COMMON RAIL SYSTEM (CRS) SERVICE MANUAL: General Edition

COMMON RAIL SYSTEM (CRS) SERVICE MANUAL: General Edition
COMMON RAIL SYSTEM (CRS)
SERVICE MANUAL: General Edition
Published : September 2007
Revised : July 2008
00400534EA
Revision History
Date
2007.09
Revision Contents
• SCV: Explanation of compact SCV added to "Suction Control Valve (SCV)".
• "Repair" section added.
2008.07
• Added the "HINO vehicles" explanation to the "Diesel Particulate Filter (DPF)"section.
• Changed the "DIAGNOSTIC TROUBLE CODE (DTC) READING" title to "DIAGNOSTIC TOOL USE (TOYOTA VEHICLE EXAMPLE)".
• Revised the "Intake System Diagnosis" content.
• Revised the "Fuel System Diagnosis" content.
• Added the "Engine ECU Input/Output Signal Check Method" content.
• Added the "(10) Engine start failure (example for TOYOTA, HIACE, and REGIUS
ACE) " content to "Troubleshooting According to Malfunction Symptom (for TOYOTA Vehicles)"
© 2008 DENSO CORPORATION
All rights reserved. This material may not be reproduced
or copied, in whole or in part, without the written
permission of DENSO Corporation.
Table of Contents
Table of Contents
Operation Section
1. GENERAL DESCRIPTION
1.1
Changes In Environment Surrounding The Diesel Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2
Demands On Fuel Injection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3
Types Of And Transitions In ECD (ELECTRONICALLY CONTROLLED DIESEL) Systems . . . . . . . . . . . . . . 1-3
1.4
Common Rail System Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1.5
Common Rail System And Supply Pump Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1.6
Injector Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1.7
Common Rail System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
2. COMMON RAIL SYSTEM OUTLINE
2.1
Layout of Main Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
3. SUPPLY PUMP DESCRIPTION
3.1
HP0 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
3.2
HP2 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22
3.3
HP3 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33
3.4
HP4 Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-47
4. RAIL DESCCRIPTION
4.1
Rail Functions and Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-52
4.2
Component Part Construction and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53
5. INJECTOR DESCRIPTION
5.1
General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-57
5.2
Injector Construction and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-58
5.3
Injector Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-61
5.4
Injector Actuation Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-62
5.5
Other Injector Component Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-63
6. DESCRIPTION OF CONTROL SYSTEM COMPONENTS
6.1
Engine Control System Diagram (Reference) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-66
6.2
Engine ECU (Electronic Control Unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-67
6.3
EDU (Electronic Driving Unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-68
6.4
Various Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-69
7. CONTROL SYSTEM
7.1
Fuel Injection Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-74
7.2
E-EGR System (Electric-Exhaust Gas Recirculation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-85
7.3
Electronically Controlled Throttle (Not Made By DENSO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-87
7.4
Exhaust Gas Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
7.5
DPF System (Diesel Particulate Filter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-89
7.6
DPNR SYSTEM (DIESEL PARTICULATE NOx REDUCTION). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-94
Table of Contents
8. DIAGNOSIS
8.1
Outline Of The Diagnostic Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-95
8.2
Diagnosis Inspection Using DST-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-95
8.3
Diagnosis Inspection Using The MIL (Malfunction Indicator Light) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-96
8.4
Throttle Body Function Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-98
9. END OF VOLUME MATERIALS
9.1
Particulate Matter (PM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-100
9.2
Common Rail Type Fuel Injection System Development History And The World’s Manufacturers. . . . . . . . 1-100
9.3
Higher Injection Pressure, Optimized Injection Rates, Higher Injection Timing Control Precision, Higher Injection
Quantity Control Precision1-101
9.4
Image Of Combustion Chamber Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-103
Repair Section
1. DIESEL ENGINE MALFUNCTIONS AND DIAGNOSTIC METHODS (BASIC KNOWLEDGE)
1.1
Combustion State and Malfunction Cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-104
1.2
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-105
2. DIAGNOSIS OVERVIEW
2.1
Diagnostic Work Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-107
2.2
Inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-108
2.3
Non-Reoccurring Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-110
3. DIAGNOSTIC TOOL USE (TOYOTA VEHICLE EXAMPLE)
3.1
Diagnostic Trouble Code (DTC) Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-112
3.2
Active Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-113
3.3
Supply Pump Initialization Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-113
3.4
Injector ID Code Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-116
4. DIAGNOSIS BY SYSTEM
4.1
Intake System Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-128
4.2
Fuel System Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-128
4.3
Basics of Electrical/Electronic Circuit Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-132
4.4
Engine ECU Input/Output Signal Check Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-137
5. TROUBLESHOOTING
5.1
Troubleshooting According to Malfunction Symptom (for TOYOTA Vehicles). . . . . . . . . . . . . . . . . . . . . . . . 2-145
5.2
Other Malfunction Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-175
6. DIAGNOSIS CODES (DTC)
6.1
DTC Chart (Example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-177
Operation Section
1– 1
1. GENERAL DESCRIPTION
1.1 Changes In Environment Surrounding The Diesel Engine
z Throughout the world, there is a desperate need to improve vehicle fuel economy for the purposes of preventing global warming and reducing exhaust gas emissions that affect human health. Diesel engine vehicles are highly acclaimed in Europe, due to the good fuel economy that diesel fuel offers. On the other hand,
the "nitrogen oxides (NOx)" and "particulate matter (PM)" contained in the exhaust gas must be greatly reduced to meet exhaust gas regulations, and technology is being actively developed for the sake of improved
fuel economy and reduced exhaust gases.
(1) Demands on Diesel Vehicles
• Reduce exhaust gases (NOx, PM, carbon monoxide (CO), hydrocarbon (HC) and smoke).
• Improve fuel economy.
• Reduce noise.
• Improve power output and driving performance.
(2) Transition of Exhaust Gas Regulations (Example of Large Vehicle Diesel Regulations)
• The EURO IV regulations take effect in Europe from 2005, and the 2004 MY regulations take effect in
North America from 2004. Furthermore, the EURO V regulations will take effect in Europe from 2008, and
the 2007 MY regulations will take effect in North America from 2007. Through these measures, PM and
NOx emissions are being reduced in stages.
NOx
PM
g/kWh
g/kWh
Europe
Europe
EURO
EURO
EURO
EURO
EURO
EURO
North America
1998 MY
2004 MY
2007 MY
3.5
North
America
0.11
0.13
1998 MY
0.03
2004 2005
2.7
2.0
2004 MY
0.27
0.013
2007 2008
2007 MY
2004 2005
2007 2008
Q000989E
1– 2
Operation Section
1.2 Demands On Fuel Injection System
z In order to address the various demands that are imposed on diesel vehicles, the fuel injection system (including the injection pump and nozzles) plays a significant role because it directly affects the performance
of the engine and the vehicle. Some of the demands are: higher injection pressure, optimized injection rate,
higher precision of injection timing control, and higher precision of injection quantity control.
[ REFERENCE ]
For further information on higher injection pressure, optimized injection rate, higher precision of injection
timing control, and higher precision of injection quantity control, see the material at the end of this document.
Operation Section
1– 3
1.3 Types Of And Transitions In ECD (ELECTRONICALLY CONTROLLED
DIESEL) Systems
z ECD systems include the ECD-V series (V3, V4, and V5) which implements electronic control through distributed pumps (VE type pumps), and common rail systems made up of a supply pump, rail, and injectors.
Types are the ECD-V3 and V5 for passenger cars and RVs, the ECD-V4 that can also support small trucks,
common rail systems for trucks, and common rail systems for passenger cars and RVs. In addition, there
are 2nd-generation common rail systems that support both large vehicle and passenger car applications.
The chart below shows the characteristics of these systems.
'85
'90
'95
'00
ECD-V1
ECD-V3
· The world's first SPV (electromagnetic
spill valve system) is used for fuel
injection quantity control, so the
quantity injected by each cylinder can
be controlled.
· Maximum Injection Pressure 60 MPa
System
Types and
Transitions
ECD-V4
ECD-V5
· Inner Cam Pumping Mechanism
· Maximum Injection Pressure 130 MPa
· Uses pilot injection to reduce the
engine combustion noise.
· Maximum Injection Pressure
100 MPa
ECD-V4
ECD-V5
ECD-V3
Large Vehicle Common Rail
(HP0)
Passenger Car Common Rail
(HP2)
Common Rail System
· Fuel raised to high pressure by the
supply pump is temporarily
accumulated in the rail, then injected
after the injector is energized.
· Uses pilot injection to reduce the
engine combustion noise
· Maximum Injection Pressure 180 MPa
Supply Pump
Injector
Rail
Q000750E
Operation Section
1– 4
1.4 Common Rail System Characteristics
z The common rail system uses a type of accumulation chamber called a rail to store pressurized fuel, and
injectors that contain electronically controlled solenoid valves to inject the pressurized fuel into the cylinders.
z Because the engine ECU controls the injection system (including the injection pressure, injection rate, and
injection timing), the injection system is independent and thus unaffected by the engine speed or load.
z Because the engine ECU can control injection quantity and timing to a high level of precision, even multiinjection (multiple fuel injections in one injection stroke) is possible.
z This ensures a stable injection pressure at all times, even in the low engine speed range, and dramatically
decreases the amount of black smoke ordinarily emitted by a diesel engine during start-up and acceleration.
As a result, exhaust gas emissions are cleaner and reduced, and higher power output is achieved.
(1) Features of Injection Control
Injection Pressure Control
• Enables high-pressure injection even at low engine speeds.
• Optimizes control to minimize particulate matter and NOx emissions.
Injection Timing Control
• Enables finely tuned optimized control in accordance with driving conditions.
Injection Rate Control
• Pilot injection control injects a small amount of fuel before the main injection.
Common Rail System
Injection Timing Control
Pilot injection
Injection Rate
Optimized and Higher Pressure
· Injection pressure is more than double the current
pressure, which makes it possible to greatly reduce
particulate matter.
Electronic Control Type
Injec
tion
Speed
Injection Pressure
Advance Angle
Particulate
Injection Pressure
Common Rail System
Conventional
Pump
Injection Rate Control
Qua
ntity
Speed
After-Injection
Pre-Injection
Post-Injection
Main Injection
Crankshaft Angle
Injection Quantity Control
Cylinder Injection Quantity Correction
Injection Quantity
Injection Pressure Control
1
3 2 4
Q000751E
Operation Section
1– 5
1.5 Common Rail System And Supply Pump Transitions
z The world's first common rail system for trucks was introduced in 1995. In 1999, the common rail system
for passenger cars (the HP2 supply pump) was introduced, and then in 2001 a common rail system using
the HP3 pump (a lighter and more compact supply pump) was introduced. In 2004, the three-cylinder HP4
based on the HP3 was introduced.
1996
Common Rail
System
1998
2000
2002
1st Generation Common Rail System
HP0
2004
2006
2nd Generation Common Rail System
120MPa
Large Trucks
HP4
Medium-Size Trucks
Pre-Stroke Quantity Adjustment
HP3
180MPa
Suction Quantity
Adjustment
HP2
Compact Trucks
180MPa
Suction Quantity
Adjustment
Passenger Vehicles
Suction Quantity
Adjustment
135MPa
Q000752E
1– 6
Operation Section
1.6 Injector Transitions
97
98
99
00
1st Generation
X1
01
02
03
2nd Generation
G2
· 120MPa
· Pilot Injection
· 180MPa
· Multi-Injection
X2
· 135MPa
· Pilot Injection
Q000753E
Operation Section
1– 7
1.7 Common Rail System Configuration
z The common rail control system can be broadly divided into the following four areas: sensors, engine ECU,
EDU, and actuators.
Sensors
z Detect the condition of the engine and the pump.
Engine ECU
z Receives signals from the sensors, calculates the proper injection quantity and injection timing for optimal
engine operation, and sends the appropriate signals to the actuators.
EDU
z Enables the injectors to be actuated at high speeds. There are also types with charge circuits within the
ECU that serve the same role as the EDU. In this case, there is no EDU.
Actuators
z Operate to provide optimal injection quantity and injection timing in accordance with the signals received
from the engine ECU.
Engine Speed Sensor /
TDC (G) Sensor
Supply Pump
(SCV: Suction Control Valve)
EDU
Accelerator Position Sensor
Injector
Engine ECU
Other Sensors
and Switches
Other Actuators
Diagnosis
Q000754E
1– 8
Operation Section
2. COMMON RAIL SYSTEM OUTLINE
2.1 Layout of Main Components
z Common rail systems are mainly made up of the supply pump, rail, and injectors. There are the following
types according to the supply pump used.
(1) HP0 Type
• This system is the first common rail system that DENSO commercialized. It uses an HP0 type supply
pump and is mounted in large trucks and large buses.
Rail
Supply Pump (HP0 Type)
Injector
Q000755E
Exterior View of Main System Components
Operation Section
1– 9
Engine ECU
Accelerator
Position Sensor
Rail
Rail Pressure Sensor
Fuel Temperature
Sensor
Injector
Coolant Temperature
Sensor
PCV (Pump Control Valve)
Supply Pump
Cylinder
Recognition Sensor
(TDC (G) Sensor)
Crankshaft Position Sensor (Engine Speed Sensor)
Q000756E
Configuration of Main System Components (Example of HP0
(2) HP2 Type
• This system uses a type of HP2 supply pump that has been made lighter and more compact, and is the
common rail system for passenger cars and RVs instead of the ECD-V3.
Rail
Supply Pump (HP2 Type)
Injector
Q000757E
Exterior View of Main System Components
1– 10
Operation Section
EGR Valve
Intake Air Pressure Sensor
Engine ECU
Accelerator Position Sensor
Injector
Rail Pressure Sensor
E-VRV
Coolant Temperature
Sensor
Intake Air Temperature
Sensor
Crankshaft Position Sensor
(Engine Speed Sensor)
EDU (Electronic Driving Unit)
Rail
Supply Pump
Cylinder Recognition Sensor
(TDC (G) Sensor)
Mounting Diagram of Main System Components
Q000758E
Operation Section
Various Sensors
Engine
ECU
1– 11
EDU
Rail Pressure Sensor
Rail
TWV
Pressure
Limiter
Regulating Valve
Fuel Filter
Delivery Valve
Injector
Supply Pump
SCV
(Suction
Control
Valve)
Check Valve
Feed Pump
Plunger
Inner Cam
: Flow of Injection Fuel
: Flow of Leak Fuel
Fuel Tank
Q000926E
Overall System Flow (Fuel)
Operation Section
1– 12
(3) HP3 Type, HP4 Type
HP3 Type
• This system uses an HP3 type supply pump that is compact, lightweight and provides higher pressure.
It is mostly mounted in passenger cars and small trucks.
HP4 Type
• This system is basically the same as the HP3 type, however it uses the HP4 type supply pump, which
has an increased pumping quantity to handle larger engines. This system is mostly mounted in mediumsize trucks.
Rail
HP3
HP4
Supply Pump
Injector
Q000759E
Exterior View of Main System Components
Operation Section
1– 13
Intake Air Throttle Body
EGR Valve E-VRV for EGR
Pressure
Sensor
DLC3 Connector
Engine ECU
Airflow Meter
(with Intake Air
Temperature Sensor)
Accelerator Position Sensor
EDU
R/B
EGR Shut-Off VSV
Rail Pressure Sensor Coolant Temperature Sensor
Pressure Discharge Valve
Injector
Supply Pump
Crankshaft Position Sensor
(Engine Speed Sensor)
HP3
HP4
Fuel Temperature
Sensor
SCV
(Suction Control
Valve)
Cylinder Recognition Sensor
(TDC (G) Sensor)
SCV
(Suction Control
Valve)
Fuel Temperature
Sensor
Mounting Diagram for Main System Components
Q000760E
1– 14
Operation Section
EDU
Various
Sensors
ECU
Pressure Discharge Valve
Rail
Pressure Limiter
Rail Pressure Sensor
Delivery
Valve
Supply Pump
(HP3 or HP4)
Injector
Plunger
SCV
(Suction
Control Valve)
Feed Pump
: Flow of Injection Fuel
: Flow of Leak Fuel
Fuel Filter
Fuel Tank
Q000927E
Overall System Flow (Fuel)
Operation Section
1– 15
3. SUPPLY PUMP DESCRIPTION
3.1 HP0 Type
(1) Construction and Characteristics
• The HP0 supply pump is mainly made up of a pumping system as in conventional in-line pumps (two cylinders), the PCV (Pump Control Valve) for controlling the fuel discharge quantity, the cylinder recognition
sensor {TDC (G) sensor}, and the feed pump.
• It supports the number of engine cylinders by changing the number of peaks on the cam. The supply
pump rotates at half the speed of the engine. The relationship between the number of engine cylinders
and the supply pump pumping is as shown in the table below.
Number of Engine Cylin-
Speed Ratio
ders
(Pump: Engine)
Supply Pump
Number of
Cylinders
4 Cylinders
6 Cylinders
1:2
2
8 Cylinders
Number of Pumping Rotations
Cam Peaks
for 1 Cycle of the Engine (2
Rotations)
2
4
3
6
4
8
• By increasing the number of cam peaks to handle the number of engine cylinders, a compact, two-cylinder pump unit is achieved. Furthermore, because this pump has the same number of pumping strokes as
injections, it maintains a smooth and stable rail pressure.
PCV (Pump Control Valve)
Delivery Valve
Element
Overflow Valve
Cylinder Recognition Sensor
(TDC (G) Sensor)
Feed Pump
Pulsar for TDC (G) Sensor
Tappet
Cam x 2
Q000768E
1– 16
Operation Section
(2) Exploded View
PCV
(Pump Control Valve)
Delivery Valve
Element
Cylinder Recognition Sensor
(TDC (G) Sensor)
Tappet
Cam
Roller
Camshaft
Priming Pump
Feed Pump
Q000769E
Operation Section
1– 17
(3) Supply Pump Component Part Functions
Component Parts
Functions
Feed Pump
Draws fuel from the fuel tank and feeds it to the pumping mechanism.
Overflow Valve
Regulates the pressure of the fuel in the supply pump.
PCV (Pump Control Valve)
Controls the quantity of fuel delivered to the rail.
Pumping
Cam
Actuates the tappet.
Mechanism
Tappet
Transmits reciprocating motion to the plunger.
Plunger
Moves reciprocally to draw and compress fuel.
Delivery Valve
Stops the reverse flow of fuel pumped to the rail.
Cylinder Recognition Sensor {TDC Identifies the engine cylinders.
(G) Sensor}
Feed Pump
• The feed pump, which is integrated in the supply pump, draws fuel from the fuel tank and feeds it to the
pump chamber via the fuel filter. There are two types of feed pumps, the trochoid type and the vane type.
Trochoid Type
9 The camshaft actuates the outer/inner rotors of the feed pump, causing them to start rotating. In accordance with the space produced by the movement of the outer/inner rotors, the feed pump draws fuel
into the suction port and pumps fuel out the discharge port.
Outer Rotor
Suction Port
To Pump Chamber
Discharge Port
Inner Rotor
From Fuel Tank
Q000770E
1– 18
Operation Section
Vane Type
9 The camshaft actuates the feed pump rotor and the vanes slide along the inner circumference of the
eccentric ring. Along with the rotation of the rotor, the pump draws fuel from the fuel tank, and discharges it to the SCV and the pumping mechanism.
Discharge Port
Rotor
Eccentric Ring
Suction Port
Vane
Q000771E
PCV: Pump Control Valve
• The PCV (Pump Control Valve) regulates the fuel discharge quantity from the supply pump in order to
regulate the rail pressure. The fuel quantity discharged from the supply pump to the rail is determined by
the timing with which the current is applied to the PCV.
Actuation Circuit
9 The diagram below shows the actuation circuit of the PCV. The ignition switch turns the PCV relay ON
and OFF to apply current to the PCV. The ECU handles ON/OFF control of the PCV. Based on the
signals from each sensor, it determines the target discharge quantity required to provide optimum rail
pressure and controls the ON/OFF timing for the PCV to achieve this target discharge quantity.
From PCV relay
PCV
To Rail
PCV Relay
Ignition Switch
+B
PCV1
PCV2
Q000772E
Operation Section
1– 19
Pumping Mechanism
• The camshaft is actuated by the engine and the cam actuates the plunger via the tappet to pump the fuel
sent by the feed pump. The PCV controls the discharge quantity. The fuel is pumped from the feed pump
to the cylinder, and then to the delivery valve.
PCV (Pump Control Valve)
Delivery Valve
To Rail
Plunger
Camshaft
Feed Pump
Pulsar for TDC (G) Sensor
Cam (3 Lobes: 6-Cylinders)
Q000773E
1– 20
Operation Section
CYLINDER RECOGNITION SENSOR {TDC (G) SENSOR}
• The cylinder recognition sensor {TDC (G) sensor} uses the alternating current voltage generated by the
change in the lines of magnetic force passing through the coil to send the output voltage to the ECU. This
is the same for the engine speed sensor installed on the engine side. A disc-shaped gear, which is provided in the center of the supply pump camshaft, has cutouts that are placed at 120? intervals, plus an
extra cutout. Therefore, this gear outputs seven pulses for every two revolutions of the engine (for a sixcylinder engine). Through the combination of engine-side engine speed pulses and TDC pulses, the pulse
after the extra cutout pulse is recognized as the No. 1 cylinder.
· For a 6-Cylinder Engine (Reference)
Cylinder Recognition Sensor
(TDC (G) Sensor)
No.1 Cylinder TDC (G) Pulse
· TDC (G) Pulse
No.6 Cylinder TDC (G) Standard Pulse
No.1 Cylinder Recognition TDC (G) Pulse
· Engine Speed Pulse
0 2 4 6 8 101214 0 2 4 6 810 1214 0 2 4 6 8 1012
No.1 Cylinder Engine Speed Standard Pulse
0 2 4 6 8 101214 0 2 4 6 8 101214 0 2 4 6 8 1012
No.6 Cylinder Engine Speed Standard Pulse
0 2 4 6 8
Q000774E
Operation Section
1– 21
(4) Supply Pump Operation
Supply Pump Overall Fuel Flow
• The fuel is drawn by the feed pump from the fuel tank and sent to the pumping mechanism via the PCV.
The PCV adjusts the quantity of fuel pumped by the pumping mechanism to the necessary discharge
quantity, and the fuel is pumped to the rail via the delivery valve.
Fuel Discharge Quantity Control
• The fuel sent from the feed pump is pumped by the plunger. In order to adjust the rail pressure, the PCV
controls the discharge quantity. Actual operation is as follows.
PCV and Plunger Operation During Each Stroke
Intake Stroke (A)
In the plunger's descent stroke, the PCV opens and low-pressure fuel is suctioned into
the plunger chamber via the PCV.
Pre-Stroke (B)
Even when the plunger enters its ascent stroke, the PCV remains open while it is not
energized. During this time, fuel drawn in through the PCV is returned through the PCV
without being pressurized (pre-stroke).
Pumping
Stroke At a timing suited to the required discharge quantity, power is supplied to close the
(C)
PCV, the return passage closes, and pressure in the plunger chamber rises. Therefore,
the fuel passes through the delivery valve (reverse cut-off valve) and is pumped to the
rail. Specifically, the plunger lift portion after the PCV closes becomes the discharge
quantity, and by varying the timing for the PCV closing (the end point of the plunger
pre-stroke), the discharge quantity is varied to control the rail pressure.
