DENSO E-03-03 Diesel Injection Pump, J08C, J05C Common Rail System SERVICE MANUAL

Below you will find brief information for Diesel Injection Pump E-03-03, Common Rail System J08C, Common Rail System J05C. This manual outlines the operation and components of the common rail system for HINO J08C/J05C type engines. The system features high pressure fuel injection for lower exhaust gas emissions and higher output. The manual includes details on the fuel system, the control system, and the construction and operation of key components such as the supply pump, rail, injectors, sensors, and relays. It also covers various control functions such as fuel injection rate control, injection quantity control, injection timing control, and injection pressure control.

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For DENSO Authorized

ECD Service Dealer Only

Diesel Injection Pump

No. E-03-03

SERVICE MANUAL

Common Rail System for HINO

J08C/J05C Type Engine

Operation

June, 2003

-1

00400024

GENERAL

The ECD-U2 was designed for electronic control of injection quantity, injection timing and injection pressure to obtain optimal operational control.

Features

• Lower exhaust gas and higher output due to high pressure injection in all usage ranges.

• Reduction in noise and exhaust gas due to injection rate control.

• Improved performance due to increased flexibility in the injection timing setting.

• Independent control of injection pressure in response to engine speed and load.

Main Elements

Manufacturer

Hino Motor, Ltd.

Vehicle

Model

HR1J

RX4JFE

Engine

Model

J08C

J05C

Cylinder

Configuration

Straight 6

Straight 4

Total

Displacement

(cc)

Maximum Output

(PS/rpm)

7,961

5,307

J-N: 205/2,900

J-V: 220/2,900

175/2,900

Main Components Part Number

No.

Description

HR1J (J08C-UC)

DENSO P/N HINO P/N

RX4JFE (J05C-TG)

DENSO P/N HINO P/N

094000-0183 22730-1042A 094000-0193 22730-1072A 1 Supply pump

1-1

Cylinder recognition sensor

029600-0580 89411-1290A1 029600-0580 89411-1290A1

2 Injector

3 Rail

095000-0174 23910-10033C 095000-0174 23910-10033C

095440-0243 22760-1100C 095440-0171 22760-1041C

3-1 Rail pressure sensor 499000-4441

3-2 Pressure limiter 095420-0060

3-3 Flow damper 095400-0150

—

499000-4441

095420-0060

095400-0150

—

1. Outline

1.1 System Outline

This system also provides the following functions:

• A self-diagnosis and alarm function using computer to diagnose the system’s major components and alert the driver in the event of a problem.

• A fail-safe function to stop the engine, depending upon the location of the problem.

• A backup function to change the fuel regulation method, thus enabling the vehicle to continue operation.

1.2 System Configuration

Divided by function, the system can be classified according to the fuel system and the control system.

[1] Fuel System

High-pressure fuel that is generated by the supply pump is distributed to the cylinders using a rail.

Electromagnetic valves in the injectors then open and close the nozzle needle valve to control the start and end of fuel injection.

Electronic control

Solenoid valve to control the needle lift

Fuel tank Supply pump

Discharge volume

Rail Injector

Q000080E

[2] Control System

Based on the signals received from various sensors mounted on the engine and the vehicle, the

ECU controls current timing and the duration in which the current is applied to the injectors, thus ensuring an optimal amount of fuel is injected at an optimal time.

The control system can be broadly classified according to the following electronic components: sensors, computers, and actuators.

Sensors

Accelerator sensor

NE sensor

(Crankshaft position sensor)

TDC sensor

(Cylinder recognition sensor)

Other sensors and switches

(Accelerator opening)

Computers

(Engine speed)

(

Cylinder recognition signal

)

ECU

Actuators

Injectors

( Fuel injection quantity and injection timing control etc.

)

Rail

Supply pump

(Fuel pressure control)

Q000081E

[3] System Configuration (1)

Signals from switches

ECU

Charge-up circuit

ACCP,

ACCSW

Accelerator position sensor

STA

THW

Starter signal

Air cleaner

THL

Fuel temp.

sensor

Leak pipe

Rail

Pressure limiter

Flow damper

Supply pump

Water temp. sensor

NE sensor

Fuel filiter

TDC sensor

Fuel tank

Q000089E

[4] System Configuration (2)

Q000115E

1.3 Construction and Operation of the System

The rail system is comprised of a supply pump, a rail, and injectors, and also includes an ECU and sensors to regulate those components.

The supply pump generates the internal fuel pressure in the rail. Fuel pressure is regulated by the quantity of fuel discharged by the supply pump. In turn, the fuel discharge quantity is regulated by electronic signals from the ECU that turn the PCVs (pump control valves) ON and OFF.

