TC function is operated
• Flashing when Brakes are hot (over 350°C)
• When the controller is switched 'Off' as long as voltage is applied at pin 12 (IGN)
• During diagnostics
Disabling traction control
To allow the vehicle to be tested on two wheel rolling roads there is a feature which allows the
traction control function to be disabled. To disable traction control the brake pedal has to be
operated 10 times within first 10 seconds of turning 'on' the ignition. When TC is disabled, the TC
warning LED will be illuminated in the instrument pack and no wheel braking will occur during this
period. Also the road speed signal will be an average of the two rotating wheels, and no
wheelspeed sensor faults or 'G' sensor faults will be registered during this period. To re-enable TC
the vehicle must see a 7kph signal on all 4 wheels.
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Should the ETC (or HDC) be active for long periods the temperature of the brakes may cause
damage to the brake components (disks, drums, pads and shoes). To prevent this there is a safety
feature that disables the ETC or HDC if it considers the system is overheating. The system
functions by the ABS calculating the brake temperature. When the first temperature limit is
reached (350°C) is reached the ETC warning lamp will start to flash (if HDC is also 'ON' then the
HDC fault lamp will also flash). When the second temperature limit (400°C) has been reached the
warning lights will continue to flash but the ETC and HDC functionality will become inactive.
Should HDC be active as the second temperature limit is reached the HDC will fade out gradually.
System functionality will return when the brakes have returned to the third limit (300°C).
Hill descent control
This feature allows the vehicle speed to be controlled during a hill descent using the vehicle
Brakes. This feature has to be selected using the Hill descent switch with the selected gear being
'first' or 'reverse' and the brakes below 350°C.
When HDC is selected by operating the latching HDC switch the green LED is illuminated
continuously to indicate HDC is available. If conditions are not met to enable HDC operation, after
the switch is operated the green LED flashes. When going downhill and HDC is selected the
vehicle will maintain a target speed of approximately 7k/ph by applying the brakes if the throttle
pedal is not depressed. When the throttle pedal is depressed the target speed will be relative to
the throttle pedal position and the vehicle will go down faster at the new target speed. If the slope
is not steep enough and the speed is less than the target speed, the vehicle will not accelerate to
reach the target speed. The HDC function is brakes intervention only. There are 2 LED's in the
instrument pack for the HDC function. There is a green LED, which indicates the status of the
HDC function and an amber LED which, indicates HDC system fault when illuminated fully.
Minimum target speeds with the throttle closed are 6 mph (9.6 km/h) in first gear and 4 mph (6.5
km/h) in reverse gear. The first gear target speed is decreased to 4.4 mph (7 km/h) if rough terrain
or sharp bends (detected from ABS sensor inputs) are encountered while already travelling at the
minimum target speed. Minimum target speeds are increased at cold idle to prevent conflict
between the brakes and the engine caused by HDC trying to impose a lower vehicle speed than
is normal for the increased engine speeds at cold idle. Minimum target speeds at cold idle are 7.5
mph (12 km/h) in first gear and 4.4 mph (7 km/h) in reverse gear.
During active braking, the brakes are operated in axle pairs on one or both axles. The braking
effort is distributed between the front and rear axles as necessary to maintain vehicle stability.
Distribution of the braking effort is dependant on direction of travel and braking effort being
applied. To prevent wheel lock, anti-lock braking is also enabled during active braking.
The ABS ECU incorporates a fade out strategy that, if a fault occurs or HDC is deselected during
active braking, provides a safe transition from active braking to brakes off. The fade out strategy
increases the target speed at a low constant acceleration rate, independent of actual throttle
position. If active braking is in operation, this causes the braking effort to be gradually reduced and
then discontinued. The HDC information warning lamp flashes while fade out is in progress.
If the clutch is disengaged during active braking, the HDC information warning lamp flashes after
a delay of 3 seconds. After 60 seconds, if the clutch is still disengaged, the HDC fault warning lamp
flashes and active braking operation fades out.