Intake Stroke (A)
When the cam exceeds the maximum lift, the plunger enters its descent stroke and
pressure in the plunger chamber decreases. At this time, the delivery valve closes and
fuel pumping stops. In addition, the PCV opens because it is de-energized, and lowpressure fuel is suctioned into the plunger chamber. Specifically, the system goes into
state A.
Intake Stroke
Discharge Quantity
Q=
Pumping Stroke
d 2 (H-h)
4
Cam Lift
h
H
Pre-Stroke
Open Valve
PCV Operation
Close Valve
When Discharge When Discharge
Quantity Increases Quantity Decreases
Pumping the Required
Discharge Quantity
Pump Operation
PCV
Return
From Fuel Tank
To Rail
Pumping
Mechanism
Delivery Valve
Plunger
d
(A)
(B)
(C)
(A')
Q000775E
1– 22
Operation Section
3.2 HP2 Type
(1) Construction and Characteristics
• The supply pump is primarily composed of the two pumping mechanism (inner cam, roller, two plungers)
systems, the SCV (Suction Control Valve), the fuel temperature sensor, and the feed pump (vane type),
and is actuated with half the engine rotation.
• The pumping mechanism consists of an inner cam and a plunger, and forms a tandem configuration in
which two systems are arranged axially. This makes the supply pump compact and reduces the peak
torque.
• The quantity of fuel discharged to the rail is controlled by the fuel suction quantity using SCV (Suction
Control Valve) control. In order to control the discharge quantity with the suction quantity, excess pumping
operations are eliminated, reducing the actuation load and suppressing the rise in fuel temperature.
Fuel Temperature Sensor
Delivery Valve
Overflow
SCV
(Suction Control
Valve)
Fuel Suction (From Fuel Tank)
Regulating Valve
Feed Pump
Check Valve
Roller
Plunger
Inner Cam
Q000818E
Operation Section
1– 23
(2) Supply Pump Actuating Torque
• Because the pumping mechanism is a tandem configuration, its peak actuating torque is one-half that of
a single pump with the same discharge capacity.
Tandem Type
Single Type
Pumping
Pumping
Plunger 1
Composition
Plunger 2
Feed
Pumping
Suction
Torque (Oil Pumping Rate)
Torque (Oil Pumping Rate)
Torque Pattern
Feed
Pumping
Solid Line : Plunger 1
Broken Line: Plunger 2
Q000819E
1– 24
Operation Section
(3) Exploded View
Regulating Valve
Fuel Temperature Sensor
Camshaft
Inner Cam
Roller
Pump Body
Feed Pump
Shoe
Delivery Valve
SCV (Suction Control Valve)
Check Valve
Q000820E
Operation Section
1– 25
(4) Component Part Functions
Component Parts
Functions
Feed Pump
Draws fuel from the fuel tank and feeds it to the pumping mechanism.
Regulating Valve
Regulates internal fuel pressure in the supply pump.
SCV (Suction Control Valve)
Controls the quantity of fuel that is fed to the plunger in order to control fuel pressure in the rail.
Pumping
Inner Cam
Actuates the plunger.
Mechanism
Roller
Actuates the plunger.
Plunger
Moves reciprocally to draw and compress fuel.
Delivery Valve
Maintains high pressure by separating the pressurized area (rail) from
the pumping mechanism.
Fuel Temperature Sensor
Detects the fuel temperature.
Check Valve
Prevents the pressurized fuel in the pumping mechanism from flowing
back into the suction side.
Feed Pump
• The feed pump is a four-vaned type that draws fuel from the fuel tank and discharges it to the pumping
mechanism. The rotation of the drive shaft causes the feed pump rotor to rotate and the vane to move by
sliding along the inner surface of the casing (eccentric ring). Along with the rotation of the rotor, the pump
draws fuel from the fuel tank, and discharges it to the SCV and the pumping mechanism. To keep the
vane pressed against the inner circumference, a spring is provided inside each vane, in order to minimize
fuel leakage within the pump.
Eccentric Ring
Spring
Rotor
Vane
Front Cover
Rear Cover
Q000821E
Operation Section
Regulating Valve
• The purpose of the regulating valve is to control the feed pressure (fuel pumping pressure) sending fuel
to the pumping mechanism. As the rotational movement of the pump increases and the feed pressure
exceeds the pressure set at the regulating valve, the valve opens by overcoming the spring force, allowing the fuel to return to the suction side.
Regulating Valve
Suction Inlet
Regulating Valve Body
Filter
Spring
Piston
Feed Pump
(Discharge Side)
Regulating Valve
Open Valve Pressure Characteristic
Feed Pressure
(Pumping Pressure)
1– 26
Open Valve
Pressure High
Open Valve
Pressure Low
Speed
Feed Pump
(Suction Side)
Bushing
Q000822E
SCV: Suction Control Valve
• A solenoid type valve has been adopted. The ECU controls the duration of the current applied to the SCV
in order to control the quantity of fuel drawn into the pumping mechanism. Because only the quantity of
fuel required to achieve the target rail pressure is drawn in, the actuating load of the supply pump decreases, thus improving fuel economy.
Stopper
Coil
Needle Valve
Spring
Q000823E
Operation Section
1– 27
SCV ON
9 When current is applied to the coil, it pulls the needle valve upward, allowing fuel to be drawn into the
pumping mechanism of the supply pump.
To Pump Pumping Mechanism
From Feed Pump
Q000824E
SCV OFF
9 When current is no longer applied to the coil, the needle valve closes and stops the suction of fuel.
From Feed Pump
Q000825E
1– 28
Operation Section
Pumping Mechanism (Plunger, Inner Cam, Roller)
• The pumping mechanism is made up of the plunger, inner cam, and roller, and it draws in the fuel discharged by the feed pump and pumps it to the rail. Because the drive shaft and the inner cam have an
integral construction, the rotation of the drive shaft directly becomes the rotation of the inner cam.
• Two plunger systems are arranged in series (tandem type) inside the inner cam. Plunger 1 is situated
horizontally, and plunger 2 is situated vertically. Plunger 1 and plunger 2 have their suction and compression strokes reversed (when one is on the intake, the other is discharging), and each plunger discharges
twice for each one rotation, so for one rotation of the supply pump, they discharge a total of four times to
the rail.
Plunger 1
(Horizontal)
Plunger 2
(Vertical)
Plunger Length Combination
· Plunger 1: Medium + Medium
· Plunger 2: Short + Long
Roller
Roller Diameter: 9
Roller Length: 21mm
Material: Reinforced Ceramic
Inner Cam
(Cam Lift: 3.4mm)
Plunger 1
Cam 90 Rotation
Plunger 2
Plunger 1: Start of Suction
Plunger 2: Start of Pumping
Plunger 1: Start of Pumping
Plunger 2: Start of Suction
Q000826E
Operation Section
1– 29
Delivery Valve
• The delivery valve, which contains two valve balls, delivers the pressurized fuel from plungers 1 and 2 to
the rail in alternating strokes. When the pressure in the plunger exceeds the pressure in the rail, the valve
opens to discharge fuel.
From Plunger 1
To Rail
From Plunger 2
Pin
Gasket
Guide
Stopper
Valve Ball
· When Plunger 1 Pumping
Holder
· When Plunger 2 Pumping
Q000827E
Fuel Temperature Sensor
• The fuel temperature sensor is installed on the fuel intake side and utilizes the characteristics of a thermistor in which the electric resistance changes with the temperature in order to detect the fuel temperature.
Resistance Value
Thermistor
Resistance - Temperature
Characteristic
Temperature
Q000828E
Check Valve
• The check valve, which is located between the SCV (Suction Control Valve) and the pumping mechanism, prevents the pressurized fuel in the pumping mechanism from flowing back into the SCV.
Pump Housing
Spring
Valve
To Pumping Mechanism
Stopper
To SCV
Plug
Q000829E
1– 30
Operation Section
Check Valve Open
9 During fuel suction (SCV ON), the feed pressure opens the valve, allowing fuel to be drawn into the
pumping mechanism.
To Pumping Mechanism
From SCV
Q000830E
Check Valve Closed
9 During fuel pumping (SCV OFF), the pressurized fuel in the pumping mechanism closes the valve, preventing fuel from flowing back into the SCV.
From Pumping Mechanism
Q000831E
Operation Section
1– 31
(5) Supply Pump Operation
Supply Pump Overall Fuel Flow
• Fuel is suctioned by the feed pump from the fuel tank and sent to the SCV. At this time, the regulating
valve adjusts the fuel pressure to below a certain level. Fuel sent to the feed pump has the required discharge quantity adjusted by the SCV and enters the pumping mechanism through the check valve. The
fuel pumped by the pumping mechanism is pumped through the delivery valve to the rail.
Overflow Orifice
Regulating Valve
To Tank
From Fuel Tank
Delivery Valve
To Rail
Cam
SCV1
Check Valve 1
Check Valve 2
Head
SCV2
Feed Pump
Plunger
Q000832E
1– 32
Operation Section
Fuel Discharge Quantity Control
• The diagram below shows that the suction starting timing (SCV (Suction Control Valve) ON) is constant
(determined by the pump speed) due to the crankshaft position sensor signal. For this reason, the fuel
suction quantity is controlled by changing the suction ending timing (SCV OFF). Hence, the suction quantity decreases when the SCV is turned OFF early and the quantity increases when the SCV is turned OFF
late.
• During the intake stroke, the plunger receives the fuel feed pressure and descends along the cam surface. When the SCV turns OFF (suction end), the feed pressure on the plunger ends and the descent
stops. Since the suction quantity varies, when suction ends (except for maximum suction) the roller separates from the cam surface.
• When the drive shaft rotates and the cam peak rises and the roller comes in contact with the cam surface
again, the plunger is pressed by the cam and starts pumping. Since the suction quantity = the discharge
quantity, the discharge quantity is controlled by the timing with which the SCV is switched OFF (suction
quantity).
360 CR
Crankshaft
Angle
TDC #3
TDC #1
Compression
Top Dead Center
TDC #2
TDC #4
Cylinder Recognition
Sensor Signal
0 2 4 6 8 101214 16 0 2 4 6 8 101214
Crankshaft Position
Sensor Signal
SCV 1
ON
OFF
SCV 2
ON
OFF
Suction
Suction
0 2 4 6 8 101214 16 0 2 4 6 8 101214
Increased Suction
Quantity
Suction
Decreased Suction Suction
Quantity
Delivery Valve
Discharge
Horizontal
Cam Lift
Pumping Suction
Pumping Suction
Vertical
Cam Lift
Pumping Suction
Fuel
Fuel
SCV
OFF
ON
Check Valve
Pumping Suction
OFF
OFF
Fuel
Plunger
Delivery Valve
Roller
Suction
Start of Suction
End of Suction
Pumping
Start of Pumping
End of Pumping
Q000833E
Operation Section
1– 33
3.3 HP3 Type
(1) Construction and Characteristics
• The supply pump is primarily composed of the pump unit (eccentric cam, ring cam, two plungers), the
SCV (suction control valve), the fuel temperature sensor and the feed pump (trochoid type), and is actuated at 1/1 or 1/2 the engine rotation.
• The two compact pump unit plungers are positioned symmetrically above and below on the outside of the
ring cam.
• The fuel discharge quantity is controlled by the SCV, the same as for the HP2, in order to reduce the actuating load and suppress the rise in fuel temperature. In addition, there are two types of HP3 SCV: the
normally open type (the suction valve opens when not energized) and the normally closed type (the suction valve is closed when not energized).
• With a DPNR system (Diesel Particulate NOx Reduction) system, there is also a flow damper. The purpose of this flow damper is to automatically shut off the fuel if a leak occurs in the fuel addition valve passage within the DPNR.
Suction Valve
Plunger
Feed Pump
Ring Cam
SCV (Suction Control Valve)
Fuel Temperature Sensor
Delivery Valve
Q000835E
1– 34
Operation Section
(2) Exploded View
Delivery Valve
Element Sub-Assembly
Delivery Valve
Fuel Temperature Sensor
Plunger
Feed Pump
Regulating Valve
SCV
(Suction Control Valve)
Ring Cam
Pump Housing
Plunger
Eccentric Cam
Camshaft
Delivery Valve
Element Sub-Assembly
Q000836E
Operation Section
1– 35
(3) Component Part Functions
Component Parts
Functions
Feed Pump
Draws fuel from the fuel tank and feeds it to the plunger.
Regulating Valve
Regulates the pressure of the fuel in the supply pump.
SCV (Suction Control Valve)
Controls the quantity of fuel that is fed to the plungers.
Pump Unit
Eccentric Cam
Actuates the ring cam.
Ring Cam
Actuates the plunger.
Plunger
Moves reciprocally to draw and compress fuel.
Delivery Valve
Prevents reverse flow from the rail of the fuel pumped from the
plunger.
Fuel Temperature Sensor
Detects the fuel temperature.
Feed Pump
• The trochoid type feed pump, which is integrated in the supply pump, draws fuel from the fuel tank and
feeds it to the two plungers via the fuel filter and the SCV (Suction Control Valve). The drive shaft actuates
the outer/inner rotors of the feed pump, thus causing the rotors to start rotating. In accordance with the
space that increases and decreases with the movement of the outer and inner rotors, the feed pump
draws fuel into the suction port and pumps fuel out the discharge port.
Outer Rotor
To Pump Chamber
Discharge Port
Suction Port
Inner Rotor
From Fuel Tank
Q000770E
Regulating Valve
• The regulating valve keeps the fuel feed pressure (discharge pressure) below a certain level. If the pump
speed increases and the feed pressure exceeds the preset pressure of the regulating valve, the valve
opens by overcoming the spring force in order to return the fuel to the suction side.
Pump Housing
Bushing
Piston
Feed Pump
Spring
SCV
Plug
Q000837E
1– 36
Operation Section
Suction Control Valve (SCV)
• In contrast to the HP2, the SCV for the HP3 supply pump is equipped with a linear solenoid valve. The
fuel flow volume supplied to the high-pressure plunger is controlled by adjusting the engine ECU supplies
power to the SCV (duty ratio control). When current flows to the SCV, the internal armature moves according to the duty ratio. The armature moves the needle valve, controlling the fuel flow volume according
to the amount that the valve body fuel path is blocked. Control is performed so that the supply pump suctions only the necessary fuel quantity to achieve the target rail pressure. As a result, the supply pump
actuation load is reduced.
• There are two types of HP3 SCV: the normally open type (the suction valve opens when not energized)
and the normally closed type (the suction valve is closed when not energized). The operation of each type
is the reverse of that of the other.
• In recent years, a compact SCV has been developed. Compared to the conventional SCV, the position
of the return spring and needle valve in the compact SCV are reversed. For this reason, operation is also
reversed.
Normally Open Type
9 When the solenoid is not energized, the return spring pushes against the needle valve, completely
opening the fuel passage and supplying fuel to the plungers. (Total quantity suctioned → Total quantity
discharged)
9 When the solenoid is energized, the armature pushes the needle valve, which compresses the return
spring and closes the fuel passage. In contrast, the needle valve in the compact SCV is pulled upon,
which compresses the return spring and closes the fuel passage.
9 The solenoid ON/OFF is actuated by duty ratio control. Fuel is supplied in an amount corresponding to
the open surface area of the passage, which depends on the duty ratio, and then is discharged by the
plungers.
Return Spring
Conventional SCV
External View
Solenoid
Valve Body
Needle Valve
Cross Section
Q002340E
Solenoid
Compact SCV
Valve Body
Return Spring
Needle Valve
External View
Cross Section
Q002309E
Operation Section
1– 37
Duty Ratio Control
9 The engine ECU outputs sawtooth wave signals with a constant frequency. The value of the current is
the effective (average) value of these signals. As the effective value increases, the valve opening decreases, and as the effective value decreases, the valve opening increases.
High Suction Quantity
ON
OFF
Current
Actuating Voltage
Low Suction Quantity
Average Current Difference
QD0710E
When the SCV Energized Duration (Duty ON Time) is Short
9 When the SCV energization time is short, the average current flowing through the solenoid is small. As
a result, the needle valve is returned by spring force, creating a large valve opening. Subsequently, the
fuel suction quantity increases.
Conventional SCV
Feed Pump
Large Valve
Opening
SCV
Needle
Valve
Q002341E
1– 38
Operation Section
Compact SCV
Feed Pump
Needle Valve
Large
Opening
Q002321E
When the SCV Energized Duration (Duty ON Time) is Long
9 When the energization time is long, the average current flowing to the solenoid is large. As a result, the
needle valve is pressed out (in the compact SCV, the needle valve is pulled), creating a small valve
opening. Subsequently, the fuel suction quantity decreases.
Conventional SCV
Feed Pump
Small
Opening
SCV
Needle
Valve
Q002342E
Operation Section
1– 39
Compact SCV
Feed Pump
Needle Valve
SCV
Small Valve
Opening
Q002322E
Operation Section
1– 40
Normally Closed Type
9 When the solenoid is energized, the needle valve is pressed upon (in the compact SCV, the cylinder is
pulled upon) by the armature, completely opening the fuel passage and supplying fuel to the plunger.
(Total quantity suctioned → Total quantity discharged)
9 When power is removed from the solenoid, the return spring presses the needle valve back to the original position, closing the fuel passage.
9 The solenoid ON/OFF is actuated by duty ratio control. Fuel is supplied in an amount corresponding to
the open surface area of the passage, which depends on the duty ratio, and then is discharged by the
plungers.
Return Spring
Conventional SCV
Needle Valve
External View
Solenoid
Valve Body
Cross Section
Valve Body
Compact SCV
Q002343E
Solenoid
Return Spring
Needle Valve
External View
Cross Section
Q002323E
Duty Ratio Control
9 The engine ECU outputs sawtooth wave signals with a constant frequency. The value of the current is
the effective (average) value of these signals. As the effective value increases, the valve opening increases, and as the effective value decreases, the valve opening decreases.
Current
Actuating Voltage
High Suction Quantity
Low Suction Quantity
ON
OFF
Average Current Difference
Q000844E
Operation Section
1– 41
When the SCV Energized Duration (Duty ON Time) is Long
9 When the energization time is long, the average current flowing to the solenoid is large. As a result, the
needle valve is pushed out (in the compact SCV, the needle valve is pulled), creating a large valve
opening. Subsequently, the fuel suction quantity increases.
Conventional SCV
Feed Pump
Needle
Valve
SCV
Large
Opening
Q002344E
Compact SCV
SCV
Feed Pump
Large Valve
Opening
Needle
Valve
Q002324 E
1– 42
Operation Section
When the SCV Energized Duration (Duty ON Time) is Short
9 When the energization time is short, the average current flowing through the solenoid is small. As a
result, the needle valve is returned to the original position by spring force, creating a small valve opening. Subsequently, the fuel suction quantity decreases.
Conventional SCV
Feed Pump
Needle
Valve
SCV
Small
Opening
Q002345E
Compact SCV
Feed Pump
Small Valve
Opening
SCV
Needle
Valve
Q002325E
Operation Section
1– 43
Pump Unit (Eccentric Cam, Ring Cam, Plunger)
• The eccentric cam is attached to the camshaft and the ring cam is installed on the eccentric cam. There
are two plungers at positions symmetrical above and below the ring cam.
Ring Cam
Plunger A
Camshaft
Feed Pump
Eccentric Cam
Plunger B
Q000845E
• Because the rotation of the camshaft makes the eccentric cam rotate eccentrically, the ring cam follows
this and moves up and down, and this moves the two plungers reciprocally. (The ring cam itself does not
rotate.)
Eccentric Cam
Ring Cam
Camshaft
Q000846E
1– 44
Operation Section
Delivery Valve
• The delivery valve for the HP3 has an integrated element and is made up of the check ball, spring, and
holder. When the pressure at the plunger exceeds the pressure in the rail, the check ball opens to discharge the fuel.
Element
Check Ball
Spring
Holder
Plunger
Q000847E
Fuel Temperature Sensor
• The fuel temperature sensor is installed on the fuel intake side and utilizes the characteristics of a thermistor in which the electric resistance changes with the temperature in order to detect the fuel temperature.
Resistance - Temperature
Characteristic
Resistance Value
Thermistor
Temperature
Q000848E
Operation Section
1– 45
(4) Supply Pump Operation
Supply Pump Overall Fuel Flow
• The fuel is suctioned by the feed pump from the fuel tank and sent to the SCV. At this time, the regulating
valve adjusts the fuel pressure to below a certain level. The fuel sent from the feed pump has the required
discharge quantity adjusted by the SCV, and enters the pump unit through the suction valve. The fuel
pumped by the pump unit is pumped through the delivery valve to the rail.
Inject
Rail
Discharge Valve
From Pump
Suction Pressure
Feed Pressure
High Pressure
Return Pressure
Suction Valve
Plunger
Return Spring
To Rail
Return
Combustion Overflow
Regulating Valve
Filter
Camshaft
Feed Pump
Fuel Intake Port
Suction
Fuel Filter
(With Priming Pump)
Fuel Tank
Q000849E
1– 46
Operation Section
Operation
• The discharge quantity is controlled by SCV control, the same as for the HP2, however it differs from the
HP2 in that the valve opening is adjusted by duty ratio control.
• In the intake stroke, the spring makes the plunger follow the movement of the ring cam, so the plunger
descends together with the ring cam. Thus, unlike the HP2, the plunger itself also suctions in fuel. When
the suctioned fuel passes through the SCV, the flow quantity is controlled to the required discharge quantity by the valve opening and enters the pump main unit.
• The quantity of fuel adjusted by the SCV is pumped during the pumping stroke.
Suction Valve
Plunger A
Delivery Valve
Eccentric Cam
Ring Cam
SCV
Plunger B
Plunger A: End of Compression
Plunger A: Start of Suction
Plunger B: End of Suction
Plunger B: Start of Compression
Plunger A: Start of Compression
Plunger A: End of Suction
Plunger B: Start of Suction
Plunger B: End of Compression
QD0707E
Operation Section
1– 47
3.4 HP4 Type
(1) Construction and Characteristics
• The HP4 basic supply pump construction is the same as for the HP3. The composition is also the same
as the HP3, being made up of the pump unit (eccentric cam, ring cam, plunger), the SCV (suction control
valve), the fuel temperature sensor, and the feed pump. The main difference is that there are three plungers.
• Because there are three plungers, they are positioned at intervals of 120? around the outside of the ring
cam. In addition, the fuel delivery capacity is 1.5 times that of the HP3.
• The fuel discharge quantity is controlled by the SCV, the same as for the HP3.
SCV (Suction Control Valve)
Fuel Temperature Sensor
Delivery Valve
Feed Pump
Plunger
Eccentric Cam
Suction Valve
Q000850E
1– 48
Operation Section
(2) Exploded View
SCV
IN
Filter
Fuel Temperature Sensor
Feed Pump
Regulating Valve
OUT
Pump Body
Ring Cam
Camshaft
Q000457E
Operation Section
1– 49
(3) Component Part Functions
Component Parts
Functions
Feed Pump
Draws fuel from the fuel tank and feeds it to the plunger.
Regulating Valve
Regulates the pressure of the fuel in the supply pump.
SCV (Suction Control Valve)
Controls the quantity of fuel that is fed to the plungers.
Pump Unit
Eccentric Cam
Actuates the ring cam.
Ring Cam
Actuates the plunger.