Upon receiving fuel pressurized by the supply pump, the rail distributes the fuel to the cylinders.

The pressurized fuel is detected by the rail pressure sensor (installed in the rail) and undergoes feedback control so that actual pressure will match the command pressure (designated according to the engine speed and load).

Pressurized fuel in the rail passes through the injection pipes that lead to the cylinders, and applies pressure to the injector nozzles and the control chamber.

The injector regulates injection quantity and timing by turning the TWV (two-way valve) ON and OFF.

When the TWV is ON (current applied), the fuel circuit switches over, causing the high-pressure fuel in the control chamber to flow out via the orifice. As a result, the force of the high-pressure fuel at the nozzle valve opening causes the needle valve to lift, thus starting the injection of fuel.

When the TWV is turned OFF (current not applied), the fuel circuit switches over so that highpressure fuel, traveling via the orifice, is introduced to the control chamber. As a result, the needle valve lowers, thus ending the injection of fuel.

Thus, through electronic control, the timing of the current applied to the TWV determines the injection timing, and the duration in which current is applied to the TWV determines the injection quantity.

Additional information

(temperature, pressure)

Engine load

ECU

TWV control pulse

Rail pressure sensor

Rail

TWV

· Injection volume control

· Injection timing control

· Injection rate control

Leak

Orifice

Injection pressure control

Control chamber

Hydraulic piston

Supply Pump

Injector

Nozzle

Needle

Q000084E

1.4 Comparison to Conventional Pump

Inline Type Common Rail System

System

Timer

Pipe

Instantaneous high pressure

Governor

Pump

Nozzle

Rail

Supply pump

Constant high pressure

Injector

Injection quantity regulation

Injection timing regulation

Distribution of generated pressure

Pump (governor)

Pump (timer)

Pump

Distribution

Pump

Injection pressure regulation

(Dependent on engine speed and injection volume)

ECU, injector (TWV)

Supply pump

Rail

Supply pump (PCV)

Q000085E

2. Construction and Operation of Components

2.1 Supply Pump

[1] Outline

The function of the supply pump is to regulate the fuel discharge volume, thus generating internal fuel pressure in the rail.

[2] Construction

The supply pump consists of a feed pump, similar to that of the conventional in-line pump, and the PCVs (pump control valves), provided at each cylinder, to regulate the fuel discharge volume.

The supply pump uses a three-lobe cam or two-lobe cam reducing the number of pump cylinders to one-third or one-second of the engine cylinders (e.g. a two-cylinder pump for a six-cylinder engine or for a four-cylinder engine). Furthermore, a smooth and stable rail pressure is obtained because the rate at which fuel is pumped to the rail is the same as the injection rate.

PCV (Pump Control Valve) for J08C for J05C

Feed pump

Gear of cuxiliary

NE sensor

3-lobe cam

2-lobe cam

Q000116E

[3] Operation

A: The PCV remains open during the plunger’s downward stroke, allowing low-pressure fuel to be drawn into the plunger chamber by way of the PCV.

B: If the valve remains open because current is not applied to the PCV, even after the plunger begins its upward stroke, the fuel that was drawn in returns via the PCV, without being pressurized.

C: When current is applied to the PCV in order to close the valve at the timing that accommodates the required discharge volume, the return passage closes, causing pressure in the plunger chamber to rise. The fuel then passes through the delivery valve (check valve) to the rail. As a result, an amount of fuel that corresponding to the plunger lift after the PCV closes becomes the discharge volume, and varying the timing of the PCV closure (plunger prestroke) varies the discharge volume, thus regulating rail pressure.

A’: After surpassing the maximum cam lift, the plunger begins its downward stroke, causing pressure in the plunger chamber to decrease. At this time, the delivery valve closes, thus stopping the pumping of the fuel. In addition, because current to the PCV valve is cut off, the

PCV opens, allowing low-pressure fuel to be drawn into the plunger chamber. Thus, the pump assumes condition “A”.

Suction process Delivery process

Cam lift

PCV operation

Pump operation

Valve closed

Valve open

PCV

Pre-stroke

Increasing dischargevolume

Reducing discharge volume

Discharge volume Q=

π d

(H-h)

Discharging required dischrge volume

Common rail h

Plunger

Delivery valve

φ d

A B C A'

Q000087E

[4] PCV (pump control valve)

The PCV regulates the volume of fuel discharged by the supply pump in order to regulate rail pressure. The volume of fuel discharged by the supply pump to the rail is determined by the time at which current is applied to the PCV.