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To prevent the brakes overheating, the ABS ECU monitors the amount of active braking employed
and, from this, calculates brake temperature. If the ABS ECU determines brake temperature has
exceeded a preset limit, it extinguishes the HDC information warning lamp and flashes the HDC
fault warning lamp to indicate that HDC should be deselected. If active braking continues and the
ABS ECU determines that brake temperature has increased a further 50 C, it fades out active
braking and disables HDC. After fade out, the HDC fault warning lamp continues to flash, while
HDC is selected, until the ABS ECU calculates brake temperature to be at an acceptable level.
This calculation continues even if the ignition is turned off, so turning the ignition off and back on
will not reduce the disabled time. When the ABS ECU calculates the brake temperature to be
acceptable, it extinguishes the HDC fault warning lamp and illuminates the HDC information
warning lamp to indicate HDC is available again. The disabled time is dependant on vehicle
speed; typical times at constant vehicle speeds are as follows:
Disabling of hill descent control and traction control after prolonged use
If the traction control or HDC has been active for a long time, the foundation brakes can get very
hot and damage may occur to the brake components compromising braking efficiency. For this
reason there is an ABS function which inhibits excessive use of traction control and hill descent
control. The way this function works is that the ABS ECU calculates the temperature of the brakes
using internal algorithms. If the first temperature threshold (350°C) is reached then the amber TC
LED and the amber HDC fault LED will start to flash. The green HDC LED wil extinguish A flashing
LED warns the driver that the brakes are getting hot (during this period the TC and HDC function
is still available). If the second temperature threshold (400°C) is reached then the LED's continue
to flash but the functionality is disabled for both TC and HDC. If HDC is operating at the time then
the functionality fades out gradually when 400°C is reached. Vehicle functionality will return to
normal after the brakes have cooled down to below 300°C.
Diagnostics
While the ignition is on, the diagnostics function of the ABS ECU monitors the system for faults.
In addition, the return pump is tested by pulsing it briefly immediately after the engine starts
provided vehicle speed exceeded 4.4 mph (7 km/h) during the previous ignition cycle. If a fault is
detected at any time, the ABS ECU stores a related fault code in memory and illuminates the
appropriate warning lamps in the instrument pack. If a fault exists in a warning lamp circuit, the
lamp will not illuminate during the lamp check at ignition on, but, provided there are no other faults,
the related function will otherwise be fully operational.
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Freelander 2001 MY
Checks performed by diagnostics
Fault
ABS ECU internal failure
On
Status of warning lamps
ETC
HDC
HDC information
Fault
On
On
Off
ECM input failure
Off
On
On
Off*
Sticking throttle
Off
Off
On
Off*
Implausible gear position
input
Off
Off
On
Off*
No reference earth
On
On
On
Off
Failure of ABS sensor
On
On
On
Off†
Failure of 2 ABS sensors
On
On
On
Off*
Failure of more than 2
ABS sensors
On
On
On
Off
Failure of input valve
On
On
On
Off
Failure of more than one
input valve
On
On
On
Off*
Failure of output valve
On
On
On
Off*
Failure of more than one
output valve
On
On
On
Off*
Battery short in more than
two input or output valve
circuits
Return pump or relay fault
On
On
On
Off
On
On
On
Off
ABS
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Braking system
Default strategy
ABS: Disabled.
ETC: Disabled.
HDC: Disabled.
ABS: Enabled.
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in active braking mode.
ABS: Enabled.
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in active braking mode.
ABS: Enabled.
ETC: Enabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in active braking mode.
ABS: Disabled.
ETC: Disabled.
HDC: Disabled.
ABS: Enabled.
ETC: Enabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in active braking mode.
ABS: Enabled on unaffected hydraulic
circuit (if applicable), disabled on
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in braking mode.
ABS: Disabled.
ETC: Disabled.