Plunger
Moves reciprocally to draw and compress fuel.
Suction Valve
Prevents reverse flow of compressed fuel into the SCV.
Delivery Valve
Prevents reverse flow from the rail of the fuel pumped from the
plunger.
Fuel Temperature Sensor
Detects the fuel temperature.
• The HP4 supply pump component parts and functions are basically the same as for the HP3. The explanations below only cover those points on which the HP4 differs from the HP3. For other parts, see the
appropriate item in the explanation of the HP3.
Pump Unit (Eccentric Cam, Ring Cam, Plunger)
• A triangular ring cam is installed on the eccentric cam on the drive shaft, and three plungers are installed
to the ring cam at intervals of 120°.
Plunger
Camshaft
Eccentric Cam
Ring Cam
Q000851E
1– 50
Operation Section
• Because the rotation of the camshaft makes the eccentric cam rotate eccentrically, the ring cam follows this and this
moves the three plungers reciprocally. (The ring cam itself does not rotate.)
Ring Cam
Plunger #1
Plunger #2
End of Pumping
Pumping
Eccentric Cam
Camshaft
Rotate 120 Clockwise
Camshaft
Camshaft
Rotate 120 Clockwise
Suction
Plunger #3
Pumping
Suction
Suction
End of Pumping
Camshaft
Rotate 120 Clockwise
End of Pumping
Pumping
D000852E
Operation Section
1– 51
(4) Supply Pump Operation
Supply Pump Overall Fuel Flow
• The fuel is suctioned by the feed pump from the fuel tank and sent to the SCV. At this time, the regulating
valve adjusts the fuel pressure to below a certain level. The fuel sent from the feed pump has the required
discharge quantity adjusted by the SCV, and enters the pump unit through the suction valve. The fuel
pumped by the pump unit is pumped through the delivery valve to the rail.
Feed Pump from Fuel Tank (Suction)
SCV from Feed Pump (Low Pressure)
Pump Unit from SCV (Low-Pressure Adjustment Complete)
From Pump Unit to Rail (High Pressure)
SCV
Camshaft
To Rail
From Fuel
Tank
Feed Pump
Ring Cam
Plunger
Delivery Valve
Suction Valve
Q000853E
Operation
• The discharge quantity is controlled by the SCV. As with the HP3, the valve opening is adjusted by duty
ratio control. The only difference from the HP3 is the shape of the pump unit. Operation and control are
basically the same. For details on operation and control, see the explanation of the HP3.
1– 52
Operation Section
4. RAIL DESCCRIPTION
4.1 Rail Functions and Composition
z The function of the rail is to distribute fuel pressurized by the supply pump to each cylinder injector.
z The shape of the rail depends on the model and the component parts vary accordingly.
z The component parts are the rail pressure sensor (Pc sensor), pressure limiter, and for some models a flow
damper and pressure discharge valve.
Pressure Limiter
Flow Damper
Rail
Rail Pressure Sensor (Pc Sensor)
Pressure Discharge Valve
Rail
Pressure Limiter
Rail Pressure Sensor (Pc Sensor)
Q000854E
Operation Section
1– 53
4.2 Component Part Construction and Operation
Component Parts
Rail
Functions
Stores pressurized fuel that has been pumped from the supply pump and
distributes the fuel to each cylinder injector.
Pressure Limiter
Opens the valve to release pressure if the pressure in the rail becomes
abnormally high.
Rail Pressure Sensor (Pc Sen- Detects the fuel pressure in the rail.
sor)
Flow Damper
Reduces the pressure pulsations of fuel in the rail. If fuel flows out excessively, the damper closes the fuel passage to prevent further flow of fuel.
Mostly used with engines for large vehicles.
Pressure Discharge Valve
Controls the fuel pressure in the rail. Mostly used with engines for passenger cars.
(1) Pressure Limiter
• The pressure limiter opens to release the pressure if abnormally high pressure is generated. If pressure
within the rail becomes abnormally high, the pressure limiter operates (opens). It resumes operation
(closes) after the pressure falls to a certain level. Fuel released by the pressure limiter returns to the fuel
tank.
[ REFERENCE ]
The operating pressures for the pressure limiter depend on the vehicle model and are approximately 140230MPa for the valve opening pressure, and approximately 30-50MPa for the valve closing pressure.
Pressure Limiter
Leak
(To Fuel Tank)
Abnormally High Pressure
Valve Open
Valve Close
Return
Rail Pressure
Q000855E
1– 54
Operation Section
(2) Rail Pressure Sensor (Pc Sensor)
• The rail pressure sensor (Pc sensor) is installed on the rail. It detects the fuel pressure in the rail and
sends a signal to the engine ECU. This is a semi-conductor sensor that uses the piezo-electric effect of
the electrical resistance varying when pressure is applied to a silicon element.
Output - Common Rail
Voltage Pressure Characteristic
Sensor Wiring Diagram
Pc
Vout
Vout
ECU
GND
GND
Vout
Vcc=5V
+5V
Output Voltage
Vcc
Vcc
Rail Pressure
Q000856E
• There are also rail pressure sensors that have dual systems to provide a backup in case of breakdown.
Pc
Sensors
VC
VCS
+5V
Vout/Vcc
PR
PR2
ECU
ECU
E2
E2S
VC
PR
E2
Vcc=5V
Output Voltage 2
E2S PR2 VCS
Output Voltage 1
The output voltage is offset.
Rail Pressure
Q000857E
(3) Flow Damper
• The flow damper reduces the pressure pulsations of the fuel in the pressurized pipe and supplies fuel to
the injectors at a stabilized pressure. The flow damper also presents abnormal discharge of fuel by shutting off the fuel passage in the event of excess fuel discharge, for example due to fuel leaking from an
injection pipe or injector. Some flow dampers combine a piston and ball, and some have only a piston.
Type Combining Piston and Ball
Piston
Ball
Seat
Piston-Only Type
Piston
Spring
Seat
Spring
Q000858E
Operation Section
1– 55
Operation of Piston-and-Ball Type
9 When a pressure pulse occurs in a high-pressure pipe, the resistance of it passing through the orifice
disrupts the balance between the rail side and injector side pressures, so the piston and ball move to
the injector side, absorbing the pressure pulse. With normal pressure pulses, since the rail side and
injector side pressures are soon balanced, the piston and ball are pushed back to the rail side by the
spring. If there is an abnormal discharge, for example due to an injector side fuel leak, the amount of
fuel passing through the orifice cannot be balanced out and the piston presses the ball against the seat,
so the passage for fuel to the injector is shut off.
· During Pressure Pulse Absorption
Piston
· Fuel Cut-Off
Ball
Spring
Seat
Q000859E
Operation of Piston-Only Type
9 The piston contacts the seat directly and the piston shuts off the fuel passage directly. Operation is the
same as for the piston-and-ball type.
· During Pressure Pulse Absorption
Piston
· Fuel Cut-Off
Seat
Spring
Q000860E
1– 56
Operation Section
(4) Pressure Discharge Valve
• The pressure discharge valve controls the fuel pressure in the rail. When rail fuel pressure exceeds the
target injection pressure, or when the engine ECU judges that rail fuel pressure exceeds the target value,
the pressure discharge valve solenoid coil is energized. This opens the pressure discharge valve passage, allowing fuel to leak back to the fuel tank, and reducing rail fuel pressure to the target pressure.
Solenoid Coil
Pressure Discharge Valve
Rail
Operating
ON
ECU
To Fuel tank
Q000861E
Operation Section
1– 57
5. INJECTOR DESCRIPTION
5.1 General Description
z The injector injects the pressurized fuel in the rail into the engine combustion chamber at the optimal injection timing, injection quantity, injection rate, and injection pattern, in accordance with signals from the ECU.
z Injection is controlled using a TWV (Two-Way Valve) and orifice. The TWV controls the pressure in the control chamber to control the start and end of injection. The orifice controls the injection rate by restraining the
speed at which the nozzle opens.
z The command piston opens and closes the valve by transmitting the control chamber pressure to the nozzle
needle.
z When the nozzle needle valve is open, the nozzle atomizes the fuel and injects it.
z There are three types of injectors: the X1, X2, and G2.
TWV
Rail Pressure Sensor
Orifice
ECU
Control Chamber Portion
Rail
Command Piston
Supply Pump
Nozzle Needle
Nozzle
Q000862E
Operation Section
1– 58
5.2 Injector Construction and Features
z The injector consists of a nozzle similar to the conventional "nozzle & nozzle holder", an orifice that controls
the injection rate, the command piston, and a TWV (two-way solenoid valve). The basic construction is the
same for the X1, X2, and G2 types.
(1) X1 Type
• Precision control is attained through electronic control of the injection. The TWV comprises two valves:
the inner valve (fixed) and the outer valve (movable).
Solenoid
TWV
Inner Valve
Outer Valve
Command Piston
Orifice 1
Orifice 2
Nozzle
Q000863E
Operation Section
1– 59
(2) X2 Type
• By reducing the injector actuation load, the injector has been made more compact and energy efficient,
and its injection precision has been improved. The TWV directly opens and closes the outlet orifice.
Hollow Screw with Damper
Solenoid
Valve
Control
Chamber
From Rail
O-ring
Command Piston
Nozzle Spring
Pressure Pin
Seat
Leak Passage
High-Pressure Fuel
Nozzle Needle
Q000864E
1– 60
Operation Section
(3) G2 Type
• To ensure high pressure, the G2 type has improved pressure strength, sealing performance and pressure
wear resistance. It also has improved high-speed operability, enabling higher-precision injection control
and multi-injection.
To Fuel Tank
Connector
Solenoid Valve
From Rail
Command Piston
Nozzle Spring
Pressure Pin
Nozzle Needle
Leak Passage
Seat
Q000865E
[ REFERENCE ]
Multi-injection means that for the purpose of reducing exhaust gas emissions and noise, the main injection
is accomplished with one to five injections of fuel without changing the injection quantity.
Injection Quantity
Example : Pattern with Five Injections
Main Injection
After-Injection
Pilot Injection Pre-Injection
Time
Post-Injection
Q000866E
Operation Section
1– 61
5.3 Injector Operation
z The injector controls injection through the fuel pressure in the control chamber. The TWV executes leak
control of the fuel in the control chamber to control the fuel pressure within the control chamber. The TWV
varies with the injector type.
Non-Injection
• When the TWV is not energized, the TWV shuts off the leak passage from the control chamber, so the
fuel pressure in the control chamber and the fuel pressure applied to the nozzle needle are both the same
rail pressure. The nozzle needle thus closes due to the difference between the pressure-bearing surface
area of the command piston and the force of the nozzle spring, and fuel is not injected. For the X1 type,
the leak passage from the control chamber is shut off by the outer valve being pressed against the seat
by the force of the spring, and the fuel pressure within the outer valve. For the X2/G2 types, the control
chamber outlet orifice is closed directly by the force of the spring.
Injection
• When TWV energization starts, the TWV valve is pulled up, opening the leak passage from the control
chamber. When this leak passage opens, the fuel in the control chamber leaks out and the pressure
drops. Because of the drop in pressure within the control chamber, the pressure on the nozzle needle
overcomes the force pressing down, the nozzle needle is pushed up, and injection starts. When fuel leaks
from the control chamber, the flow quantity is restricted by the orifice, so the nozzle opens gradually. The
injection rate rises as the nozzle opens. As current continues to be applied to the TWV, the nozzle needle
eventually reaches the maximum amount of lift, which results in the maximum injection rate. Excess fuel
is returned to the fuel tank through the path shown.
End of Injection
• When TWV energization ends, the valve descends, closing the leak passage from the control chamber.
When the leak passage closes, the fuel pressure within the control chamber instantly returns to the rail
pressure, the nozzle closes suddenly, and injection stops.
X2 · G2
Leak Passage
To Fuel Tank
Solenoid
TWV
X1
Actuating
Current
Inner
Valve
Actuating
Current
Outer Valve
Actuating
Current
TWV
Rail
Leak
Passage
Outlet Orifice
Control Outlet Orifice
Chamber
Pressure
Inlet Orifice
Control
Chamber
Pressure
Control
Chamber
Pressure
Command
Piston
Injection Rate
Injection Rate
Injection Rate
Nozzle
Non-Injection
Injection
End of Injection
Q000867E
1– 62
Operation Section
5.4 Injector Actuation Circuit
z In order to improve injector responsiveness, the actuation voltage has been changed to high voltage, speeding up both solenoid magnetization and the response of the TWV. The EDU or the charge circuit in the ECU
raises the respective battery voltage to approximately 110V, which is supplied to the injector by signal from
the ECU to actuate the injector.
EDU Actuation
EDU
Constant
Amperage Circuit
Charging Circuit
High Voltage
Generation Circuit
Injector
INJ#1 (No.1 Cylinder)
Actuating Current
IJt
INJ#2 (No.3 Cylinder)
ECU
INJ#3 (No.4 Cylinder)
Control
Circuit
IJf
INJ#4 (No.2 Cylinder)
ECU Direct Actuation
Common 2
Common 1
Injector
ECU
Constant
Amperage Circuit
Constant
Amperage Circuit
High Voltage Generation Circuit
2WV#1 (No.1 Cylinder)
Actuating Current
2WV#2 (No.5 Cylinder)
2WV#3 (No.3 Cylinder)
2WV#4 (No.6 Cylinder)
2WV#5 (No.2 Cylinder)
2WV#6 (No.4 Cylinder)
Q000868E
Operation Section
1– 63
5.5 Other Injector Component Parts
(1) Hollow Screw with Damper
• The hollow screw with damper enhances injection quantity accuracy, by reducing the back-pressure pulsations (pressure fluctuations) of the leak fuel. In addition, it minimizes the back-pressure dependence
(the effect of the pressure in the leak pipe changing the injection quantity even though the injection command is the same) of the fuel in the leak pipe.
Hollow Screw with Damper
O-ring
Damper
O-ring
To Fuel tank
Q000869E
(2) Connector with Correction Resistor
• The connector with correction resistor has a built-in correction resistor in the connector section to minimize injection quantity variation among the cylinders.
Correction Resistor Terminal
Solenoid Terminal
Q000870E
1– 64
Operation Section
(3) Injector with QR Codes
• QR (Quick Response) codes have been adopted to enhance correction precision. The QR code, which
contains the correction data of the injector, is written to the engine ECU. QR codes have resulted in a
substantial increase in the number of fuel injection quantity correction points, greatly improving injection
quantity precision.
· QR Code Correction Points (Example)
10EA01EB
13EA01EB
0300 0000
0000 BC
ID Codes
Pressure
Parameter
Injection Quantity
QR Codes
Actuating Pulse Width TQ
Q000871E
[ REFERENCE ]
QR codes are a new two-dimensional code that was developed by DENSO. In addition to injection quantity
correction data, the code contains the part number and the product number, which can be read at extremely high speeds.
Operation Section
1– 65
Handling Injectors with QR Codes (Reference)
9 Injectors with QR codes have the engine ECU recognize and correct the injectors, so when an injector
or the engine ECU is replaced, it is necessary to register the injector's ID code in the engine ECU.
Replacing the Injector
9 It is necessary to register the ID code of the injector that has been replaced in the engine ECU.
"No correction resistance, so no electrical recognition capability."
Spare Injector
Engine ECU
* Necessary to record the injector ID codes in the Engine ECU.
QD1536E
Replacing the Engine ECU
9 It is necessary to register the ID codes of all the vehicle injectors in the engine ECU.
"No correction resistance, so no electrical recognition capability."
Vehicle-Side Injector
Spare Engine ECU
* Necessary to record the injector ID codes in the Engine ECU.
Q000985E
1– 66
Operation Section
6. DESCRIPTION OF CONTROL SYSTEM COMPONENTS
6.1 Engine Control System Diagram (Reference)
Accelerator Position Sensor
Ignition Switch Signal
Starter Signal
Warm-Up Switch Signal
Vehicle Speed Signal
Supply Pump
PCV(HP0)
SCV(HP2·3·4)
TDC(G) Sensor
(HP0)
Engine ECU
Fuel Temperature
Sensor (HP2·3·4)
Charge
Circuit
EDU
Pressure Discharge Valve
Pressure Limiter
Rail
Flow Damper
(Large Vehicles)
Rail Pressure Sensor
Intake Air
Temperature
Sensor
Airflow Meter
(with Intake Air Temperature Sensor)
E-VRV for EGR
To Fuel Tank
Intake Air
Pressure Sensor
Fuel Temperature Sensor (HP0)
Injector
EGR Shut-Off VSV
Coolant Temperature Sensor
Cylinder Recognition Sensor
(TDC (G) Sensor: HP2, 3, 4)
Crankshaft Position Sensor
(Engine Speed Sensor)
Flywheel
Supply Pump
PCV
TDC (G) Sensor
Fuel Temperature Sensor
SCV
Fuel Temperature Sensor
SCV
SCV
Fuel Temperature Sensor
HP0
HP2
HP3
HP4
Q000874E
Operation Section
1– 67
6.2 Engine ECU (Electronic Control Unit)
z The engine ECU constantly ascertains the status of the engine through signals from the sensors, calculates
fuel injection quantities etc. appropriate to the conditions, actuates the actuators, and controls to keep the
engine in an optimal state. The injectors are actuated by either the EDU or the charge circuit in the engine
ECU. This actuation circuit depends on the specifications of the model it is mounted in. The ECU also has
a diagnosis function for recording system troubles.
Sensors
Engine ECU
Actuators
Actuation Circuit
EDU
or
Cylinder Recognition Sensor
(TDC (G) Sensor)
Charge Circuit
(Built into ECU)
Injector
Crankshaft Position Sensor
(Engine Speed Sensor)
Engine ECU
Supply Pump
(PCV : HP0, SCV : HP2 · HP3 · HP4)
Accelerator Position Sensor
Other Sensors
Other Actuators
Q000875E
1– 68
Operation Section
6.3 EDU (Electronic Driving Unit)
(1) General Description
• An EDU is provided to enable high-speed actuation of the injectors. The EDU has a high-voltage generation device (DC/DC converter) and supplies high voltage to the injectors to actuate the injectors at high
speed.
Actuation Signal
Actuation Output
ECU
Check Signal
EDU
Q000876E
(2) Operation
• The high-voltage generating device in the EDU converts the battery voltage into high voltage. The ECU
sends signals to terminals B through E of the EDU in accordance with the signals from the sensors. Upon
receiving these signals, the EDU outputs signals to the injectors from terminals H through K. At this time,
terminal F outputs the IJf injection verification signal to the ECU.
+B
COM
A
L
High Voltage
Generation Circuit
IJt#1
IJt#2
ECU
IJt#3
IJt#4
H
B
IJt#1
I
C
Control Circuit
IJt#2
J
D
IJt#3
K
E
IJt#4
IJf
F
G
M
GND
GND
Q000877E
Operation Section
1– 69
6.4 Various Sensors
Various Sensor Functions
Sensor
Functions
Crankshaft Position Sensor Detects the crankshaft angle and outputs the engine speed signal.
(Engine Speed Sensor)
Cylinder Recognition Sensor Identifies the cylinders.
(TDC (G) Sensor)
Accelerator Position Sensor
Detects the opening angle of the accelerator pedal.
Intake Air Temperature Sen- Detects the temperature of the intake air after it has passed through the tursor
bocharger.
Mass Airflow Meter
Detects the flow rate of the intake air. It also contains an intake air temperature sensor that detects the temperature of the intake air (atmospheric temperature).
Coolant Temperature Sensor
Detects the engine coolant temperature.
Fuel Temperature Sensor
Detects the fuel temperature.
Intake Air Pressure Sensor
Detects the intake air pressure.
Atmospheric Pressure Sen- Detects the atmospheric pressure.
sor
1– 70
Operation Section
(1) Crankshaft Position Sensor (Engine Speed Sensor) and Cylinder Recognition Sensor
{TDC (G) Sensor}
Crankshaft Position Sensor (Engine Speed Sensor)
• The crankshaft position sensor is installed near the crankshaft timing gear or the flywheel. The sensor
unit is a MPU (magnetic pickup) type. When the engine speed pulsar gear installed on the crankshaft
passes the sensor section, the magnetic field of the coil within the sensor changes, generating AC voltage. This AC voltage is detected by the engine ECU as the detection signal. The number of pulses for
the engine speed pulsar depends on the specifications of the vehicle the sensor is mounted in.
Cylinder Recognition Sensor {TDC (G) Sensor}
• The cylinder recognition sensor is installed on the supply pump unit for the HP0 system, but for the HP2,
HP3, or HP4 system, it is installed near the supply pump timing gear. Sensor unit construction consists
of the MPU type, which is the same as for the crankshaft position sensor, and the MRE (magnetic resistance element) type. For the MRE type, when the pulsar passes the sensor, the magnetic resistance
changes and the voltage passing through the sensor changes. This change in voltage is amplified by the
internal IC circuit and output to the engine ECU. The number of pulses for the TDC pulsar depends on
the specifications of the vehicle the sensor is mounted in.
Sensor Mounting Position (Reference)
Cylinder Recognition Sensor
(TDC (G) Sensor)
Pulsar
(Gearless Section)
Pulsar
For MPU
Type
Engine Speed Pulsar
For MRE
Type
TDC (G) Pulsar
Crankshaft Position Sensor
(Engine Speed Sensor)
External View of Sensor
NEShielded
TDC(G)- TDC(G)
Wire
NE+
Circuit Diagram
VCC
GND
TDC(G)
MPU
Type
TDC(G)
Crankshaft Position Sensor
(Engine Speed Sensor)
TDC (G) Input Circuit
VCC
TDC(G)
GND
MRE
Type
MPU Type
ECU
NE
MRE Type
Engine Speed
Input Circuit
Cylinder Recognition Sensor
(TDC (G) Sensor)
Pulse Chart (Reference)
360 CA
360 CA
Engine Speed
Pulse
MPU
Type
TDC (G)
Pulse
MRE
Type
0V
720 CA
Q000878E
Operation Section
1– 71
(2) Accelerator Position Sensor
• The accelerator position sensor converts the accelerator opening into an electric signal and outputs it to
the engine ECU. There are two types of accelerator position sensor: the hall element type and the contact
type. In addition, to provide backup in the event of breakdown, there are two systems and the output voltage is offset.
Hall Element Type
9 This sensor uses a hall element to generate voltage from change in the direction of the magnetic field.
A magnet is installed on the shaft that rotates linked with the accelerator pedal, and the rotation of this
shaft changes the magnetic field of the Hall element. The voltage generated by this change in the magnetic field is amplified by an amplifier and input to the engine ECU.
A-VCC
VACCP Output Voltage (V)
Amplifier No. 1
Magnets (Pair)
+5V
VACCP1
A-GND
A-VCC
+5V
VACCP2
A-GND
ECU
Accelerator Pedal
Amplifier No. 2
Hall Elements (2)
4
3
2
1
0
50
100
Accelerator Opening (%)
Q000879E
Contact Type
9 The sensor uses a contact-type variable resistor. Since the lever moves linked with the accelerator pedal, the sensor resistance value varies with the accelerator pedal opening. Therefore, the voltage passing the sensor changes, and this voltage is input to the engine ECU as the accelerator opening signal.