PCV relay

Key switch

ECU

PCV1

PCV2

PCV

Q000088E

[5] Trochoid Type Feed Pump

The feed pump, which is housed in the supply pump, draws fuel up from the tank and delivers it to the chamber via the fuel filter. The feed pump rotor is driven by the camshaft.

The rotation of the camshaft causes the outer and inner rotors to rotate. At this time, the suction port side pump chamber volume (the space surrounded by the outer and inner rotors) increases gradually, causing the fuel entering from the fuel inlet to be drawn into the pump chamber via the suction port. Along with the rotation of the rotor, the fuel that has been drawn in moves towards the discharge port and is discharged. The discharged fuel travels via the fuel outlet and is fed into the supply pump body.

Outer rotor

To pump chamber

Volume decreased

(while moving to discharge port)

Volume decreased

(while discharging fuel to discharge port)

Inner rotor

Suction port

From fuel tank

Discharge port

Volume increased

(while drawing in fiel)

[6] Coupling

The coupling is an intermediary device that transmits the engine driving torque to the supply pump camshaft.

Volume increased

(while drawing in fiel)

Q000090E

Coupling

Q000091E

2.2 Rail

[1] Construction

The functionof the rail is to distribute the high-pressure fuel pressurized by the supply pump to each cylinder injector.

The rail pressure sensor, flow damper, and pressure limiter are mounted on the rail.

A fuel injection pipe is attached to the flow damper to deliver high-pressure fuel to the injector.

The pressure limiter piping is routed back to the fuel tank.

for J08C for J05C

Flow damper

Pail pressure sensor

Pressure limiter

Rail

[2] Flow Damper

The flow damper reduces pressure pulsation in the high-pressure pipe, thus delivering fuel to the injectors at a stable pressure. Furthermore, in the event an excessive flow of fuel, the flow damper shuts off the fuel passage, thus preventing the abnormal fuel flow.

When abnormal amount of fuel flows the high-pressure is applied to the piston. As shown in the illustration, this causes the piston and ball to move right, until the ball reaches the seat and closes the fuel passage.

Stopped

During damping

During abnormal flow such as excessive injection volume

Pail pressure sensor

Q000117E

Piston

Ball

Seat

Q000093E

[3] Pressure Limiter

The function of the pressure limiter is to dispel abnormally high pressure by opening its valve to release pressure.

The pressure limiter operates (opens the valve) when rail pressure reaches approximately 140MPa.

Then, when the pressure decreases to approximately

30MPa, the pressure limiter resumes (closes the valve) its function to maintain pressure.

Q000094E

NOTE:

Do not attempt to remove or to reinstall the flow damper, pressure limiter, and the rail pressure sensor.

[4] Rail Pressure Sensor

The rail, the rail pressure sensor is mounted on the rail and detects the fuel pressure. It is a semi-conductor type of pressure sensor that utilizes the properties of silicon to change its electrical resistance when pressure is applied.

A-VCC

VPC

A-GND

ECU

+5V

VPC

0 50 100

Pressure PC (MPa)

150

Q000095E

2.3 Injector

[1] Outline

The function of the injector is to inject high-pressure fuel from the rail into the engine combustion chamber at the proper timing, quantity, ratio, and atomization, in accordance with signals from the ECU.

The TWV (two-way solenoid valve) regulates pressure in the control chamber in order to control the beginning and end of injection.

The orifice restrains the opening speed of the nozzle valve to regulate the injection ratio.

The command piston transmits pressure from the control chamber to the nozzle needle valve.

The nozzle atomizes the fuel.

ECU

Start of Injection (TWV ON)

TWV

Rail pressure sensor

Rail

Leak

ECU

End of Injection (TWV OFF)

TWV

Rail pressure sensor

Rail

Leak

Supply pump

Injection pressure control

Orifice

Control chamber

Command piston

Supply pump

Injection pressure control

Nozzle

Orifice

Control chamber

Command piston

Nozzle

Q000096E

[2] Construction

The injector consists of the nozzle portion (similar to that of the conventional type), the orifice

(which regulates the injection ratio), the command piston, and the two-way solenoid valve

(TWV).