HDC: Disabled.
ABS: Enabled on unaffected hydraulic
circuit (if applicable), disabled on
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in braking mode.
ABS: Enabled on unaffected hydraulic
circuit (if applicable), disabled on
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in braking mode.
ABS: Enabled on unaffected hydraulic
circuit (if applicable), disabled on
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in braking mode.
ABS: Enabled on unaffected hydraulic
circuit (if applicable), disabled on
affected hydraulic circuit(s).
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in braking mode.
ABS: Disabled.
ETC: Disabled.
HDC: Disabled.
ABS: Disabled.
ETC: Disabled.
HDC: Disabled.
Service Training
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Freelander 2001 MY
Fault
ABS
Brake lamp relay fault
Off
Supply voltage out of limits On
Status of warning lamps
ETC
HDC
HDC information
Fault
Off
On
Off*
On
On
Off*
Default strategy
ABS: Enabled.
ETC: Enabled.
HDC: Enabled.
ABS: Enabled.
ETC: Disabled.
HDC: Immediately disabled if not in
active braking mode, faded out then
disabled if in active braking mode.
* = Flashes if HDC faded out; † = Flashes if HDC in active braking mode
Electrical data
Component resistance and voltage values are detailed below:
Component
ABS brake lamp relay coil
ABS pump relay coil
ABS sensor
Shuttle valve switches, both open (brakes off)
Shuttle valve switches, both closed (brakes on)
Shuttle valve switches, one open, one closed
Inlet solenoid valve
Outlet solenoid valve
Component
First gear switch
HDC switch
Reverse gear switch
Service Training
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Resistance, Ohms
73 to 89
44.4 to 54.4
950 to 1100
2977 to 3067
1007 to 1037
1992 to 2052
5.9 to 7.3
3.0 to 3.6
Signal
Earth when first gear selected.
Open circuit when first gear not selected.
Battery voltage when HDC selected.
Open circuit when HDC not selected.
Battery voltage when reverse gear selected.
Open circuit when reverse gear not selected.
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Freelander 2001 MY
ABS system failure warning lights
Operating condition
Traction
control
(Amber)
'Off'
HDC fault
(Amber)
HDC
Active(Green)
'Off'
'On' (if HDC
selected)
'Off'
'Off'
'On' (if HDC
selected)
'Off'
'Off'
'On'
'On'
'On'
'On'
'On'
'On'
'Off'
'Off'
'Off'
'Off'
'Off'
'On'
'On'
'On'
'Off'
'Off'
'Off'
'Off'
'Off'
'Off'
'Off'
'Off'
'On'
'On'
Flashing 2Hz
'Off'
'Off'
'Off'
'On'
'Off'
'Off'
'Off'
Flashing 2Hz (if
activated by
ATC)
'On'
Flashing 2Hz (if
activated by HDC)
'Off'
-
Brake system
(Red)
ABS (Amber)
LED check (ABS flash
'Off' only occurs if there
are no stored faults
within ABS ECU)
'Off'
Normal operation (With
no failiures and all
conditions satisfied for
all features)
'Off'
Hand brake 'On'
Low brake fluid
ABS failiure only
Traction failiure only
ABS + EBD failiure
ABS ECU not connected
Diagnostic mode
Traction disabled mode
HDC selected
(Conditions not met for
HDC operation)
HDC selected (HDC is
available and vehicle
ready for descent)
HDC failiure only
Brakes overheated
'On'
'On'
'Off'
'Off'
'On'
'On'
'On'
'Off'
'Off'
'On' for 1.7 sec
'Off' for 0.5 sec
then 'on' until
vehicle speed
>7kph then turns
'Off'
'Off' (After LED
check lamp stays
'On' until vehicle
speed >7kph
then turns 'Off'
'Off'
'Off'
'On'
'Off'
'On'
'On'
'On'
'Off'
'Off'
'Off'
'Off'
'Off'
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