Accelerator Position Sensor
Accelerator Position Sensor Circuit Diagram
Fully Open
Fully
Closed
Fully Closed
Fully
Open
EP2 VPA2 VCP2 EP1 VPA1 VCP1
Output Voltage
Accelerator Position Sensor
Output Voltage Characteristic
VPA2
VPA1
Fully Closed Fully Open
Accelerator Pedal Position
Q000880E
1– 72
Operation Section
(3) Intake Air Temperature Sensor
• The intake air temperature sensor detects the temperature of the intake air after it has passed the turbocharger. The sensor portion that detects the temperature contains a thermistor. The thermistor, which has
an electrical resistance that changes with temperature, is used to detect the intake air temperature.
Thermistor
Resistance
Resistance - Temperature
Characteristic
Temperature
Q000881E
(4) Mass Airflow Meter (with Built-In Intake Air Temperature Sensor)
• The mass air flow meter is installed behind the air cleaner and detects the intake air flow (mass flow). This
sensor is a hot-wire type. Since the electrical resistance of the hot wire varies with the temperature, this
characteristic is utilized to measure the intake air quantity. The mass airflow meter also has a built-in intake air temperature sensor (thermistor type) and detects the intake air temperature (atmospheric temperature).
Intake Air
Temperature
Sensor
+B
E2G
VG THAF
Resistance
Intake Air Temperature
Temperature
Sensor Resistance
Characteristic
E2
Hot Wire
Temperature C ( F)
Q000882E
(5) Coolant Temperature Sensor
• The coolant temperature sensor is installed on the cylinder block and detects the coolant temperature.
This sensor is a thermistor type.
Coolant Temperature Water Temperature
Sensor Resistance
Characteristic
+5V
Thermistor
VTHW
A-GND
Resistance Value
ECU
Coolant Temperature
Q000883E
Operation Section
1– 73
(6) Fuel Temperature Sensor
• This is a thermistor type sensor that detects the fuel temperature. In the HP2, HP3, and HP4 systems,
this sensor is installed on the supply pump unit, but in the HP0 system, it is installed on a leak pipe from
an injector.
Resistance - Temperature
Characteristic
Resistance Value
Thermistor
Temperature
Q000848E
(7) Intake Air Temperature Sensor and Atmospheric Pressure Sensor
• This sensor is a semiconductor type sensor. It measures pressure utilizing the piezoelectric effect that
when the pressure on the silicon element in the sensor changes, its electrical resistance changes. In addition, the air pressure on this sensor is switched between the pressure within the intake manifold and the
atmospheric pressure, so both the intake air pressure and the atmospheric pressure are detected with
one sensor. The switching between intake air pressure and atmospheric pressure is handled by the VSV
(vacuum switching valve). When any one of the conditions below is established, the VSV is switched ON
for 150 msec. by command of the engine ECU to detect the atmospheric pressure. When none of the
conditions below is established, the VSV is switched OFF to detect the intake air pressure.
Atmospheric Pressure Measurement Conditions
9 Engine speed = 0 rpm
9 Starter ON
9 Stable idling state
PIM Output Voltage PIM
E2
Output Voltage
VC
Pressure
Characteristic
Absolute Pressure
Q000885E
1– 74
Operation Section
7. CONTROL SYSTEM
7.1 Fuel Injection Control
(1) General Description
• This system effects more appropriate control of the fuel injection quantity and injection timing than the
mechanical governor or timer used in the conventional injection pump. The engine ECU performs the necessary calculations based on the signals that are received from the sensors located on the engine and
the vehicle. Then, the ECU controls the timing and duration of the current that is applied to the injectors
in order to obtain optimal injection timing and injection quantity.
(2) Various Types of Fuel Injection Controls
Control
Fuel Injection Quantity Control
Functions
This control replaces the function of the governor in the conventional
injection pump. It achieves optimal injection quantity by effecting control in
accordance with the engine speed and accelerator opening signals.
Fuel Injection Timing Control
This control replaces the function of the timer in the conventional injection
pump. It achieves optimal injection timing by effecting control in accordance with the engine speed and the injection quantity.
Fuel Injection Rate Control
This function controls the ratio of the fuel quantity that is injected from the
(Pilot Injection Control)
orifice of the injector within a given unit of time.
Fuel Injection Pressure Control
This control uses the rail pressure sensor to measure the fuel pressure,
and it feeds this data to the engine ECU in order to control the pump discharge quantity.
Operation Section
1– 75
(3) Fuel Injection Quantity Control
General Description
• This control determines the fuel injection quantity by adding coolant temperature, fuel temperature, intake
air temperature, and intake air pressure corrections to the basic injection quantity. The engine ECU calculates the basic injection quantity based on the engine operating conditions and driving conditions.
Injection Quantity Calculation Method
• The calculation consists of a comparison of the following two values: 1. The basic injection quantity that
is obtained from the governor pattern, which is calculated from the accelerator position and the engine
speed. 2. The injection quantity obtained by adding various types of corrections to the maximum injection
quantity obtained from the engine speed. The lesser of the two injection quantities is used as the basis
for the final injection quantity.
Injection
Quantity
Accelerator Opening
Engine Speed
Accelerator Opening
Basic Injection Quantity
Engine Speed
Low
Quantity
Side Selected
Corrected
Final Injection
Quantity
Injector Actuation
Period Calculation
Maximum Injection Quantity
Individual Cylinder
Correction Quantity
Speed Correction
Injection
Quantity
Injection Pressure Correction
Intake Air Pressure Correction
Engine Speed
Intake Air Temperature Correction
Atmospheric Pressure Correction
Ambient Temperature Correction
Cold Engine Maximum Injection Quantity Correction
Q000887E
Operation Section
Set Injection Quantities
• Basic Injection Quantity
This quantity is determined by the engine speed and the accelerator opening. With the engine speed constant, if the accelerator opening increases, the injection quantity increases; with the accelerator opening
Basic Injection Quantity
constant, if the engine speed rises, the injection quantity decreases.
Accelerator Opening
Engine Speed
Q000888E
• Starting Injection Quantity
This is determined based on the basic injection quantity for when the engine starts up and the added corrections for the starter S/W ON time, the engine speed, and the coolant temperature. If the coolant temperature is low, the injection quantity is increased. When the engine has completely started up, this mode
is cancelled.
Injection Quantity
Coolant Temperature
High
Low
Starting
Base Injection
Quantity
STA ON Time
STA ON
Starting
Q000889E
• Injection Quantity for Maximum Speed Setting
Determined by the engine speed. The injection quantity is restricted to prevent an excessive rise in engine
speed (overrun).
Injection Quantity
1– 76
Injection Quantity
for Maximum Speed Setting
Engine Speed
Q000890E
Operation Section
1– 77
• Maximum Injection Quantity
This is determined based on the basic maximum injection quantity determined by the engine speed, and
the added corrections for coolant temperature, fuel temperature, intake air temperature, atmospheric
temperature, intake air pressure, atmospheric pressure, and full Q adjustment resistance (only for the 1st
Basic Maximum
Injection Quantity
generation HP0 system), etc.
Engine Speed
QB0717E
Corrections
• Cold Engine Maximum Injection Quantity Correction
When the coolant temperature is low, whether during start-up or during normal operation, this correction
Injection Quantity
increases the injection quantity.
Engine Speed
Q000891E
• Intake Air Pressure Correction
When the intake air pressure is low, the maximum injection quantity is restricted in order to reduce the
Injection Quantity
emission of black smoke.
Intake Air Pressure
Correction Quantity
Engine Speed
Q000892E
Operation Section
• Atmospheric Pressure Correction
The maximum injection quantity is increased and decreased according to the atmospheric pressure.
Injection Quantity
When the atmospheric pressure is high, the maximum injection quantity is increased.
Atmospheric Pressure
Correction Quantity
Engine Speed
Q000893E
• Injection Quantity Delay Correction for Acceleration
During acceleration, if there is a large change in the accelerator pedal opening, the injection quantity increase is delayed in order to prevent black smoke emissions.
Change in Accelerator
Pedal Position
Injection Quantity
Injection Quantity
After Correction
Delay
Time
Q000487E
• Full Q Adjustment Resistance (Only for 1st Generation HP0 Systems)
The full Q resistance is for correcting the injection quantity for a full load. The maximum injection quantity
is increased or decreased by the car manufacturer to match to standards. There are 15 types of full Q
adjustment resistance. The appropriate one is selected and used.
ECU
+5V
VLQC
A-GND
Quantity Adjustment
Correction Injection Quantity
1– 78
Quantity Adjustment
Resistor Correction Voltage
Operation Section
1– 79
(4) Fuel Injection Rate Control
• Although the injection rate increases with the adoption of high-pressure fuel injection, the ignition lag,
which is the delay from the start of injection to the beginning of combustion, cannot be shortened to less
than a certain period of time. Therefore, the quantity of fuel injected until ignition takes place increases
(the initial injection rate is too high), resulting in explosive combustion simultaneous with ignition, and an
increase in NOx and sound. To counteract this situation, pilot injection is provided to keep the initial injection at the minimum requirement rate, to dampen the primary explosive combustion, and to reduce
NOx and noise.
[Ordinary Injection]
[Pilot Injection]
Injection Rate
Small First-Stage
Combustion
Large First-Stage
Combustion
Heat Release Rate
-20
TDC
Crankshaft Angle (deg)
20
40
-20
TDC
20
40
Crankshaft Angle (deg)
Q000895E
1– 80
Operation Section
(5) Fuel Injection Timing Control
• The fuel injection timing is controlled by the timing of the current applied to the injectors. After the main
injection period is decided, the pilot injection and other injection timing is determined.
Main Injection Timing
9 The basic injection timing is calculated from the engine speed (engine speed pulse) and the final injection quantity, to which various types of corrections are added in order to determine the optimal main
injection timing.
Pilot Injection Timing (Pilot Interval)
9 Pilot injection timing is controlled by adding a pilot interval value to the main injection. The pilot interval
is calculated based on the final injection quantity, engine speed, coolant temperature, atmospheric
temperature, and atmospheric pressure (map correction). The pilot interval at the time the engine is
Pilot Interval
Basic Injection
Timing
Pilot Interval
Basic Injection Timing
started is calculated from the coolant temperature and engine speed.
Engine Speed
Engine Speed
1. Outline of Injection Timing Control Timing
0
Engine Speed
Pulse
NE
Injector Solenoid Valve
Control Pulse
INJ
Nozzle Needle
Lift
lift
Actual Top Dead Center
1
Pilot Injection
Main Injection
Pilot Injection Timing
Main Injection Timing
Pilot Interval
2. Injection Timing Calculation Method
Engine Speed
Injection Quantity
Main
Injection Timing
Basic Injection
Timing
Correction
Pilot
Injection Timing
Battery Voltage Correction
Intake Air Pressure Correction
Intake Air Temperature Correction
Atmospheric Pressure Correction
Coolant Temperature Correction
Q000896E
Operation Section
1– 81
Split Injection
9 The purpose of split injection is to improve the startability of a cold engine. Before the conventional
main injection takes place, this function injects two or more extremely small injections of fuel.
Main Injection
Main Injection
Pilot Injection
This is the same as conventional
fuel injection.
Pilot Injection
Before the main injection, a small
quantity of fuel is injected.
Pilot Injection
Pre-Injection
Multi-Injection
If the temperature is low when the engine
starts, a small quantity of fuel is injected
divided over multiple injections before the
main injection.
Q000897E
Multi-Injection Control (Only for Some Models)
9 Multi-injection control is when small injections (up to four times) are carried out before and after the
main injection in accordance with the state of the main injection and engine operation. This interval (the
time A-D in the diagram below) is based on the final injection quantity, engine speed, coolant temperature, and atmospheric pressure (map correction). The interval during start-up is based on the coolant
temperature and engine speed.
TDC
TDC (G) Pulse
A
B
C
D
Injection Rate
Q000898E
1– 82
Operation Section
(6) Fuel Injection Pressure Control
• The engine ECU calculates the fuel injection pressure, which is determined by the final injection quantity
and the engine speed. The calculation is based on the coolant temperature and engine speed during
start-up.
Rail Pressure
Final Injection Quantity
Engine Speed
Q000899E
Operation Section
1– 83
(7) Other Injection Quantity Control
Idle Speed Control (ISC) System
• The idle speed control system controls the idle speed by regulating the injection quantity in order to match
the actual speed to the target speed calculated by the computer. The ISC can be automatic ISC or manual
ISC.
Automatic ISC
9 With automatic ISC, the engine ECU sets the target speed. The target engine speed varies with the
type of transmission (automatic or manual), whether the air conditioner is ON or OFF, the shift position,
and the coolant temperature.
Idle Speed Control Conditions
Conditions When Control Starts
Conditions Affecting Control
· Idle Switch
· Water Temperature
· Accelerator Opening
· Air Conditioning Load
· Vehicle Speed
· Shift Position
Engine ECU
Target Engine Speed Calculation
Comparison
Actual Engine Speed
Fuel injection Quantity Correction
Fuel Injection Quantity Instruction
Actuators
Q000900E
1– 84
Operation Section
Manual ISC
9 The idle engine speed is controlled by the setting on the idle setting button at the driver's seat.
ECU
A-VCC
Target Engine Speed
+5V
V-IMC
A-GND
IMC Volume Terminal Voltage
Q000901E
Idle Vibration Reduction Control
9 This control reduces engine vibration during idle. To achieve smooth engine operation, it compares the
angle speeds (times) of the cylinders and regulates injection quantity for each individual cylinder in the
event of a large difference.
#1
#3
t1
#4
t3
(Make the
t4
t for all the cylinders equal.)
Angular Speed
#1
#3
#4
#2
Crankshaft Angle
#1
Correction
#3
#4
#2
Crankshaft Angle
Q000902E
Operation Section
1– 85
7.2 E-EGR System (Electric-Exhaust Gas Recirculation)
(1) General Description
• The E-EGR system is an electronically controlled EGR system. The EGR system recirculates a portion
of the exhaust gases into the intake manifold in order to lower the combustion chamber temperature and
reduce NOx emissions. However, operation of the EGR system may reduce engine power output and affect drivability. For this reason, in the E-EGR system, the engine ECU controls the EGR to achieve an
optimal EGR amount.
Operation Conditions Example
9 This operates in the operation region fulfilling the starting conditions below (one example).
Injection Quantity
· Engine Operating Conditions
· · · · · Except during engine warm-up and startup,
does not overheat, etc.
· EGR Operating Range
· · · · · · · · For Engine Medium Load
Engine Speed
Q000501E
(2) Operation
• After the vacuum pump generates a vacuum, the E-VRV (electric-vacuum regulation valve) regulates the
vacuum and directs it to the diaphragm chamber of the EGR valve. In response to this vacuum, the diaphragm pushes the spring downward, which determines the opening of the EGR valve and controls the
EGR volume.
• The EGR cooler, which is provided in the EGR passage between the cylinder head and the intake passage, cools the EGR in order to increase the EGR volume.
• The EGR cutoff VSV, which opens the diaphragm chamber to the atmosphere when the EGR valve is
closed, helps to improve response.
Diaphragm
Vacuum Pump
Vacuum Damper
EGR Valve
E-VRV
Spring
EGR Shut-Off VSV
Coolant
EGR Cooler
Engine
Control Unit
Exhaust
Manifold
Engine Speed
Accelerator Opening
Intake Air Pressure And
Atmospheric Pressure
Coolant Temperature
Intake Air
Relationship Between Vacuum and EGR Valve Opening
Low
Small
Vacuum
High
EGR Valve Opening
Large
Q000903E
1– 86
Operation Section
To Increase the EGR Quantity
9 The E-VRV duty ratio is controlled*. In the stable condition shown in the bottom center diagram, an increase in the current that is applied to the coil causes the attraction force FM in the coil to increase.
When this force becomes greater than the vacuum force FV that acts on the diaphragm, the moving
core moves downward. Along with this movement, the port from the vacuum pump to the upper chamber of the diaphragm opens. Consequently, the output vacuum increases, which causes the EGR valve
to open and the EGR volume to increase. Meanwhile, because "increased output vacuum equals increased FV", the moving core moves upward with the increase in FV. When FM and FV are equal, the
port closes and the forces stabilize. Because the vacuum circuit of the EGR is a closed loop, it maintains the vacuum in a stabilized state, provided there are no changes in the amperage.
* : The engine ECU outputs sawtooth wave signals with a constant frequency. The value of the current
is the effective (average) value of these signals. For details, see the explanation of the HP3 supply
pump and SCV.
To Decrease the EGR Volume
9 A decrease in the current that is applied to the coil causes FV to become greater than FM. As a result,
the diaphragm moves upward. The moving core also moves upward in conjunction with the movement
of the diaphragm, causing the valve that seals the upper and lower diaphragm chambers to open. Consequently, the atmospheric pressure in the lower chamber enters the upper chamber, thus reducing
the output vacuum. This causes the EGR valve to close and the EGR volume to decrease. Because
"decreased output vacuum equals decreased FV", the moving core moves downward with the decrease in FV. When FM and FV are equal, the port closes and the forces stabilize.
From Vacuum Pump
To EGR Valve
FV
Valve
Spring
Moving Core
Diaphragm
FM
Coil
Stator Core
FM > FV
EGR Quantity Increased
Atmosphere
FM < FV
EGR Quantity Decreased
Q000904E
Operation Section
1– 87
7.3 Electronically Controlled Throttle (Not Made By DENSO)
(1) General Description
• The electronically controlled throttle is located upstream of the EGR valve in the intake manifold. It controls the throttle valve at an optimal angle to regulate the EGR gas and reduce noise and harmful exhaust
gases.
(2) Operation
• Signals from the engine ECU actuate the stepping motor, which regulates the throttle valve opening.
EGR Control
• To further increase the EGR volume when the EGR valve is fully open, the vacuum in the intake manifold
can be increased by reducing the throttle valve opening, which restricts the flow of the intake air.
Noise and Exhaust Gas Reduction
• When the engine is being started, the throttle valve opens fully to reduce the emissions of white and black
smoke.
• When the engine is being stopped, the throttle valve closes fully to reduce vibration and noise.
• During normal driving, the throttle valve opening is controlled in accordance with the engine conditions,
coolant temperature, and atmospheric pressure.
Stepping Motor
Throttle Valve
Q000905E
1– 88
Operation Section
7.4 Exhaust Gas Control System
(1) General Description
• The exhaust gas control system is provided to improve warm-up and heater performance. This system
actuates the exhaust gas control valve VSV, which is attached to the exhaust manifold. It increases the
exhaust pressure to increase the exhaust temperature and engine load, in order to improve warm-up and
heater performance.
Vacuum Pump
Exhaust Gas
Control Valve
Air Cleaner
VSV
Turbo Pressure
Sensor
Coolant Temperature
Sensor
Exhaust Gas
Control Valve
EGR Valve Position
Sensor
ECU
Warm-Up Switch
Mass Airflow Meter
Cylinder
Recognition Sensor
(TDC (G) Sensor)
Accelerator
Position Sensor
Atmospheric
Pressure Sensor
Q000906E
(2) Operation
• The exhaust gas control system operates when the warm-up switch is ON, and all the conditions listed
below have been met.
Operation Conditions
9 The EGR is operating.
9 The coolant temperature is below 70°C.
9 The ambient temperature is below 5°C.
9 A minimum of 10 seconds have elapsed after starting the engine.
9 The engine speed and fuel injection quantity are in the state shown in the graph below.
[Exhaust Gas Control System Operating Range]
Operating Range
Extremely Low Torque
or Engine Speed Range
Injection Quantity
WARM UP
Engine Speed
Q000907E
Operation Section
1– 89
7.5 DPF System (Diesel Particulate Filter)
(1) General Description
• This system reduces emissions of PM (particulate matter). In order to collect PM, a DPF cleaner with builtin catalytic filter is mounted on the center pipe. The collected PM is handled with combustion processing
during operation.
(2) System Configuration
Rail
Intercooler
G2 Injector
Intake Air
Pressure Sensor
EGR Cooler
VNT Actuator
EGR Valve
Equilibrium
Actuator
Supply Pump
DPF (with
Oxidation Catalyst)
Exhaust Gas
Temperature Sensor
ECU & EDU
Differential Pressure Sensor
Exhaust Gas Temperature Sensor
Q000908E
1– 90
Operation Section
(3) Various Sensors
Exhaust Gas Temperature Sensor
• The exhaust gas temperature sensor is installed to the front and rear of the DPF to detect the temperature
in these positions. The engine ECU controls the exhaust temperature for PM combustion based on the
signals from this sensor. The sensor element is a thermistor.
Resistance Value (
)
Thermistor Element
Cover
Exhaust Gas Temperature (
)
Q000909E
Differential Pressure Sensor
• The differential pressure sensor detects the difference in pressure at the front and rear of the DPF, and
outputs a signal to the engine ECU. The sensor portion is a semiconductor type pressure sensor that utilizes the piezoelectric effect through a silicon element, and amplifies and outputs the voltage with its IC
circuit. When PM is collected and accumulated in the DPF, the filter clogs and the difference in pressure
at the front and rear of the DPF increases. Therefore, based on the signals from this sensor, the engine
VP
VC
(V)
GND
VP Output Voltage
ECU judges whether or not to subject PM to combustion processing.
Pressure (kPa)
Q000910E
Operation Section
1– 91
(4) Operation
• By optimizing the injection pattern and controlling the exhaust gas temperature based on the exhaust gas
temperature and the difference in pressure at the front and rear of the DPF, PM is collected, oxidized, and
self-combusted. When the exhaust temperature is low, adding after-injection after the main injection raises the exhaust gas temperature to approximately 250?C and promotes oxidation of the PM. When the
PM is collected and accumulated, the post-injection is added and HC is added to the catalyst to raise the
catalyst temperature to 600?C, which is the self-combustion temperature for PM. This combusts the accumulated PM in a short time. The engine ECU controls the A, B, and C times and the injection times.
TDC
B
A
C
After-Injection
Post-Injection
Q000506E
1– 92
Operation Section
(5) HINO vehicles (HINO designation: Diesel Particulate active Reduction (DPR) system)
• The following is an explanation of the DPR system equipped in HINO trucks. The DPR system has an
exhaust gas purification device switch and indicator light located near the driver's seat.
Exhaust Gas Purification Device Switch
Q002667E
Operation Section
1– 93
• Automatic and manual DPR system operation are explained below.
9 PM accumulated in the DPR is automatically regenerated at the following rates: 1) once every approximately 200 kilometers when driving on general roads, or 2) once every approximately 500 kilometers
when driving on highways.
9 Depending on driving conditions, there are cases when regeneration is not performed automatically.
When soot is not being regenerated automatically, the following two indicator lights blink: 1) the light
built into the switch for the exhaust gas purification device, and 2) the light for the exhaust gas purification device located inside the meter panel. These indicator lights are a notification to press the exhaust
gas purification device switch to begin manual soot regeneration.
Exhaust Gas Purification
Device Indicator Light
Malfunction Indicator Lamp (MIL)
Engine
ECU
Differential Pressure Sensorwitch
Exhaust Gas Purification Device Switch
Exhaust Gas Recirculation (EGR) Valve
Magnetic Valve
Exhaust
Control Valve
Exhaust Gas Temperature Sensor
Exhaust Gas Temperature Sensor
Injectors
< Engine >
< DPR Cleaner Unit >
Q002668E
• Under regenerative operation, Hydro-Carbon (HC) is added to the catalyst by the post-injection. As a result, the catalyst temperature increases up to 600 °C, the self-combustion temperature of the Particulate
Matter (PM). At 600 °C, the PM accumulated in the catalyst can be quickly regenerated.
• The differential pressure sensor detects DPR filter clogging. If the DPR filter becomes clogged, regeneration initiates automatically. The exhaust gas temperature sensor monitors exhaust gas temperature during regeneration. If the exhaust gas temperature becomes abnormally high, regeneration is forcibly
suspended.
1– 94
Operation Section
7.6 DPNR SYSTEM (DIESEL PARTICULATE NOx REDUCTION)
(1) General Description
• This system reduces the emissions of PM (particulate matter) and NOx. The DPNR catalyst mounted in
the center pipe collects and regenerates PM and reduces NOx all at the same time. The collected PM is
handled with combustion processing during operation.
(2) System Configuration
Exhaust Gas Cleaning
Device Switch
Supply Pump
Exhaust Gas Cleaning
Device Display Lamp
Intake Restriction Valve
Injector
Engine ECU
Exhaust
Retarder VSV
DPNR Catalyst
Oxidation Catalyst
A/F Sensor
Oxidation Catalyst
Before EGR Cooler
Fuel Addition Valve
A/F Sensor
Exhaust Retarder
NSR Differential Pressure Sensor
Exhaust Gas Temperature Sensor
Q000911E
Operation Section
1– 95
8. DIAGNOSIS
8.1 Outline Of The Diagnostic Function
z The diagnostic function enables a system to self-diagnose its own malfunctions. If abnormal conditions occur in the sensors or actuators used in the control systems, the respective systems convert the malfunction
signals into codes and transmit them to the engine ECU. The engine ECU records the transmitted malfunction code into memory. Recorded codes are output at the diagnostics connector on the vehicle. To inform
the driver of the malfunction, the engine ECU causes the MIL (Malfunction Indicator Light) in the meter to
illuminate. Accurate troubleshooting can be performed by way of the DTCs (Diagnostic Trouble Codes) that
are output at the diagnostic connector. For details on actual diagnosis codes, see the vehicle manual. It is
necessary to put the vehicle into the state below before starting inspection.
(1) Pre-Inspection Preparation
• Position the shift lever in "N" or "P".
• Turn OFF the air conditioner.
• Verify that the throttle valve is fully closed.
8.2 Diagnosis Inspection Using DST-1
z The DST-1 can be used in both normal and check modes. Compared to the normal mode, the check mode
has a higher sensitivity to detect malfunctions.
z The check mode inspection is performed when normal codes are output in the normal mode, despite the
fact that there may be malfunctions in the sensor signal systems.
(1) Reading DTCs
1) DST-1 Connection: Connect the DST-1 to the DLC3
terminal.
DLC3
16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1
Q000914
1– 96
Operation Section
2) Reading DTCs: Operate in accordance with the instructions shown on the screen to display the "DTC
Diagnostic Trouble Codes (DTC)
1.
check" screen. Select either the normal or check
···
mode and read the DTC.
[ REFERENCE ]
If no DTC appears on the screen, there may be a
failure in the engine ECU.
Execute: Execute
Q000915E
3) Checking the Freeze Frame Data: If the symptom that outputs a DTC cannot be duplicated, check the freeze frame
data.
4) Erasing DTCs from memory: Operate in accordance
Diagnostic Trouble Code (ECD Erasure)
with the instructions shown on the screen to display
This will erase the DTC and freeze frame data.
the "DTC check" screen. Select "Erase DTCs" to
Erase OK?
erase the DTCs.
[ REFERENCE ]
If it is not possible to erase the DTC, turn the ignition switch OFF, and repeat the process.
No : - OK : +
Q000916E
5) Wiring Harness and Connector Open Circuit Check
[ REFERENCE ]
If the DTC output during a diagnostic inspection (in
the check mode) has identified the system with a
malfunction, use the method indicated below to
narrow down the area of the malfunction.
• Erasing DTCs from memory: After reading the DTCs in check mode, erase the DTCs from memory.
• Starting the Engine: Select the check mode and start the engine.
• Malfunctioning system check 1: While the engine is running at idle, shake the wiring harness and connectors of the system that output the malfunction during the diagnosis (check mode) inspection.
• Malfunctioning system check 2: If the MIL (Malfunction Indicator Light) illuminates when the wiring harness and connectors are shaken, there is a poor contact in the wiring harness or connectors in that area.
8.3 Diagnosis Inspection Using The MIL (Malfunction Indicator Light)
z Before reading a DTC, turn the ignition switch ON to make sure the MIL (Malfunction Indicator Light) illuminates.
z Inspections in the check mode cannot be performed.
Operation Section
1– 97
(1) Reading DTCs
Short circuiting the connector
• Using the STT, short circuit between DLC1 terminals 8 (TE1) and 3 (E1) or between DLC3 terminals 13
(TC) and 4 (CG).
DLC1
DLC3
E1
TC
1 2
3
4
5 6
16 15 14 13 12 11 10 9
18
19
TE1
7 8
9
12 13 14
15
10 11
20
16 17
21
8 7 6 5 4 3 2 1
22 23
CG
Q000917E
< ATTENTION >
Never connect the wrong terminals of the connectors as this will lead to a malfunction.
Reading DTCs 1
• Turn the ignition switch ON and count the number of times the MIL (Malfunction Indicator Light) blinks
· Normal Operation
0.26sec
0.26sec
Repeat
ON
OFF
Malfunction
Indicator Light
0.26sec
Jump Terminals TE1 and TC
· Malfunction (Codes "12" and "23" are output.)
0.52sec 1.5sec
2.5sec
1.5sec
4.5sec
4.5sec
Repeat Thereafter
ON
OFF
0.52sec
0.52sec
Jump Terminals TE1 and TC
Q000918E
[ REFERENCE ]
If the MIL (Malfunction Indicator Light) does not output a code (the light does not blink), there may be an
open circuit in the TC terminal system or a failure in the engine ECU.
If the malfunction indicator light is constantly ON, there may be a short (pinching) in the wiring harness or
a failure in the engine ECU.
If meaningless DTCs are output, there may be a malfunction in the engine ECU.
If the MIL (Malfunction Indicator Light) illuminates without outputting a DTC while the engine operates at a
minimum speed of 1000rpm, turn the ignition switch OFF once; then resume the inspection.
1– 98
Operation Section
Reading DTCs 2
• If an abnormal DTC has been output, check it against the DTC list.
Erasing DTCs from memory
• Remove the ECD fuse (15A); after 15 seconds have elapsed, re-install the fuse.
Engine Compartment Relay Block
ECD Fuse (15A)
Q000919E
< ATTENTION >
After completing the inspection of the ECD system, erase the DTC memory, and make sure the normal code is output.
8.4 Throttle Body Function Inspection
< ATTENTION >
• Be sure to inspect the function of the throttle body after it has been disassembled and reassembled, or after any of its components have been removed and reinstalled.
• Verifying Throttle Motor: Verify that the motor generates an operating sound when the ignition
switch is turned ON. Also, verify that there is no interference sound.
(1) Erasing DTCs
1) Connect the DST-1 to the DLC3 connector.
DLC3
16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1
Q000914
Operation Section
1– 99
2) Operate in accordance with the instructions shown on
Diagnostic Trouble Code (ECD Erasure)
the screen to display the "DTC check" screen. Select
This will erase the DTC and freeze frame data.
"Erase DTCs" to erase the DTCs.
Erase OK?
No : - OK : +
Q000916E
(2) Inspection
• Start the engine and make sure the MIL (Malfunction Indicator Light) does not illuminate and the engine
speed is within standards when the air conditioner is turned ON and OFF after the engine has warmed up.
< ATTENTION >
Make sure no electrical load is applied.
(3) Final Inspection
• After inspecting the throttle body function, drive test the vehicle to confirm that operation is normal.
1– 100
Operation Section
9. END OF VOLUME MATERIALS
9.1 Particulate Matter (PM)
z At high concentration levels, this substance is known to affect the respiratory system. It consists of soluble
organic matter such as unburned oil, unburned diesel fuel, and other "soluble organic matter" in the exhaust
gases, and insoluble organic matter such as soot (black smoke) and sulfuric acid gas.
9.2 Common Rail Type Fuel Injection System Development History And
The World’s Manufacturers
z The conventional injection pump faced certain issues such as injection pressure that depended on engine
speed, and limits on the maximum fuel pressure. Other types of injection control such as pilot injection also
faced some difficulties. Addressing these issues in a revolutionary manner, DENSO led the world by introducing a commercial application of the common rail fuel injection system.
z Two types of common rail fuel injection systems are in use today. One is the common rail system that pressurizes the fuel and injects it directly into the cylinders. DENSO was the first in the world to introduce a commercial application of this system. This system, which is undergoing further development, has been adopted
in passenger car applications. Other companies, such as R. Bosch, Siemens, and Delphi also offer their
commercial versions of this system today. The other system is the Hydraulic Electric Unit Injection (HEUI)
system, which was developed by Caterpillar in the United States. This system uses pressurized engine oil
to pressurize the fuel by actuating the piston of the nozzle (injector) through which the pressurized fuel is
injected.
Operation Section
1– 101
9.3 Higher Injection Pressure, Optimized Injection Rates, Higher Injection
Timing Control Precision, Higher Injection Quantity Control Precision
(1) Higher Injection Pressure
• The fuel that is injected from the nozzle turns into finer particles as the fuel injection pressure increases.
This improves combustion and reduces the amount of smoke contained in the exhaust gases. Initially,
the maximum injection pressure of the in-line pump (A type) and the distributor pump (VE type) was 60
MPa. Due to advancement in high-pressure applications, there are some recently developed fuel injection
systems that inject fuel at a pressure of 100 MPa or higher. The second-generation common rail system
injects fuel at an extremely high pressure of 180 MPa.
A Type Pump
Mechanical Pump
Distributor Type Pump
NB Type Pump
1 MPa is
approximately 10.2kgf/cm2
ECD V3 Pump
ECD V Series
(1st Generation)
ECD V4 Pump
120
HP0Pump
120
145
HP2Pump
Common Rail Series
(2nd Generation) HP3,4Pump
185
50
100
150
200
Injection Pressure (MPa)
Q000920E
(2) Optimized Injection Rates
• The injection rate is the ratio of the changes in the fuel quantity that is injected successively from the nozzle within a given unit of time.
High Injection Rate
Injection Quantity
Injection Rate
t
Q000921E
1– 102
Operation Section
• As the injection pressure increases, the injection rate increases accordingly. The increase in injection rate leads to
an increase in the volume of the air-fuel mixture that is created between the start of injection until ignition (the ignition
lag period). Because this mixture is subsequently combusted at once, it creates noise (diesel knock) and NOx. For
this reason, it is necessary to appropriately control the injection rate by maintaining a low injection rate at the beginning of injection and supplying a sufficient quantity after the ignition. To meet this need, two-spring nozzles have been
adopted and a pilot injection system has recently been developed.
Injection Quantity
Common Rail System
Injection Rate Control
Injection Quantity
2-Spring Nozzle
Injection Rate
Pilot Injection
Q000922E
(3) Higher Injection Timing Control Precision
• Reducing exhaust gas emissions and fuel consumption and optimizing the injection timing are important.
It is extremely difficult to achieve the desired exhaust emission reduction levels through methods that adjust the injection timing according to speed (or centrifugal force), such as the conventional mechanical
timer. For this reason, electronically controlled systems have been adopted to freely and precisely control
the injection timing in accordance with the engine characteristics.
ti on
Q ua
ntity
Engine Speed
Injec
t i on
Advance
Angle
Injec
Mechanical Timer
Advance
Angle
Electronic Control Type
Q ua
ntity
Engine Speed
Q000923E
(4) Higher Injection Quantity Control Precision
• Power output adjustment in a diesel engine is accomplished by regulating the fuel injection quantity. Poor
injection quantity control precision leads to increased exhaust gas emissions, noise, and poor fuel economy. For this reason, electronically controlled systems have been developed to ensure high precision injection quantity control.
Operation Section
1– 103
9.4 Image Of Combustion Chamber Interior
z With conventional injection methods, because an excessive quantity of fuel was injected in the initial period,
the explosion pressure rose excessively, leading to the generation of noise such as engine knocking
sounds. To improve this condition through pilot injection, initially only the necessary and adequate quantity
of fuel is injected. At the same time, the combustion chamber temperature is raised, and main injection combustion is assisted while working to prevent noise and vibration.
Conventional Injection
Pilot Injection
Q000924E
2– 104
Repair Section
1. DIESEL ENGINE MALFUNCTIONS AND DIAGNOSTIC METHODS (BASIC KNOWLEDGE)
1.1 Combustion State and Malfunction Cause
z Depending on the state of combustion in a diesel engine, diesel knock as well as the color of the exhaust
gas may change. Subsequently, the cause of engine malfunctions can be ascertained from changes in diesel knock and exhaust gas color.
Knocking
Sound
Black
Smoke
White
Smoke
Q002310E
(1) Diesel Knock
• When fuel mixed with air during the ignition lag period (from the time injection begins until the fuel is ignited) reaches
ignition temperature, the mixture is combusted in one burst. The pressure in the combustion chamber at this time rises
as the quantity of the air-fuel mixture increases. If a large amount of air-fuel mixture is created during the ignition lag
period, the pressure in the combustion chamber will rise rapidly. The pressure waves resulting from fuel ignition vibrate the cylinder walls and engine components, which generates noise. The generated noise is called "knocking".
To some extent, knocking is unavoidable in engines that use a self-ignition system.
Cylinder Internal Pressure
Pressure Increase
Ignition
Start of
Injection
T.D.C. Crankshaft Angle
Q002311E
Cause of Diesel Knocking
1
Early Injection Timing
2
Cold Engine
3
Intake air temperature is low.
4
Poor Engine Compression
5
Poor Fuel Combustibility
A large quantity of air-fuel mixture is created prior to ignition, or
the cetane value is high.
Ignition occurs late without an increase in temperature.
Ignition occurs late (low cetane value.)
Repair Section
2– 105
(2) White Smoke
White smoke: Uncombusted fuel that has been vaporized and then discharged.
• White smoke is generated when combustion occurs at a relatively low temperature, resulting in the exhaust of uncombusted fuel and oil particles. White smoke is most likely to be generated when combustion chamber temperature
is low.
Source of White Smoke
1
Late Injection Timing
2
Cold Engine
3
Poor Fuel Combustibility
4
Rise and Fall of Oil Pressure
Fuel is injected when the piston is in the down stroke.
Ignition occurs late and combustion is prolonged.
Oil undergoes partial thermal breakdown.
(3) Black Smoke
Black smoke: Fuel that has been baked into soot and discharged.
• Black smoke is often referred to as just "smoke". Black smoke is generated when the injected fuel is poor in oxygen.
As the fuel is exposed to high temperatures, thermal breakdown occurs, leaving carbon behind. Black smoke occurs
when the injected fuel quantity is too large, or when the air-fuel mixture is rich due to an insufficient quantity of air.
Source of Black Smoke
1
Large Fuel Injection Quantity
Air-fuel mixture becomes rich.
2
Low Intake Air Quantity
Air quantity is insufficient due to air filter clogging.
3
Poor Fuel Atomization
The ratio of fuel to air worsens.
4
Retarded Fuel Injection Timing
Air-fuel mixing time is insufficient.
1.2 Troubleshooting
Troubleshooting cautions
z Always observe the following attention points to avoid decreased engine performance and fuel injector malfunctions.
• Use the designated fuel.
• Do not allow water or foreign materials to enter the fuel tank.
• Periodically check and clean the filters.
• Do not unnecessarily disassemble sealed components.
Repair Section
2– 106
Troubleshooting notes
z The cause of malfunctions is not necessarily limited to the pump itself, but may also be related to the engine
and/or fuel systems. Further, the majority of malfunctions are the result of user error, and often can often
be resolved through simple checks and maintenance. Avoid any hasty removal of system components.
Basic Check Items
1
Engine Oil
7
Fuel Supply to the Pump
2
Coolant
8
Injector Injection Status
3
Fan Belt
9
Supply Pump Timing Mark
4
Air Cleaner
10
5
Battery and Terminals
11 Idle Speed Status
6
Fuel System Leaks
Check for Loose or Disconnected Connectors,
and Modifications
Repair Section
2– 107
2. DIAGNOSIS OVERVIEW
2.1 Diagnostic Work Flow
Diagnostic Procedures
1
Receive malfunctioning vehicle
2
Question the user to verify the nature of the
malfunction.
3
Does the malfunction reoccur?
Refer to "Actions for Non-Reoccurring Malfunctions."
4
Verify the malfunction symptom at the
actual vehicle.
5
Use the DST-2 to check for any DTCs.
Proceed with diagnostics while referencing
the DTC chart in the repair manual for the
appropriate vehicle.
6
7
Use the DST-2 "Data Monitor" function to
Proceed with diagnostics while referencing
perform checks while monitoring each
the repair manual for the appropriate vehi-
input and output signal.
cle.
Use the DST-2 active test function to oper-
Proceed with diagnostics while referencing
ate each output device with the ignition
the repair manual for the appropriate vehi-
switch in the ON position. Check for any
cle.
abnormalities in either the electrical circuits
or the output devices.
Repair Section
2– 108
8
Was the malfunction cleared?
Return to step 3.
2.2 Inquiries
z Use the Common Rail System (CRS) troubleshooting questionnaire to consult with the customer and adequately grasp the malfunction symptoms.
[ REFERENCE ]
Do not ask random questions. Rather, ask questions that will aid in narrowing down the possible malfunctioning system while making educated guesses based on the actual symptoms.
Questioning points
z Use the following questions as a basis to fully grasp the malfunction.
• What?: Malfunction symptoms
• When?: Date, time, frequency of occurrence
• Where?: Road conditions
• Under what conditions?: Driving conditions, engine operating conditions, weather
• How?: Impression of how the symptoms occurred.
CRS troubleshooting questionnaire
z When the vehicle is received at the service center, it is necessary to verify the "malfunction symptoms" and
the "generated malfunction data" with the customer. Consult with the customer using the CRS troubleshooting questionnaire. The troubleshooting questionnaire is necessary for the following reasons.
Reasons
• There are cases when the malfunction symptoms cannot be reproduced at the service center.
• The customer's complaint is not always limited to the malfunction.
• If the person performing repairs is not working from the correct malfunction symptoms, man-hours will be wasted.
• The questionnaire can aid the service center in diagnosing, repairing and verifying repair work.
Questioning Results
Inspection Results
Q002315E
Repair Section
2– 109
(1) Questionnaire
CRS Troubleshooting Questionnaire
Vehicle Model
Receiving Date
Service History
Frame No.
Date Registered
Registration No.
Occurrence Date
Odometer Reading
No / Yes (
times)
Main Area and Purpose of Use
Previous Vehicles Driven:
Other Customer Information
Indications from the Customer
MIL Illumination No / Yes (
System Conditions
Questioning
Results
Occurrence Speed
( ) km/hr
Shift Position
( ) Range
At Start-Up
Directly after Start-Up
Up to ( ) Minutes after Start
Up to ( ) Minutes into Driving
When Cold
When Warm
During Operation
Other (
)
)
Road Surface
Driving Conditions
During Take-Off
While Cruising
When Accelerating
When Decelerating
When Braking
When Turning
When Stopped
No Relationship
Other (
)
Other
Flat
Uphill
Downhill
Dry, Sealed road
Wet, Sealed Road
Unsealed Road or
Rough Road Surface
Snow-Covered or Icy Road
Potholes, Manholes, etc.
Other (
)
Accelerator
Opening
(
)%
Outside Air
Temperature
o
(
) C
Weather
(
)
Frequency of Occurrence
Normal
Only Once
Occasionally
( ) Times per Day
( ) Times per Week
( ) Times per Month
Additional Items
DTC Check
Illuminated
No
Yes
DTC Normal
Abnormal DTC (All Codes)
Fuel Pressure when Engine is Stopped
1 Minute after Turning Engine OFF
Malfunction Details: Time of occurrence, place and driving conditions during reoccurrence.
Inspection
Results
Reoccurrence
Conditions
Occurs Regularly
Occurs Occasionally
Continues to Appear
After One Occurrence
Does Not Reoccur
Q002316E
2– 110
Repair Section
2.3 Non-Reoccurring Malfunctions
z In cases where the malfunction does not reoccur, perform the actions below to determine the cause of the
malfunction.
Malfunction Symptom
Idle Speed,
Fully Dis-
Action
charged Battery
Engine will
not Start
Engine Stall,
Sputtering,
Poor Acceleration
Verify that there is no DTC stored in the memory.
No
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
No
No
Yes
No
No
Yes
Use the questionnaire as a basis to perform a reoccurrence
test in "Reoccurrence" mode. Use this data (engine ECU voltage value, etc.) to determine the cause of the malfunction.
Assume that an electrical
system wiring harness or
connector is the cause of the
malfunction. Shake the wirQ002317
ing
by
hand
to
check
whether a malfunction occurs and a DTC is generated.
Assume that an electrical system female connector terminal is
the cause of the malfunction and verify that the connection
points are not defective.
Recommended Tool: KOWA Precision Handling
Feeler Gauge Set (KLM-10-20)
Depending on the terminal, a matching
size may not be available
Insert the male terminal that
matches the shape of the
female terminal and check
for looseness.
Q002318
Use a dryer to heat the
accelerator pedal position
sensor and other electronic
components.
Q002319
Check
for
changes in the voltage value
(resistance value).
< ATTENTION >
• Do not exceed 60×C (still touchable by hand) when
heating.
• Do not remove the component cases and add heat
directly to electronic parts.
Verify whether malfunction symptoms occur under heavy
engine loads (headlights, A/C, wiper, etc. switches ON.)
Repair Section
2– 111
Malfunction Symptom
Idle Speed,
Action
Fully Discharged Battery
Engine will
not Start
Engine Stall,
Sputtering,
Poor Acceleration
If any commercial electrical products have been installed,
remove such products and verify whether the malfunction
Yes
Yes
Yes
No
Yes
Yes
symptoms occur.
If it is likely that the malfunction occurs in rainy or high-
Mist State
temperature weather, spray
the vehicle with water and
Q002320E
verify whether the malfunc-
tion occurs.
< ATTENTION >
• Do not spray water directly into the engine compartment. Spray water in mist form on all surfaces
of the radiator to indirectly change temperature
and humidity.
• Do not spray water directly on electrical parts.
2– 112
Repair Section
3. DIAGNOSTIC TOOL USE (TOYOTA VEHICLE EXAMPLE)
3.1 Diagnostic Trouble Code (DTC) Reading
(1) DST-2
• The DST-2 can read DTCs in both the normal and check mode. Compared to the normal mode, the check
mode has higher malfunction detection sensitivity. Check mode is used when detection is not possible in
normal mode, regardless of the assumed abnormality.
(2) DTC check (code reading using the DST-2)
• Connect the DST-2 to the DLC3 check connector.
• View the “DTC check” screen by operating the DST-2 in accordance with the displayed instructions. To
verify a DTC, select either the normal or check mode.
(3) DTC memory erasure (using the DST-2)
• To erase DTC codes, follow the instructions shown on the display to view the “DTC and Freeze Data Erasure” screen.
Diagnostic Trouble Code (ECD Erasure)
This will erase the DTC and freeze frame data.
Erase OK?
No : - OK : +
Q000916E
< ATTENTION >
• If the DTC cannot be erased, cycle the ignition switch OFF and back ON, and then perform code
erasure again.
• Do not erase a DTC using the DST-2 until the cause of the malfunction is clear.
Repair Section
2– 113
3.2 Active Test
z To perform the active test, follow the instructions displayed on the DST-2 to view the "Active Test" screen.
Item Name
Content
Control Conditions
A/C Cut
Possible to turn the magnetic clutch on and off
-
EGR VSV
Possible to turn the E-VRV on and off
When at idle speed
TC Terminal On Displays all combination meter warning diagnosis at once
High-Pressure
Fuel
Initiates the high-pressure fuel system check
Approximately 2000 rpm
(Fuel pressure: 160 MPa)
Syste
Check
Power Balance Discontinues injection to each cylinder individually: #1, #2, When
(Injection
the
vehicle
is
Dis- #3, #4 (Not possible to discontinue injection to multiple cylin- stopped and the engine is
continuation)
ders)
running
3.3 Supply Pump Initialization Procedure
[ REFERENCE ]
• Perform after replacing the supply pump and/or the engine ECU.
• If the engine is defective or stalls immediately after startup, initialize the engine ECU's learned values. The
engine can be initialized through the intelligent tester, or by short circuiting DLC3 terminals.
• If the engine starts normally, initialization is not necessary. Perform steps (i) and (j) only.
(1) When using intelligent tester :
• a. Connect the intelligent tester to the DLC3.
• b. Turn the ignition switch on.
< ATTENTION >
Do not start the engine.
• c. Turn the intelligent tester on.
• d. Enter the following menus: Power train / Engine / Utility / Supply Pump Initialization.
• e. Press “Next”.
Q003353E
2– 114
Repair Section
• f. Press “Next”.
Q003354E
• g. Press “Exit”.
Q003355E
• h. Start the engine to check if the initialization is complete. If the engine cannot be started, repeat the initialization procedures from the beginning.
• i. Idle the engine for at least one minute under the following conditions:
•Water temperature is 60 °C (140 °F) or more
•Fuel temperature is 20 °C (68 °F) or more
< ATTENTION >
Do not race the engine immediately after starting. After idling the engine, racing is acceptable.
[ REFERENCE ]
• The water temperature can be estimated by touching the outlet hose.
• The fuel temperature can be estimated by using the ambient temperature as a substitute.
• If the water temperature is difficult to estimate, use the intelligent tester and enter the following menus:
Power train / Engine / Data List / Coolant Temp
• j. Initialization is complete.
Repair Section
(2) When not using intelligent tester :
• a. Using STT, connect the terminals TC and CG of the DLC3.
STT: 09843-18040
• b. Turn the ignition switch ON.
• c. Wait three minutes.
• d. Turn the ignition switch off.
• e. Remove the connection from terminals TC and CG.
• f. Start the engine.
If the engine cannot be started, repeat the initialization procedures from the beginning.
• g. Idle the engine for at least one minute under the following conditions:
•Water temperature is 60 °C (140 °F) or more
•Fuel temperature is 20 °C (68 °F) or more
< ATTENTION >
• Do not race the engine immediately after .
• After idling the engine, racing is acceptable.
[ REFERENCE ]
• Water temperature can be estimated by touching the outlet hose.
• Fuel temperature can be estimated by using the ambient temperature as a substitute.
• h. Initialization is complete.
2– 115
2– 116
Repair Section
3.4 Injector ID Code Registration
(1) After replacing an injector, input the injector compensation code into the engine ECU as
follows:
< ATTENTION >
• When an injector is replaced, input the injector compensation code into the engine ECU. When the
engine ECU is changed, input all of the existing injector compensation codes into the new engine
ECU.
• Injector compensation codes are unique, 30-digit, alphanumeric values printed on the head portion
of each injector. If an incorrect injector compensation code is input into the engie ECU, the engine
may rattle or engine idling may become rough. In addition, engine failure may occur, shortening
engine life.
• a. Connect the intelligent tester to the DLC3.
• b. Turn the ignition switch on.
• c. Turn the tester on.
< ATTENTION >
Do not start the engine.
[ REFERENCE ]
The injector compensation code is imprinted on the head of each injector.
Example:
Injector
Compensation Code
Q003356E
• d. Enter the menu options in this order: Power train / Engine / Utility / Injector Compensation.
• e. Press “Next”.
Q003378E
Repair Section
• f. Press “Next” again to proceed.
Q003379E
• g. Select "Set Compensation Code".
• h. Press “Next”.
Q003380E
• i. Select the number of the cylinder corresponding to the injector compensation code to be read.
• j. Press “Next”.
Q003381E
2– 117
2– 118
Repair Section
• k. Register the compensation code.
i. Press “Input”.
Q003381E
ii. Manually input the cylinder compensation code using the keyboard on the tester screen. The code is a
30-digit, alphanumeric value imprinted on the injector head.
Q003383E
[ REFERENCE ]
Each injector compensation code is unique. Input the correct compensation code into each cylinder selected on the tester.
iii. Confirm that the compensation code is correct for the selected cylinder, and then press “OK”.
Repair Section
2– 119
• l. Check that the compensation code displayed on the screen is correct, through comparison it with the 30-digit alphanumeric value on the head of the injector.
Q003384E
< ATTENTION >
If an incorrect injector compensation code is input into the engine ECU, the engine may rattle or
engine idling may become rough. In addition, engine failure may occur, shortening engine life.
[ REFERENCE ]
If a wrong compensation code was inputted or read, return to the input value screen by pressing “Input”.
The saving process may fail due to a problem with the wiring harness or a bad connection with the DLC3.
Check the wiring harness and the DLC3 connection. If no problem is found with either wiring harness or
connection, the engine ECU may be malfunctioning. Check the engine ECU and repeat this operation.
• m. Press “Next” to set the compensation code to the engine ECU.
[ REFERENCE ]
• If the setting process fails, the compensation code may be incorrect. Check the compensation code again.
• If the attempted compensation code is correct, a problem with the wiring harness or a bad connection with
the DLC3 may have caused the failure. Check the wiring harness and the DLC3 connection. If no problem
is found with either the wiring harness or connection, the engine ECU may be malfunctioning. Check the
engine ECU and restart this operation.
Repair Section
2– 120
• n. To continue with other compensation code registrations, press ”Next”. To finish the registration, press “Cancel”.
Q003385E
• o. Turn the ignition switch off and then turn the tester off. Next, turn the tester off, and then turn the ignition
switch off.
• p. Wait for at least 30 seconds.
• q. Turn the ignition switch on, and then turn the tester on.
• r. Clear DTC P1601/89 stored in the engine ECU using the tester.
(2) After replacing the engine ECU, input all injector compensation codes into the new engine ECU as follws:
< ATTENTION >
• When an injector is replaced, input the injector compensation code injector into the engine ECU.
When the engine ECU is changed, input all of the existing compensation codes into the new engine
ECU.
• Injector compensation codes are unique, 30-digit, alphanumeric values printed on the head of each
injector. If an incorrect injector compensation code is input into the engine ECU, the engine may
rattle or engine idling may become rough. In addition, engine failure may occur, shortening engine
life.
[ REFERENCE ]
The following operation is available with engine ECUs that can transmit the registered injector compensation codes to the intelligent tester.
• a. Connect the intelligent tester to the DLC3.
• b. Turn the ignition switch on.
Repair Section
2– 121
• c. Turn the tester on.
< ATTENTION >
Do not start the engine.
[ REFERENCE ]
The injector compensation code is imprinted on the head of each injector.
Example:
Injector
Compensation Code
Q003356E
• d. Enter the menu options in this order: Power train / Engine / Utility / Injector Compensation.
• e. Press “Next”.
Q003378E
• f. Press “Next” again to proceed.
Q003379E
2– 122
Repair Section
• g. Select “Read Compensation Code”.
• h. Press “Next”.
Q003386E
• i. Select the number of the cylinder corresponding to the injector compensation code to be read.
• j. Press “Next”.
Q003381E
[ REFERENCE ]
The reading process may fail due to a problem with the wiring harness or a bad connection with the DLC3.
Check the wiring harness and the DLC3 connection. If no problem is found with either the wiring harness
or connction, the engine ECU may be malfunctioning. Check the engine ECU and restart this operation.
• k. Check that the injector compensation code (30-digit alphanumeric value) is displayed on the tester
screen.
Repair Section
2– 123
• l. Press “Save”.
Q003387E
• m. Check that the compensation code displayed on the tester screen is correct.
• n. Press “Save” or “Replace” to save the injector compensation code.
When no injection compensation code
for the cylinder exists in the tester
When another injector compensation
code for the cylinder exists in the tester
Q003388E
[ REFERENCE ]
• The existing compensation code is overwritten with the new compensation code, and is deleted from the
tester.
• The saving process may fail due to a problem with the wiring harness or a bad connection with the DLC3.
Check the wiring harness and the DLC3 connection. If no problem is found with either the wiring harness
or connection, the engine ECU may be malfunctioning. Check the engine ECU and restart this operation.
2– 124
Repair Section
• o. To save other injector compensation codes for other cylinders, press “Next”. To finish this operation, press “Cancel”.
Q003387E
• p. Turn the ignition switch off.
• q. Turn the tester off.
• r. Replace the engine ECU.
• s. Connect the intelligent tester to the DLC3.
• t. Turn the ignition switch on.
• u. Turn the tester on.
< ATTENTION >
Do not start the engine.
[ REFERENCE ]
The injector compensation code is imprinted on the head of each injector.
Example:
Injector
Compensation Code
Q003356E
• v. Enter the menu options in this order: Power train / Engine / Utility / Injector Compensation.
Repair Section
2– 125
• w. Press “Next”.
Q003378E
• x. Press “Next” again to proceed.
Q003379E
• y. Select “Set Compensation Code”.
• z. Press “Next”.
Q003380E
• aa. Select the number of the cylinder corresponding to the injector compensation code to be read.
2– 126
Repair Section
• ab. Press “Next”.
Q003381E
• ac. Check that the compensation code displayed on the screen is correct, through comparison with the
30-digit alphanumeric value on the head of the injector.
Q003384E
< ATTENTION >
If an incorrect injector compensation code is input into the engine ECU, the engine may rattle or
engine idling may become rough. In addition, engine failure may occur, shortening engine life.
[ REFERENCE ]
If a wrong compensation code was input or read, return to the input value screen by pressing “Input”. The
saving process may fail due to a problem with the wiring harness or a bad connection with the DLC3. Check
the wiring harness and the DLC3 connection. If no problem is found with either the wiring harness or connection, the engine ECU may be malfunctioning. Check the engine ECU and repeat this operation.
Repair Section
2– 127
• ad. Press “Next” to set the compensation code to the engine ECU.
[ REFERENCE ]
• If the setting fails, the compensation code may be incorrect. Check the compensation code again.
• If the attempted compensation code is correct, a problem with the wiring harness or a bad connection with
the DLC3 may have caused the failure. Check the wiring harness and the DLC3 connection. If no problem
is found with either the wiring harness or connection, the engine ECU may be malfunctioning. Check the
engine ECU and restart this operation.
• ae. To continue with other compensation code registrations, press “Next”. To finish the registration, press
“Cancel”.
Q003385E
• af. Turn the ignition switch off and then turn the tester off. Next turn the tester off, and then turn the ignition
switch off.
• ag. Wait for at least 30 seconds.
• ah. Turn the ignition switch on and then turn the tester on.
• ai. Clear DTC P1601/89 stored in the engine ECU using the tester.
Repair Section
2– 128
4. DIAGNOSIS BY SYSTEM
4.1 Intake System Diagnosis
Diagnostic Procedure
1
Check for air cleaner clogging and dirt.
NG
Clean or replace the air cleaner.
OK
2
Repair or replace the malfunctioning com-
Check the suction path for leaks.
• Suction path joint
NG
ponent.
• Suction pipes, hoses
OK
3
Repair or replace the malfunctioning com-
Check the diesel throttle, EGR, turbo.
• Check that the diesel throttle is not
NG
ponent.
stuck closed
• Check that the EGR is not stuck open
• Check that the turbo operates
OK
Normal
4.2 Fuel System Diagnosis
Diagnostic Procedure
1
Check the fuel quality and quantity.
• Check the amount of fuel in the tank.
NG
Add fuel or replace components (clean the
tank.)
• Check the fuel quality. Request engine
analysis from a third party as necessary.
Color (no color, brownish, milky)
Odor (kerosene, heavy oil, irritating odor)
Separation of materials (water, foreign matter)
Viscosity (high/low viscosity, wax consistency)
OK
2
Check the primary filter and sedimenter.
• Check for primary filter clogging, dirt
• Check the sedimenter water volume
NG
Replace the filter, drain water from the sedimenter.
Repair Section
2– 129
OK
3
Check for filter (supply pump inlet) clogging.
NG
Clean or replace the fuel filter and fuel piping.
OK
4
Check that the fuel piping is not damaged,
clogged, and/or poorly connected. If a defi-
NG
Repair or replace the fuel piping.
ciency is found, repair the piping as necessary.
OK
5
Check the inside of the fuel tank. (Check
for tank modification/additions, position of
the fuel pipe inlet/outlet, clogging and
holes.)
• Check the tank for modifications or
additions. Compare to an unmodified
tank, or consult with the user.
Fuel inlet/outlet position, tank piping
Foreign matter in the tank, water separation
Tank-internal Zinc (Zn) cladding
• Check the tank internal fuel piping for
the following:
9 Inlet/outlet position (below position
"E".)
9 Inlet clogging, bent or deformed piping (crushed pipe)
9 Crushed piping connections
OK
NG
Restore the fuel tank.
2– 130
6
Repair Section
Check the tank-external fuel flow path.
(Check for crushed hose, clogging, air
NG
Repair or replace the hoses.
introduction at hose connections.)
• Check the hoses.
Crushed around bands, over-bending
9 Pinched or crushed by other parts
• Check for air introduction through connection points.
Looseness
9 Hose deterioration. (Check by hand/
visually that there is no rubber hardening/splitting.)
< ATTENTION >
Be cautious when vacuum pressure is present, as air will be
drawn into the hose.
OK
7
Check that the oil level has not increased
(engine-internal leaks.)
NG
Check the engine.
• Check that the oil quantity has not
increased on the oil level gauge.
OK
8
Check for engine-external fuel leaks, such
as from the high-pressure piping and CRS
components such as the injectors, supply
pump, and rail. (Refer to "(2) Fuel leak
check".)
• Connect the DST-2 to the diagnostic
connector. Initiate the "High-Pressure
Fuel System Check" within the active
test.
• Visually check and specify areas leaking fuel.
< ATTENTION >
In the event of a large fuel leak
downstream of the flow damper,
be aware that fuel flow will stop
and the leak will cease due to
flow damper operation.
NG
Restore leaking sections of the high-pressure piping, and replace any leaking components.
Repair Section
2– 131
OK
Bleed air from the fuel. → Complete
(1) Fuel pressure test procedure
• Connect the DST-2 to the vehicle-side test connector.
With the vehicle idling, verify the rail pressure displayed on the DST-2.
System selection screen: Rail, ECU Data Monitor (Display: "Common Rail Pressure")
Item Name (Abbreviation)
Common Rail Pres-
Items of Importance
Explanation
Check Conditions
Reference Value
mality
• Displays the fuel Following
engine is rotating
rail.
to
played
dis- nals (rail assembly)
is
within
a
range of 30 MPa to
• Display range: 0
MPa
fuel PCR1, PCR2 sig-
engine Rail-internal
pressure in the warm-up, when the pressure
sure (CRP)
During an Abnor-
160 MPa.
255
MPa
(2) Fuel leak check
• Connect the DST-2 to the vehicle-side test connector.
• With the vehicle idling, initiate the active test by following the instructions on the DST-2 display.
System selection screen: TCCS, Active Test
Item Name
Description
High-Pressure Fuel System Check Raise engine rotational speed to
Control Conditions
• Following
engine
warm-up,
2000 rpm, and then use the active
when the engine is at idle
test to place the fuel inside the rail
speed
under high pressure.
< ATTENTION >
Engine rotational speed
• The vehicle speed sensor is
operating normally, and speed
is 0 km/h.
cannot be set by stepping on the accelerator
pedal.
• Verify that there are no fuel system leaks during the active test (when fuel pressure is being applied to the rail.)
Repair Section
2– 132
4.3 Basics of Electrical/Electronic Circuit Checks
(1) ECU terminal voltage and waveform measurements
• When measuring the voltage and resistance of each terminal, insert the multimeter probe into the rear side of the
wiring harness connector. If connectors are too small for the probe to be inserted easily, insert a fine metal wire into
the rear of the connector and touch the wire to the probe.
[ REFERENCE ]
The number of each terminal can be seen from the rear side of the wiring harness.
Engine ECU Side
Ground
Wiring Harness
Side
Ground
Ground
Q002326E
(2) Open circuit check
• When dealing with a wiring harness open circuit like that depicted in diagram 1, check continuity and/or voltage to
determine the location of the open circuit.
Diagram 1
Engine ECU
Sensor
1
2
C
Open
Circuit
1
1
1
2
2
2
B
A
Q002327E
Repair Section
2– 133
Continuity Check
1) Remove connectors "A" and "C", and then measure
Diagram 2
resistance between the two.
Engine
ECU
Standard
Value
1
Sensor
1
2
2
C
1 Ω or less
2
B
[ REFERENCE ]
A
Measure resistance while gently shaking the wiring
Q002328E
harness up and down, and side-to-side.
2) As shown in diagram 2, there is no continuity (open
circuit) between terminal 1 of connector "A" and terminal 1 of connector "C". However, there is continuity
between terminal 2 of connector "A" and terminal 2 of
connector "C". Therefore, there is an open circuit between terminal 1 of connector "A" and terminal 1 of
connector "C".
3) Remove connector "B" and measure the connector
Diagram 3
Engine
ECU
Sensor
resistance.
4) As shown in diagram 3, there is continuity between
terminal 1 of connector "A" and terminal 1 of connector "B1". However, there is no continuity (open circuit)
1
2
C
1
1
2
2
B2 B1
1
between terminal 1 of connector "B2" and terminal 1
2
of connector "C". Therefore, there is an open circuit
A
Q002329E
between terminal 1 of connector "B2" and terminal 1
of connector "C".
Repair Section
2– 134
Voltage Check
1) For the circuit that applies voltage to the ECU connec-
Diagram 4
tor terminals, check for an open circuit by performing
a voltage check.
0V
Sensor
C
1
2
2) As shown in diagram 4, with all connectors connect-
5V
ed, measure the voltage for the ECU 5 V output termi-
5V
B
1
2
A
1
2
nal between the body ground and terminal 1 of
connector "A". Next measure voltage for terminal 1 of
connector "B" and terminal 1 of connector "C" in the
Q002330E
same fashion.
3) The faulty circuit and measurement results are shown
below.
• Voltage between terminal 1 of
connector "A" and the body
ground is 5 V.
• Voltage between terminal 1 of
Measurement Results
connector "B" and the body
ground is 5 V.
• Voltage between terminal 1 of
connector "C" and the body
ground is 0 V.
There is an open circuit in the wir-
Faulty Item
ing harness between terminal 1 of
connector "B" and terminal 1 of
connector "C".
(3) Short circuit check
• As shown in diagram 5, if there is a short in the wiring harness ground, perform a "Ground Continuity Check" to determine the cause of the short.
Diagram 5
Engine ECU
Sensor
Short
Circuit
%
$
#
Q002331E
Repair Section
2– 135
Ground Continuity Check
1) Remove connector "A" and connector "C", and then
Diagram 6
measure the resistance respectively between terminals 1 and 2 of connector "A" and ground.
Engine
ECU
1
2
Sensor
1
2
C
B
1 Ω or less
Standard Value
1
2
[ REFERENCE ]
A
Measure resistance while gently shaking the wiring
Q002332E
harness up and down, and side-to-side.
2) As shown in diagram 6, there is continuity between
terminal 1 of connector "A" and the body ground
(short circuit). However, there is no continuity between terminal 2 of connector "A" and the body
ground. Therefore, there is a short circuit between terminal 1 of connector "A" and terminal 1 of connector
"C".
3) Remove connector "B" and measure the resistance
Diagram 7
Engine
ECU
between terminal 1 of connector "A" and the body
ground, and between terminal 1 of connector "B2" and
the body ground.
Sensor
4) The faulty circuit and measurement results are shown
1
2
C
1
1
2
2
B2 B1
1
below.
2
A
Q002333E
Measurement Results
• There is no continuity between
terminal 1 of connector "A" and
the body ground.
• There is continuity between terminal 1 of connector "B2" and
the body ground.
Faulty Item
There is a short circuit between terminal 1 of connector "B2" and terminal 1 of connector "C".
2– 136
Repair Section
(4) Connector connection fault verification method
• Simultaneously perform the data monitor and connector voltage measurements.
Ex.) Coolant temperature sensor
1. Read the "Coolant Temperature Output Voltage" value using the DST-2 data monitor.
2. Measure the voltage directly from the corresponding ECU terminal.
If "1" is unsatisfactory and "2" is satisfactory, the connector connection is judged as faulty.
Since some malfunctions only occur intermittently, measure voltage while pulling and shaking the
wires in order to try to get the malfunction to reoccur.
Voltage Measurement
No.2 - 34P
35
62
No.5 - 31P
41
137
69
162
143
167
Q002334E
Repair Section
2– 137
4.4 Engine ECU Input/Output Signal Check Method
z The following describes the method to check engine ECU input and output signals. The TOYOTA HIACE
and REGIUS ACE are used as examples.
(1) ECU terminal positions and standard values
• The standard values for each terminal are listed below.
Terminal (Signal)
Input/Out-
Measurement Conditions
put
Standard (V)
BATT ↔ E1 [C2 ↔ B7]
Input
Normal
9-14
+B ↔ E1 [D1 ↔ B7]
Input
Engine stopped and ignition switch on
9-14
VC ↔ E2 [A18 ↔ A28]
Output
Engine stopped and ignition switch on
4.5-5.5
PIM ↔ E2 [B28 ↔ A28]
Input
On level ground, and 40 kPa of vacuum
1.3-1.9
PIM ↔ E2 [B28 ↔ A28]
Input
When open to atmosphere (When atmospheric
pressure is 101.3 kPa)
2.4-3.1
On level ground, and 70 kPa of vacuum (when
PIM ↔ E2 [B28 ↔ A28]
Input
an absolute pressure of 170 kPa is being
3.7-4.3
applied)
VPA ↔ EPA [D22 ↔ D28]
Input
Accelerator fully closed
0.75-0.85
VPA ↔ EPA [D22 ↔ D28]
Input
Accelerator fully open
3.01-3.47
VPA2 ↔ EPA2 [D23 ↔
D29]
VPA2 ↔ EPA2 [D23 ↔
D29]
VCPA ↔ EPA [D26 ↔
D28]
VCP2 ↔ EPA2D [27 ↔
D29]
Input
Input
Output
Output
Accelerator fully closed
Accelerator fully open
Engine stopped and ignition switch on
Engine stopped and ignition switch on
1.55-1.65
3.81-4.27
4.5-5.5
4.5-5.5
Pulse emis-
SPD ↔ E1 [C17 ↔ B7]
Input
When driving at approximately 20 km/h
sion (Waveform 1)
THW ↔ E2 [A19 ↔ A28]
THA ↔ E2 [A31 ↔ A28]
THIA ↔ E2 [A20 ↔ A28]
Input
Input
Input
Coolant temperature: 60 to 120 °C (when warming up)
Intake air temperature: 0 to 80 °C (when warming up)
Intake air temperature: 0 to 80 °C(when warming up)
0.1-1.0
0.5-3.5
0.5-3.5
PCR1 ↔ E2 [A26 ↔ A28]
Input
After warm-up, when the engine is at idle speed
1.3-1.8
THF ↔ E2 [A29 ↔ A28]
Input
Ignition switch on (when cold)
0.5-3.4
THF ↔ E2 [A29 ↔ A28]
Input
Fuel temperature: 20 °C
2.0-2.7
2– 138
Repair Section
Terminal (Signal)
Input/Output
Measurement Conditions
Standard (V)
Pulse emis-
PCV+ ↔ E1 [A2 ↔ B7]
Input
After warm-up, when the engine is at idle speed
sion (Waveform 2)
Pulse emis-
PCV- ↔ E1 [A1 ↔ B7]
Input
After warm-up, when the engine is at idle speed
sion (Waveform 2)
Pulse emis-
#1 ↔ E1 [A24 ↔ B7]
Output
After warm-up, when the engine is at idle speed
sion (Waveform 3)
Pulse emis-
#2 ↔ E1 [A23 ↔ B7]
Output
After warm-up, when the engine is at idle speed
sion (Waveform 3)
Pulse emis-
#3 ↔ E1 [A22 ↔ B7]
Output
After warm-up, when the engine is at idle speed
sion (Waveform 3)
Pulse emis-
#4 ↔ E1 [A21 ↔ B7]
Output
After warm-up, when the engine is at idle speed
sion (Waveform 3)
Pulse emis-
INJF ↔ E1 [A25 ↔ B7]
Input
After warm-up, when the engine is at idle speed
sion (Waveform 4)
Pulse emis-
NE+ ↔ NE- [A27 ↔ A34]
Input
After warm-up, when the engine is at idle speed
sion (Waveform 5)
Pulse emis-
G+ ↔ G- [B23 ↔ B31]
Input
After warm-up, when the engine is at idle speed
sion (Waveform 5)
EGR ↔ E1 [B9 ↔ B7]
EGR ↔ E1 [B9 ↔ B7]
Output
Output
Engine stopped and ignition switch on
EGR on (after warm-up, and engine rotational
speed is maintained at 1500 rpm)
9-14
Pulse emission (Waveform 6)
Pulse emis-
LUSL ↔ E1 [B4 ↔ B7]
Output
When at idle speed
sion (Waveform 7)
VLU ↔ E2 [B29 ↔ A28]
Input
EGLS ↔ E2 [B33 ↔ A28]
Input
GREL ↔ E1 [D15 ↔ B7]
Output
GREL ↔ E1 [D15 ↔ B7]
Output
GIND ↔ E1 [D14 ↔ B7]
Output
Engine stopped, and ignition switch on (Throttle
position: 70 °)
Ignition switch on
When cranking
When at idle speed (Over 10 minutes has
elapsed since engine start)
Ignition switch on, glow indicator light on
3.0-4.0
0.6-1.4
9-14
0-1.5
0-3
Repair Section
Input/Out-
Terminal (Signal)
put
2– 139
Measurement Conditions
Standard (V)
After warm-up, when the engine is at idle speed
9-14
GIND ↔ E1 [D14 ↔ B7]
Output
W ↔ E1 [D12 ↔ B7]
Output
W ↔ E1 [D12 ↔ B7]
Output
STA ↔ E1 [D7 ↔ B7]
Input
When cranking
NSW ↔ E1 [D6 ↔ B7][*1]
Input
Shift lever in "P" or "N" position
0-3
NSW ↔ E1 [D6 ↔ B7][*1]
Input
Shift lever in a position other than "P" or "N"
9-14
IGSW ↔ E1 [D9 ↔ B7]
Input
Engine stopped and ignition switch on
9-14
MREL ↔ E1 [D8 ↔ B7]
Output
Engine stopped and ignition switch on
9-14
MREL ↔ E1 [D8 ↔ B7]
Output
IREL ↔ E1 [D10 ↔ B7]
Output
When at idle speed
0-1.5
IREL ↔ E1 [D10 ↔ B7]
Output
When the ignition switch is off
9-14
TACH ↔ E1 [D4 ↔ E1]
Output
After warm-up, when the engine is at idle speed
When the Malfunction Indicator Lamp (MIL) is lit
(when the ignition switch is on)
When at idle speed (MIL is not lit)
Engine stopped, and at least 10 minutes has
elapsed since ignition switch was turned off
0-3
9-14
At least 6 V
0-1.5
Pulse emission (Waveform 8)
TC ↔ E1 [D11 ↔ B7]
Output
TC ↔ E1 [D11 ↔ B7]
Output
THB
↔ E2
[A33
↔
[A10
↔
Input
Ignition switch on
Open circuit between DLC3 connector terminals
13 (TC) and 4 (CG)
Battery fluid temperature: 10 to 80 °C
A28][*2]
RLO
↔ E1
B7][*2]
LOUT
0-3
0.3-4.0
Pulse emis-
Output
When at idle speed
sion (Waveform 9)
↔
E1
[C3
↔
↔ E1
[C3
↔
B7][*2]
LOUT
9-14
B7][*2]
Output
Output
When the charge light is lit
When the charge light is not lit
0-3
9-14
Pulse emis-
ALT ↔ E1 [A8 ↔ B7]
Input
When at idle speed
sion (Waveform 10)
RTHW ↔ E2 [D20 ↔ B8]
FAN ↔ E1 [A13 ↔ B7]
Input
Output
Radiator water temperature: -20 to 80 °C
When the electric fan (sub side) is operating
0.5-4.5
0-1.5
Pulse emis-
RFC ↔ E1 [A12 ↔ B7]
Output
When the electric fan is operating
sion (Waveform 11)
Pulse emis-
RFC2 ↔ E1 [A11 ↔ B7]
Output
When the electric fan is operating
sion (Waveform 11)
Repair Section
2– 140
Terminal (Signal)
Input/Out-
Measurement Conditions
put
Standard (V)
Pulse emis-
THWO ↔ E1 [D2 ↔ B7]
Output
When at idle speed
sion (Waveform 12)
CAN+ ↔ CAN- [C22 ↔ Input/Out- At least 10 minutes have elapsed since the igniC21] [*1]
put
tion switch was turned off
CANH ↔ CANL [C24 ↔ Input/Out- At least 10 minutes have elapsed since the igniC23]
put
tion switch was turned off
54-69 Ω
54-69 Ω
STP ↔ E1 [C15 ↔ B7]
Input
Stop light switch is on
7.5-14
STP ↔ E1 [C15 ↔ B7]
Input
Stop light switch is off
0-1.5
ST1 ↔ E1 [C14 ↔ B7]
Input
Stop light switch is on
0-1.5
ST1 ↔ E1 [C14 ↔ B7]
Input
Stop light switch is off
7.5-14
E1 ↔ Body Ground (B7
↔ Body Ground)
E2 ↔ Body Ground (A28
↔ Body Ground)
E01 ↔ Body Ground (A7
↔ Body Ground)
E02 ↔ Body Ground (A6
↔ Body Ground)
E0M ↔ Body Ground
(D16 ↔ Body Ground)
EC ↔ Body Ground (C6
↔ Body Ground)
Ground
Normal (continuity test)
Ground
Normal (continuity test)
Ground
Normal (continuity test)
Ground
Normal (continuity test)
Ground
Normal (continuity test)
Ground
Normal (continuity test)
Connector A
Connector B
Connector C
Continuity
(5 Ω or less)
Continuity
(5 Ω or less)
Continuity
(5 Ω or less)
Continuity
(5 Ω or less)
Continuity
(5 Ω or less)
Continuity
(5 Ω or less)
Connector D
Connector A
Connector B
Connector C
Connector D
*1: Automatic transmission vehicles only. *2: Cold specification vehicles only.
Engine ECU Terminal Layout Diagram
Q002695E
Repair Section
2– 141
(2) Oscilloscope waveforms
[ REFERENCE ]
The following oscilloscope waveforms are reference examples. Noise and chattering waveforms have
been omitted.
• a. Waveform 1: Vehicle speed (meter input)
Item
Description
Measurement
SPD
Terminals
Ground
Instrument
Setting
E1
2V/DIV‫ޔ‬20ms/DIV
Conditions When driving at approximately 20 km/h
Q002696E
[ REFERENCE ]
• As vehicle speed decreases, the wave period shortens.
• As vehicle speed decreases, the wave amplitude increases.
• b. Waveform 2: SCV actuation voltage
Item
Description
Measurement CH1: PCV+
Terminals
CH2: PCV-
E1
E1
Instrument
Setting
CH1: 10V/DIV, 5ms/DIV
CH2: 500mv/DIV, 5ms/DIV
Conditions
After warm-up, when the engine is at idle speed
Q002697E
• c. Waveform 3: Injector actuation signal
Item
Description
CH1 : #1
Measurement CH2 : #2
Terminals CH2 : #3
Ground
CH2 : #2
Ground
Ground
Instrument
Setting
E1
E1
E1
E1
5V/DIV, 20ms/DIV
Conditions After warm-up, when the engine is at idle speed
Ground
[ REFERENCE ]
As engine rotational speed increases, the period of each wave shortens.
Q002698E
2– 142
Repair Section
• d. Waveform 4: Injector feedback signal
Item
Description
Measurement
INJF
Terminals
Instrument
Setting
Ground
E1
2V/DIV, 1ms/DIV
Conditions After warm-up, when the engine is at idle speed
Q002699E
[ REFERENCE ]
As engine rotational speed increases, the wave period shortens.
• e. Waveform 5: Engine rotational speed signal (NE, TDC)
Ground
Item
Description
Measurement CH1 : NE+
Terminals CH2 : G+
Ground
Instrument
Setting
NEG-
5V/DIV, 20ms/DIV
Conditions After warm-up, when the engine is at idle speed
Q002700E
[ REFERENCE ]
• As engine rotational speed increases, the amplitude of each wave increases.
• As engine rotational speed increases, the wave period shortens.
• f. Waveform 6: EGR valve actuation signal
Item
Description
Measurement
EGR
Terminals
Ground
E1
Instrument
Setting
5V/DIV, 500 s/DIV
Conditions
EGR on (after warm-up, and engine
rotationalspeed is maintained at 1500 rpm)
Q002701E
Repair Section
2– 143
• g. Waveform 7: Diesel throttle actuation signal
Item
Description
Measurement
LUSL
Terminals
Ground
E1
Instrument
Setting
1V/DIV, 2ms/DIV
Conditions
When at idle speed
Q002702E
• h. Waveform 8: Engine rotational speed signal (tachometer input)
Description
Item
Ground
Measurement
TACH
Terminals
Instrument
Setting
E1
5V/DIV, 20ms/DIV
Conditions After warm-up, when the engine is at idle speed
Q002703E
[ REFERENCE ]
As engine rotational speed increases, the wave period shortens.
• i. Waveform 9: Alternator voltage regulation command signal
Item
Description
Measurement
RLO
Terminals
Ground
E1
Instrument
Setting
2V/DIV, 20ms/DIV
Conditions
When at idle speed
Q002704E
2– 144
Repair Section
• j. Waveform 10: Alternator output monitor
Item
Description
Measurement
ALT
Terminals
Ground
E1
Instrument
Setting
5V/DIV, 5ms/DIV
Conditions
When at idle speed
Q002705E
• k. Waveform 11: Electric fan actuation signal
Item
Ground
Ground
Description
Measurement RFC
Terminals RFC2
E1
E1
Instrument
Setting
2V/DIV, 500 s/DIV
Conditions
When the electric fan is operating
Q002706E
• l. Waveform 12: Meter coolant temperature signal
Item
Description
Measurement
THWO
Terminals
Ground
E1
Instrument
Setting
5V/DIV, 0.1ms/DIV
Conditions
When at idle speed
Q002707E
[ REFERENCE ]
"A" changes according to coolant temperature.
Coolant Temperature
A
30 °C
16 ms
90 °C
278.5 ms
At least 120 °C
385 ms
Repair Section
2– 145
5. TROUBLESHOOTING
5.1 Troubleshooting According to Malfunction Symptom (for TOYOTA Vehicles)
(1) Malfunction Indicator Lamp (MIL) is lit.
Description
The check engine warning light is lit when the engine is running, or before the engine is started.
Possible Cause
The DTC is recorded in the engine ECU.
Clogged air cleaner element
1
Connect the DST-2 and read the DTC.
OK
Troubleshoot the corresponding DTC.
NG
Inspect the check engine warning light circuit.
2– 146
Repair Section
(2) The engine is hard to start.
Description
The starter turns at normal speed, but the engine takes too long to start.
Possible Cause
• Start signal circuit
• Glow control system
• Crankshaft position sensor
• Engine ECU power supply circuit
• Injector
• Supply pump
• Cylinder recognition sensor
Clogged air cleaner element
1
Use the DST-2 to verify whether the coolant temperature is at the glow system operating
temperature.
In
addition,
NG
Repair the glow control system. (Refer to
the glow control system check procedure
issued by the vehicle manufacturer.)
verify
whether battery voltage is being supplied
to the glow plugs at the designated times.
OK
2
Use the DST-2 to monitor engine speed
while cranking the engine. Verify whether
NG
Check the crankshaft position sensor.
(Refer to the crankshaft position sensor
check procedure issued by the vehicle
engine speed is being correctly output.
manufacturer.)
OK
3
Verify the output waveform of the cylinder
recognition sensor. (Refer to the cylinder
NG
Repair or replace the cylinder recognition
sensor and/or the corresponding circuit.
recognition sensor check procedure issued
by the vehicle manufacturer.)
OK
4
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
5
Verify whether there is a start signal when
cranking the engine by checking the
engine ECU start signal terminal.
OK
NG
Repair the start signal circuit.
Repair Section
6
Check the engine ECU power supply.
(Refer to the engine ECU power supply cir-
NG
2– 147
Repair the engine ECU power supply.
cuit diagram issued by the vehicle manufacturer.)
OK
7
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the supply pump and
drive circuit.
2– 148
Repair Section
(3) The engine stalls when idling.
Description
The engine stalls after starting or when idling.
Possible Cause
• Crankshaft position sensor
• Engine ECU power supply circuit
• Injector
• Supply pump
• Engine cooling system
• Start signal circuit
Clogged air cleaner element
1
Verify that the engine is not overheated.
NG
Repair the engine cooling system.
OK
2
Check the crankshaft position sensor output waveform. (Refer to the crankshaft
NG
Repair or replace the crankshaft position
sensor and/or the corresponding circuit.
position sensor check procedure issued by
the vehicle manufacturer.)
OK
3
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
4
Verify whether there is a start signal when
cranking the engine by checking the
NG
Repair the start signal circuit.
engine ECU start signal terminal.
OK
5
Check the engine ECU power supply.
(Refer to the engine ECU power supply cir-
NG
Repair the engine ECU power supply.
cuit diagram issued by the vehicle manufacturer.)
OK
6
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
NG
Repair or replace the supply pump and
drive circuit.
Repair Section
OK
Troubleshooting complete
2– 149
2– 150
Repair Section
(4) The engine cranks normally, but does not start.
Description
The engine is cranked at the normal speed, but does not start.
Possible Cause
• Crankshaft position sensor
• Engine ECU power supply circuit
• Injector
• Supply pump
• Start signal circuit
Clogged air cleaner element
1
Use the DST-2 to verify whether the coolant temperature is at the glow system operating
temperature.
In
addition,
NG
Repair the glow control system. (Refer to
the glow control system check procedure
issued by the vehicle manufacturer.)
verify
whether battery voltage is being supplied
to the glow plugs at the designated times.
OK
2
Monitor engine speed while cranking the
engine. Verify whether engine speed is
NG
Check the crankshaft position sensor.
(Refer to the crankshaft position sensor
check procedure issued by the vehicle
being correctly output.
manufacturer.)
OK
3
Verify whether there is a start signal when
cranking the engine by checking the
NG
Repair the start signal circuit.
engine ECU start signal terminal.
OK
4
Check the engine ECU power supply.
(Refer to the engine ECU power supply cir-
NG
Repair the engine ECU power supply.
cuit diagram issued by the vehicle manufacturer.)
OK
5
Check each injector. (Refer to the injector
check procedure issued by the vehicle
manufacturer.)
OK
NG
Repair or replace the injector and/or the
corresponding circuit.
Repair Section
6
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
2– 151
Repair or replace the supply pump and
drive circuit.
2– 152
Repair Section
(5) Idle instability following engine start
Description
Idle speed after starting the engine is abnormal.
Possible Cause
• Injector
• Supply pump
• Fuel filter
• Engine ECU
• Rail pressure sensor
Clogged air cleaner element
1
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
2
Check the fuel filter.
NG
Replace the fuel filter.
OK
3
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
NG
Repair or replace the supply pump and
drive circuit.
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
4
Check the rail pressure sensor and the corresponding circuit. (Refer to the rail pressure sensor check procedure issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the rail pressure sensor
and the corresponding circuit.
Repair Section
2– 153
(6) The engine returns to idle speed too slowly, or does not return at all.
Description
The time required for the engine to return to idle speed is longer than normal, or the engine does not return
to idle speed.
Possible Cause
• Accelerator position sensor
• Injector
• Supply pump
Clogged air cleaner element
1
Perform the accelerator pedal position sensor function check. (Refer to the accelera-
NG
Repair or replace the accelerator position
sensor and/or the corresponding circuit.
tor position pedal sensor check procedure
issued by the vehicle manufacturer.)
OK
2
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
3
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the supply pump and
drive circuit.
2– 154
Repair Section
(7) Rough idle
Description
Idle speed fluctuates, causing the engine to vibrate.
Possible Cause
• Engine cooling system
• Crankshaft position sensor
• Engine
• Supply pump
• Injector
Clogged air cleaner element
1
Check parts that may be a source of abnormal engine vibration.
NG
Repair the engine.
OK
2
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
3
Verify that the engine is not overheated.
NG
Repair the engine cooling system.
OK
4
Check the crankshaft position sensor.
(Refer to the crankshaft position sensor
NG
Repair or replace the crankshaft position
sensor and/or the corresponding circuit.
check procedure issued by the vehicle
manufacturer.)
OK
5
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the supply pump and
drive circuit.
Repair Section
2– 155
(8) The engine stalls when decelerating.
Description
The engine suddenly stops when decelerating.
Possible Cause
• Engine cooling system
• Crankshaft position sensor
• Engine ECU power supply circuit
• Supply pump
• Injector
• Start signal circuit
Clogged air cleaner element
1
Verify that the engine is not overheated.
NG
Repair the engine cooling system.
OK
2
Check the crankshaft position sensor.
(Refer to the crankshaft position sensor
NG
Repair or replace the crankshaft position
sensor and/or the corresponding circuit.
check procedure issued by the vehicle
manufacturer.)
OK
3
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
4
Verify whether there is a start signal when
cranking the engine by checking the
NG
Repair the start signal circuit.
engine ECU start signal terminal.
OK
5
Check the engine ECU power supply.
(Refer to the engine ECU power supply cir-
NG
Repair the engine ECU power supply.
cuit diagram issued by the vehicle manufacturer.)
OK
6
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
NG
Repair or replace the supply pump and
drive circuit.
2– 156
Repair Section
OK
Troubleshooting complete
Repair Section
2– 157
(9) Poor engine output, poor acceleration
Description
Deficient engine performance.
Possible Cause
• EGR system
• Injector
• Mass Air Flow (MAF) meter
• Crankshaft position sensor
• Accelerator position sensor
• Boost pressure sensor
• Supply pump
• Start signal circuit
• Air cleaner, duct
Clogged air cleaner element
1
Check for air cleaner clogging and/or damage.
NG
Replace the air cleaner or repair the air
duct.
OK
2
Verify that the engine is not overheated.
NG
Repair the engine cooling system.
OK
3
Check the crankshaft position sensor.
(Refer to the crankshaft position sensor
NG
Repair or replace the crankshaft position
sensor and/or the corresponding circuit.
check procedure issued by the vehicle
manufacturer.)
OK
4
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
5
Verify whether there is a start signal when
cranking the engine by checking the
engine ECU start signal terminal.
OK
NG
Repair the start signal circuit.
2– 158
6
Repair Section
Check the MAF meter and the corresponding circuit. (Refer to the MAF meter check
NG
Repair or replace the MAF meter and/or
the corresponding circuit.
procedure issued by the vehicle manufacturer.)
OK
7
Check the Exhaust Gas Recirculation
(EGR) system. (Refer to the EGR system
NG
Repair or replace the EGR system.
check procedure issued by the vehicle
manufacturer.)
OK
8
Perform the accelerator pedal position sensor function check. (Refer to the accelera-
NG
Repair or replace the accelerator position
sensor and/or the corresponding circuit.
tor position pedal sensor check procedure
issued by the vehicle manufacturer.)
OK
9
Check the boost pressure sensor and the
corresponding circuit. (Refer to the boost
NG
Repair or replace the boost pressure sensor and/or the corresponding circuit.
pressure sensor check procedure issued
by the vehicle manufacturer.)
OK
10 Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the supply pump and
drive circuit.
Repair Section
2– 159
(10) Engine start failure (example for TOYOTA, HIACE, and REGIUS ACE)
Attention Points
• If replacing an injector assembly, always register the injector ID following replacement.
• If replacing the injection (supply) pump, always perform learning value initialization following replacement.
• If replacing the engine control computer, always perform injection (supply) pump learning value initialization, and register the injector IDs following replacement.
• Bleed the fuel piping, then begin troubleshooting.
Diagnostic Procedure
1
DTC Reading: Check for a DTC output.
Code Output
Refer to the DTC chart.
No Code
Output
2
ID Code Verification: Check whether the
injector ID codes are registered.
NG
Register the recorded ID codes.
OK
3
Cranking Check: Prepare the same model
vehicle for which no claim has been filed.
Check whether cranking is slow on the
malfunctioning vehicle compared to the
non-malfunctioning vehicle.
OK
NG
Check the battery and starter.
2– 160
4
Repair Section
DST-2 Data Reading: While cranking, use
the data monitor function to measure each
type of data.
When the engine is cold, check that engine
rotational speed (NE) is between 1000 to
NG
Proceed to step 15 (Glow System Check)
1500 rpm during initial combustion.
When the engine is warm, check that
engine rotational speed (NE) is between
NG
Proceed to step 17 (Fuel Intake System
Check)
900 to 1500 rpm during initial combustion.
When starting the vehicle and at idle,
check that the rail target pressure (PC) is
NG
1)
the
engine
Sensor Check) through 14 (Engine ECU
Replacement)
between 30 to 40 MPa under the following
conditions:
Proceed to steps 7 (Coolant Temperature
completely
warmed, 2) the A/C off and, 3) the shifter
in the "N" position.
When starting the vehicle, and at idle,
check that the rail fuel pressure (FP) is
NG
Proceed to step 11 (Rail Assembly Check)
between 30 to 40 MPa under the following
conditions:
1)
the
engine
completely
warmed, 2) the A/C off and, 3) the shifter is
in the "N" position.
Check whether there is a starter signal
(+B) input.
OK
NG
Proceed to step 20 (Starter Signal Check)
Repair Section
5
Compressor Check:
• a. Remove the cable from the battery
minus terminal.
• b. Remove the glow plug assembly
(refer to the relevant procedure.)
• c. Disconnect the connector for each
injector assembly.
• d. Connect the cable to the battery
minus terminal.
< ATTENTION >
Wrap electrical system wiring in
vinyl tape to prevent short circuits.
• e. Rotate the starter to discharge foreign matter from inside the cylinders.
• f. Insert the attachment into the glow
plug hole.
• g. Insert the compression gauge into
the attachment.
• h. Rotate the starter, and then measure
compression.
Q002708
< ATTENTION >
Use a completely charged battery to maintain engine rotational
speed at 250 rpm or higher.
• i. Remove the cable from the battery
minus terminal.
• j. Repeat the above steps "b", "c", and
"d".
Standard value: 2.7 MPa [at least 27.5 kgf/
cm2
(250 rpm)]
Limit: 2.2 MPa [at least 22.5 kgf/cm2 (250
rpm)]
Difference between cylinders limit: 0.5 MPa
(5.0 kgf/cm2)
OK
NG
Check and/or repair the engine.
2– 161
2– 162
6
Repair Section
Wiring Harness and Connector (EDU)
Check:
• a. Disconnect the EDU 8-pin connector
"A" (black), and the injector assembly
connector for each cylinder.
• b. Use the DST-2 to check continuity
between the EDU vehicle-side connector and the injector-side connector for
each cylinder.
Injector Driver
INJ1
INJ2
Injector Assembly
COM2
COM1
#1
#2
#3
#4
COM2
INJ3
INJ4
COM1
COM3
COM4
(Note): 8-pin connector (black) "A"
Q002709E
Malfunction Standard (Open Circuit):
5VCPFCTF
A4 (INJ1 #1)
A2 (INJ2 #2)
A1 (INJ3 #3)
A3 (INJ4 #4)
A5(COM1)
A5(COM1)
A6(COM2)
A6(COM2)
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
2 (#1)
2 (#2)
2 (#3)
2 (#4)
1 (COM1)
1 (COM4)
1 (COM2)
1 (COM3)
Q002718E
Malfunction Standard (Short Circuit)
Measurement Terminals (Terminal Names)
Injector Driver or Injector Assembly
Other Terminal and Body Ground
Standard
A4 (INJ1 #1) or 2 (#1)
Other Terminal and Body Ground
No Continuity
A2 (INJ2 #2) or 2 (#2)
Other Terminal and Body Ground
No Continuity
A1 (INJ3 #3) or 2 (#3)
Other Terminal and Body Ground
No Continuity
A3 (INJ4 #4) or 2 (#4)
Other Terminal and Body Ground
No Continuity
Q002719E
OK
Repair and/or replace the wiring harnesses
NG
Measurement Terminals (Terminal Names)
Injector Drive
Injector Assembly
or connectors.
Repair Section
7
2– 163
Coolant Temperature Sensor Check: Use a
circuit tester to measure the voltage
between the engine ECU connector terminals.
THW (+)
E2 (-)
Q002710
Standard Value:
Measurement Terminals
(Terminal Names)
A19 (THW)
Measurement
Specification
Conditions
Coolant temperature:
A28 (E2)
1.5~3.0V
0 to 30 °C (when cold)
NG
Proceed to step 9 (NE Sensor Check)
Q002720E
OK
8
Coolant Temperature Sensor Unit Check:
Use a circuit tester to measure the resistance between terminals.
Standard value: 2.0 to 2.8 kΩ (when coolant temperature is approximately 20 °C)
OK
Repair and/or replace the wiring harnesses or
connectors.
Replace the coolant temperature sensor.
NG
2– 164
9
Repair Section
NE Sensor Check: The DST-2 oscilloscope
function can be used to initiate a function
check between the engine ECU and the
NE sensor.
• a. Connect the DST-2 between engine
ECU connectors A27 (NE+) and A34
(NE-).
NE+ (+)
NE- (-)
Q002711
• b. Set the DST-2 oscilloscope function.
• c. Use the DST-2 to check the waveforms between terminals.
CH1
Ground
CH2
Ground
Q002712E
Proceed to step 11 (Rail Assembly Check)
Description
CH1: NE+
NEMeasurement Terminals
CH2: G+
GInstrument Setting
5V/DIV‫ޔ‬20ms/DIV
Measurement Conditions At start-up
Item
NG
Q002721E
OK
10
Replace the NE sensor.
NE Sensor Unit Check: Use a circuit tester
to measure the resistance between terminals.
NE-
2
1
NE+
3
Q002713
Standard value: 1.7 to 2.7 kΩ (-5 to 40 °C)
OK
Repair and/or replace the wiring harnesses or
connectors.
NG
Repair Section
11
Rail Assembly Check:
• a. Crank the engine.
• b. Use a circuit tester to measure the
voltage between the engine ECU connector terminals.
PCR1 (+)
E2 (-)
Q002714
Standard Value
Replace the engine ECU.
Measurement Terminals
Measurement
(Terminal Names)
Conditions
A26 (PCR1)
A28 (E2) When cold
NG
Specification
1.3~1.8V
Q002722E
OK
12
Replace the rail assembly.
Rail Assembly Check (Pc Sensor): Use a
circuit tester to measure the resistance
between terminals.
Standard value
Measurement Terminals (Terminal Names) 4GUKUVCPEG8CNWG
3 k‫ޓ‬or less
2 (PR)
3 (VC)
16.4 k‫ޓ‬or less
1 (E2)
2 (PR)
Q002723E
OK
NG
2– 165
2– 166
13
Repair Section
Wiring Harness and Connector Check
(Engine ECU to Pc Sensor):
• a. Disconnect engine ECU connector
"A" and the rail assembly (Pc sensor)
connector.
• b. Use a circuit tester to check for continuity and shorts between the following:
1) engine ECU vehicle-side connector
"A", and rail assembly (Pc sensor) vehicle-side connector "A"; 2) rail assembly
(Pc sensor) vehicle-side connector "A",
and the rail assembly (Pc sensor) vehicle-side connector.
Engine Control Computer
VC
PCR1
E2
Connector A
Fuel Pressure Sensor
PR
E2
VC
1 2 3
Q002715E
Standard (Open Circuit)
Repair and/or replace the wiring harnesses
Measurement Terminals (Terminal Names)
Engine ECU
Pc Sensor
#
8%
8%
#
2%4
24
#
'
'
NG
Standard
or connectors.
Continuity
Continuity
Continuity
Q002724E
Standard (Short Circuit)
Measurement Terminals (Terminal Names)
Engine ECU or Pc Sensor
Other Terminal and Body Ground
Standard
A18 (PCR1) or 2 (PR)
Other Terminal and Body Ground
No Continuity
A26 (PCR1) or 3 (VC)
Other Terminal and Body Ground
No Continuity
A28 (E2) or 1 (E2)
Other Terminal and Body Ground
No Continuity
Q002725E
OK
14
Replace
Engine ECU Replacement:
• a. Replace the engine ECU.
• b. Register the injector assembly IDs.
• c. Perform supply pump learning value
initialization.
• d. Check whether the malfunction has
been cleared.
NG
assembly.
the
injection
(supply)
pump
Repair Section
2– 167
OK
Complete
15
Glow System Check
Check and/or repair the glow system.
NG
OK
16
Replace the glow plug assembly.
Glow Plug Assembly Unit Check: Use a circuit tester to measure the resistance
NG
Q002716
Standard value: Approximately 1.0 Ω (20
°C)
OK
17
Proceed to step 19 (Intake and Exhaust
Fuel Intake System Check:
• a. Loosen the flair nut on the supply
NG
System Check)
pump high-pressure pipe.
• b. After cranking the engine, check that
fuel is discharged from the pipe.
Standard: Fuel reaches the pump
OK
18
Check for fuel system clogging (including
Check for Fuel being Delivered to the
NG
Pump
• a. Remove the supply pump inlet hose.
• b. Perform priming, and check whether
fuel reaches the pump.
Standard: Fuel reaches the pump
OK
Proceed to steps 7 (Coolant Temperature Sensor Check) through 14 (Engine ECU Replacement)
freezing), and repair.
Repair Section
2– 168
19
Check and repair malfunctioning parts.
Intake and Exhaust System Check:
• a. Check the air filter. If the filter is dirty,
NG
clean with an air gun, or replace with a
new part.
• b. Initiate the active test, to check VSV
operation, and EGR valve operation. If
the valve is normally open, block the
vacuum. Narrow down the individual
causes for the vacuum and EGR valve.
• c. Race the engine to check that the
diesel throttle is operating fully opened.
Standard: Diesel throttle is operating fully
opened.
OK
Proceed to steps 7 (Coolant Temperature Sensor Check) through 14 (Engine ECU Replacement)
20
Repair and/or replace the wiring harnesses
Starter Signal Check:
NG
• a. Crank the engine.
• b. Use the DST-2 line graph display to
check that the STA signal changes.
Standard:
While
cranking,
voltage
increases from 0V to the +B voltage.
• c. If the STA signal does not change,
use a circuit tester to measure the voltage between the engine ECU connector terminals.
Engine Control Computer
STA
Connector D
Q002717E
OK
Proceed to steps 7 (Coolant Temperature Sensor Check) through 14 (Engine ECU Replacement)
or connectors.
Repair Section
2– 169
(11) Knocking, abnormal noise
Description
Abnormal combustion occurs, and a knocking sound is generated.
Possible Cause
• Engine
• Injector
• Glow control system
• Crankshaft position sensor
Clogged air cleaner element
1
Repair the glow control system. (Refer to
the glow control system check procedure
NG
Repair the glow control system.
issued by the vehicle manufacturer.)
OK
2
Check the crankshaft position sensor.
(Refer to the crankshaft position sensor
NG
Repair or replace the crankshaft position
sensor and/or the corresponding circuit.
check procedure issued by the vehicle
manufacturer.)
OK
3
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
4
Check engine parts that may be a source
of abnormal combustion.
OK
Troubleshooting complete
NG
Repair the engine.
2– 170
Repair Section
(12) Poor fuel economy
Description
More fuel than normal is being consumed.
Possible Cause
• Engine
• Injector
• Supply pump
Clogged air cleaner element
1
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
2
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
NG
Repair or replace the supply pump and
drive circuit.
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
3
Check parts that may be a source of poor
fuel economy.
OK
Troubleshooting complete
NG
Repair the engine.
Repair Section
2– 171
(13) Black Smoke
Description
Black smoke is being exhausted.
Possible Cause
• Injector
• Supply pump
• EGR system
• Engine ECU
• Electronic control throttle
• Rail pressure sensor
• Mass Air Flow (MAF) meter
• Boost pressure sensor
Clogged air cleaner element
1
Check for air cleaner clogging and/or damage.
NG
Replace the air cleaner or repair the air
duct.
OK
2
Check the electronic control throttle and
the corresponding circuit. (Refer to the
NG
Repair or replace the electronic control
throttle and/or the corresponding circuit.
electronic control throttle check procedure
issued by the vehicle manufacturer.)
OK
3
Check the MAF meter and the corresponding circuit. (Refer to the MAF meter check
NG
Repair or replace the MAF meter and/or
the corresponding circuit.
procedure issued by the vehicle manufacturer.)
OK
4
Check the Exhaust Gas Recirculation
(EGR) system. (Refer to the EGR system
NG
Repair or replace the EGR system.
check procedure issued by the vehicle
manufacturer.)
OK
5
Check the boost pressure sensor and the
corresponding circuit. (Refer to the boost
pressure sensor check procedure issued
by the vehicle manufacturer.)
OK
NG
Repair or replace the boost pressure sensor and/or the corresponding circuit.
2– 172
6
Repair Section
Check the rail pressure sensor and the corresponding circuit. (Refer to the rail pres-
NG
Repair or replace the rail pressure sensor
and the corresponding circuit.
sure sensor check procedure issued by the
vehicle manufacturer.)
OK
7
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
8
Check the engine ECU power supply.
(Refer to the engine ECU power supply cir-
NG
Repair the engine ECU power supply.
cuit diagram issued by the vehicle manufacturer.)
OK
9
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the supply pump and
drive circuit.
Repair Section
2– 173
(14) White smoke
Description
White smoke is being exhausted.
Possible Cause
• Fuel filter
• Injector
• Supply pump
• EGR system
• Engine ECU
• Electronic control throttle
• Rail pressure sensor
Clogged air cleaner element
1
Check the fuel filter.
NG
Replace the fuel filter.
OK
2
Check each injector. (Refer to the injector
check procedure issued by the vehicle
NG
Repair or replace the injector and/or the
corresponding circuit.
manufacturer.)
OK
3
Check the Exhaust Gas Recirculation
(EGR) system. (Refer to the EGR system
NG
Repair or replace the EGR system.
check procedure issued by the vehicle
manufacturer.)
OK
4
Check the supply pump and the supply
pump drive circuit. (Refer to the supply
NG
Repair or replace the supply pump and
drive circuit.
pump drive circuit diagram issued by the
vehicle manufacturer.)
OK
5
Check the rail pressure sensor and the corresponding circuit. (Refer to the rail pressure sensor check procedure issued by the
vehicle manufacturer.)
OK
NG
Repair or replace the rail pressure sensor
and the corresponding circuit.
2– 174
6
Repair Section
Check the electronic control throttle and
the corresponding circuit. (Refer to the
electronic control throttle check procedure
issued by the vehicle manufacturer.)
OK
Troubleshooting complete
NG
Repair or replace the electronic control
throttle and/or the corresponding circuit.
Repair Section
2– 175
5.2 Other Malfunction Symptoms
Malfunctions caused by components other than the CRS
z There are cases when a particular symptom may indicate either a malfunction generated by the CRS, or a
malfunction generated by another system. For instance, engine mechanical parts and the fuel system may
cause malfunction symptoms identical to symptoms generated by the CRS. When troubleshooting, do not
assume that the source of a malfunction is the CRS. Exhaustively consider all causes while verifying the
items in the list below.
Malfunction
Symptom
Faulty Item
Intake system
Insufficient
Fuel system
Cause
Clogged air cleaner element
Action
Clean or replace the air cleaner element.
Air mixed with the fuel system
Perform fuel system air bleeding.
Faulty fuel filter
Replace the filter.
Insufficient fuel
Add fuel and perform fuel system air
bleeding.
Power
Engine
Improper fuel
Switch to the correct fuel.
Compression pressure abnormality
Refer to the engine repair manual.
Piston, cylinder liner and/or piston
ring
Other
Intake system
Overheat
Clogged air cleaner element
Clean or replace the air cleaner element.
Insufficient fuel
Add fuel and perform fuel system air
bleeding.
Faulty start-
Fuel system
Improper fuel
Replace the filter.
Fuel system clog
Clean the fuel system.
Air introduction through fuel system Tighten all connections.
connection points
ing
Fuel filter clog
Replace the fuel filter.
Loose injection piping connections
Tighten connecting nuts.
Faulty battery
Check the battery.
Electrical sys- Faulty starter wiring
Replace the starter wiring.
tem
Tighten the battery terminal connec-
Loose battery cables
tions, or replace the cables.
2– 176
Repair Section
Malfunction
Symptom
Faulty Item
Cause
Electrical sys- Faulty starter operation
Replace the starter assembly.
tem
Faulty glow plug system
Replace the glow plugs.
Lubrication
Excessive engine oil viscosity
Replace with oil of appropriate vis-
system
cosity.
Burnt pistons
Faulty starting
Action
Engine
Other
Replace the piston, piston ring and
cylinder liner.
Burnt bearings
Replace the bearing and crankshaft.
Low compression pressure
Overhaul the engine.
Ring gear damage
Replace the ring gear and/or starter
pinion gear.
Poor valve clearance
Adjust the valve clearance or replace
the bearing.
Poor valve seat contact
Faulty idling
Break in, or replace the valve and
valve seat.
Engine
Low coolant temperature
Perform warm-up operation.
Large difference in cylinder-to-cylin- Overhaul the engine.
der compression pressure
Repair Section
2– 177
6. DIAGNOSIS CODES (DTC)
6.1 DTC Chart (Example)
DTC Structure
z P####: Powertrain-related (engine, drive system)
z U####: Network-related (vehicle communication)
DTC Assignment
z PO###: Determined by SAE/ISO
z P1###: Determined by manufacturer
z P2###: Determined by manufacturer
z P3###: Mixture of items determined by SAE/ISO and items determined by the vehicle manufacturer.
DTC Chart (example for HINO and TOYOTA vehicles)
z DTC codes that apply to the CRS are listed below (compatible with the DST-2.)
DTC
DTC Description
P0006
Fuel shutoff valve "A" control circuit low voltage
P0007
Fuel shutoff valve "A" control circuit high voltage
P0016
Crankshaft position sensor, cylinder recognition sensor correlation
P0030
A/F sensor heater control circuit
P0031
A/F sensor heater control circuit low voltage
P0032
A/F sensor heater control circuit high voltage
P0036
A/F sensor heater control circuit
P0037
A/F sensor heater control circuit low voltage
P0045
Turbo/supercharger control solenoid open circuit
P0049
Turbo/supercharger overspeed
P0087
Fuel/rail pressure too low
P0088
Fuel/rail pressure too high
P0093
Fuel system leak maximum quantity detection
P0095
Intake air temperature sensor 2, circuit related
P0097
Intake air temperature sensor 2 circuit low voltage
P0098
Intake air temperature sensor 2 circuit high voltage
P0100
Mass Air Flow (MAF) meter, circuit related
P0101
MAF meter circuit range/performance
P0102
MAF meter circuit low input
P0103
MAF meter circuit high input
P0105
Boost pressure sensor, circuit related
P0107
Boost pressure sensor circuit low input
P0108
Boost pressure sensor circuit high input
Repair Section
2– 178
DTC
DTC Description
P0112
Boost pressure sensor 1 circuit low voltage
P0113
Boost pressure sensor 1 circuit high voltage
P0115
Coolant temperature sensor, circuit related
P0117
Coolant temperature sensor circuit low voltage
P0118
Coolant temperature sensor circuit high voltage
P0119
Coolant temperature sensor circuit intermittent operation
P0120
Accelerator position sensor, switch "A" circuit related
P0121
Accelerator position sensor switch "A" circuit range/performance
P0122
Accelerator position sensor switch "A" circuit low voltage
P0123
Accelerator position sensor switch "A" circuit high voltage
P0124
Accelerator position sensor switch "A" circuit intermittent operation
P0168
Fuel temperature too high
P0180
Fuel temperature sensor, "A" circuit related
P0181
Fuel temperature sensor "A" circuit range/performance
P0182
Fuel temperature sensor "A" circuit low voltage
P0183
Fuel temperature sensor "A" circuit high voltage
P0184
Fuel temperature sensor "A" circuit intermittent operation
P0185
Fuel temperature sensor, "B" circuit related
P0186
Fuel temperature sensor "B" circuit range/performance
P0187
Fuel temperature sensor "B" circuit low voltage
P0188
Fuel temperature sensor "B" circuit high voltage
P0189
Fuel temperature sensor, "B" circuit intermittent operation
P0190
Rail pressure sensor, circuit related
P0191
Rail pressure sensor circuit range/performance
P0192
Rail pressure sensor circuit low voltage
P0193
Rail pressure sensor circuit high voltage
P0194
Rail pressure sensor circuit intermittent operation
P0200
Injector open circuit
P0201
Injector open circuit- #1 cylinder
P0202
Injector open circuit- #2 cylinder
P0203
Injector open circuit- #3 cylinder
P0204
Injector open circuit- #4 cylinder
P0205
Injector open circuit- #5 cylinder
P0206
Injector open circuit- #6 cylinder
P0208
Injector open circuit- #8 cylinder
P0217
Engine overheat
P0218
Transmission overheat
P0219
Engine overrun
P0230
Fuel pump, primary circuit related
Repair Section
DTC
DTC Description
P0234
Turbo/supercharger overboost
P0237
Boost pressure sensor circuit low voltage
P0263
Cylinder correction quantity error- #1 cylinder
P0266
Cylinder correction quantity error- #2 cylinder
P0269
Cylinder correction quantity error- #3 cylinder
P0272
Cylinder correction quantity error- #4 cylinder
P0275
Cylinder correction quantity error- #5 cylinder
P0278
Cylinder correction quantity error- #6 cylinder
P0299
Turbo/supercharger supercharge deficiency
P0335
Crankshaft position sensor, "A" circuit related
P0339
Crankshaft position sensor "A" circuit intermittent operation
P0340
Cylinder recognition sensor, "A" circuit related
P0400
EGR flow volume abnormality
P0404
EGR control circuit range/performance
P0405
EGR sensor "A" circuit low voltage
P0406
EGR sensor "A" circuit high voltage
P0407
EGR sensor "B" circuit low voltage
P0408
EGR sensor "B" circuit high voltage
P0500
Vehicle speed sensor, "A" circuit related
P0501
Vehicle speed sensor "A" circuit range/performance
P0504
Brake switch "A", "B" correlation
P0510
Throttle position switch closed
P0524
Engine oil pressure too low
P0540
Intake air heater "A" circuit
P0544
Exhaust gas temperature sensor, circuit related
P0545
Exhaust gas temperature sensor circuit low voltage
P0546
Exhaust gas temperature sensor circuit high voltage
P0560
Battery voltage
P0605
Engine ECU internal malfunction
P0607
Engine ECU internal malfunction
P0611
EDU malfunction
P0617
Starter relay circuit high voltage
P0627
Fuel pump "A" open control circuit
P0686
Engine ECU power supply relay control circuit low voltage
P0704
Clutch switch input circuit abnormality
P0710
Transmission oil temperature sensor, "A" circuit related
P0715
Turbine speed sensor, "A" circuit related
P0753
Shift solenoid "A" actuation related
P0758
Shift solenoid "B" actuation related
2– 179
Repair Section
2– 180
DTC
DTC Description
P0850
Parking/neutral switch, input circuit related
P2002
Particulate Matter (PM) capture efficiency at or below specified value
P2031
Exhaust gas temperature sensor, circuit related
P2032
Exhaust gas temperature sensor circuit low voltage
P2033
Exhaust gas temperature sensor circuit high voltage
P2047
Exhaust gas fuel addition valve abnormality
P2120
Accelerator position sensor, switch "D" circuit related
P2121
Accelerator position sensor switch "D" circuit range/performance
P2122
Accelerator position sensor, switch "D" circuit low input
P2123
Accelerator position sensor, switch "D" circuit high input
P2125
Accelerator position sensor, switch "E" circuit related
P2127
Accelerator position sensor, switch "E" circuit low input
P2128
Accelerator position sensor, switch "E" circuit high input
P2138
Accelerator position sensor, switch "D"/"E" circuit voltage correlation
P2226
Atmospheric pressure sensor, circuit related
P2228
Atmospheric pressure sensor circuit low voltage
P2229
Atmospheric pressure sensor circuit high voltage
Volkswagen Technical Site: http://vwts.ru http://volkswagen.msk.ru http://vwts.info
огромный архив документации по автомобилям Volkswagen, Skoda, Seat, Audi
Published
: September 2007
Revised
: July 2008
Editing/Issuing Department :
DENSO CORPORATION
Service Department
1-1 Showa-cho, Kariya, Aichi Prefecture, Japan
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