Plastic cover

Linkage joint bolt

Gasket

Outlet connector

Filter

Steel washer

Inlet connector

Upper body

O-ring

TWV

Control chamber

Orifice 2

Orifice 1

Command piston

Lower body

Nozzle spring

Pressure pin

Guide bushing

Valve opening pressure adjustment shim

Tip packing

Nozzle

Retaining nut

Q000118E

[3] Operation

The TWV portion of the injector consists of two valves, an inner valve (fixed) and an outer valve

(movable). Both valves are precision-fitted on the same axis. The valves respectively form inner and outer seats, and either of the seats opens selectively depending upon whether the TWV is

ON or OFF.

a. No Injection

When no current is applied to the solenoid, the valve spring and hydraulic pressure forces push the outer valve downward, causing the outer seat to remain closed. Because the rail high pressure is applied to the control chamber via the orifices, the nozzle remains closed without injecting fuel.

b. Begin Injection

When current is applied to the TWV, the solenoid force pulls the outer valve upward, causing the outer seat to open.

As a result, fuel from the control chamber flows out via the orifice, causing the needle to lift and fuel to start injection. Furthermore, the injection ratio increases gradually in accordance with the movement of the orifice. As the application of current continues to apply, the injector reaches its maximum injection ratio.

c. End Injection

When current to the TWV is cut off, the valve spring and hydraulic force (fuel pressure) cause the outer valve to descend and the outer seat closes. At this time, high-pressure fuel from the rail is immediately introduced into the control chamber, causing the nozzle to close suddenly.

As a result, injection ends swiftly.

Inner valve

Outer valve

Outer seat

Orifice 2

Orifice 1

Rail

(constant high pressure)

25-120 MPa

Command piston

Control chamber

Nozzle

No Injection Begin Injection End Injection

Q000098E

[4] Circuit Diagram for J08C

COMMON2

COMMON1

ECU

TWV #1

(No. 1 cylinder)

TWV #2

(No. 4 cylinder)

TWV #3

(No. 2 cylinder)

TWV #4

(No. 6 cylinder)

TWV #5

(No. 3 cylinder)

TWV #6

(No. 5 cylinder)

Constant current circuit

Charging circuit

Q000119E

for J05C

COMMON2

COMMON1

ECU

TWV #1

(No. 1 cylinder)

TWV #2

(No. 4 cylinder)

TWV #3

(No. 3 cylinder)

TWV #4

(No. 2 cylinder)

Constant current circuit

Charging circuit

Q000120E

WARNING:

High voltage is applied to the wires connected to COMMON1, COMMON2, and the TWV

#1-#6 terminals of the ECU. Exercise extreme caution to prevent electric shock.

2.4 Sensors and Relays

[1] NE Sensor (crankshaft position sensor)

When the signal holes on the flywheel move past the sensor, the magnetic line of force passing through the coil changes, generating alternating voltage.

The signal holes are located on the flywheel at 7.5-degree intervals. There are a total of 45 holes, with holes missing in three places. Therefore, every two revolutions of the engine outputs 90 pulses.

This signal is used to detect the engine speed and the crankshaft position in 7.5-degree intervals.

[2] TDC sensor (cylinder recognition sensor)

Similar to the NE sensor, the sensor utilizes the alternating voltage generated by the changes in the magnetic line of force passing through the coil.

The disc-shaped gear located in the center of the supply pump camshaft has a cog (U-shaped cutout) at 120-degree intervals, plus one tooth in an additional location. Accordingly, every two revolutions of the engine outputs seven pulses. The combination of the NE pulse, auxiliary pulse is recognized as the No. 1 cylinder reference pulse.

NE (crankshaft angle) sensor

TDC (cylinder recognition) sensor

A combination of the NE pulse and the TDC pulses are used for the cylinder reference pulse, and the irregular pulse is used to determine the No. 1 cylinder.

for J08C

TDC

ECU

Q000100E

Q000121E

Input circuit

for J05C

TDC

Q000122E

ECU

Input circuit

Q000123E

for J08C

No.6 cylinder TDC reference pulse

No.1 cylinder TDC reference pulse

No.1 cylinder recognition pulse

0°CR 120°CR 240°CR 360°CR 480°CR 600°CR 720°CR

#1 TDC #4 TDC #2 TDC #6 TDC #3 TDC #5 TDC #1 TDC

TDC pulse

75°CR 75°CR 75°CR 75°CR 75°CR 75°CR 75°CR

105°CR

NE pulse

0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 0 2 4 6 8

No.1 cylinder NE reference pulse

No.6 cylinder NE reference pulse

Q000124E

for J05C

No.4 cylinder TDC reference pulse No.1 cylinder TDC reference pulse

No.1 cylinder recognition pulse

0°CR 180°CR 360°CR 540°CR 720°CR

#1 TDC #4 TDC #3 TDC #2 TDC #1 TDC

TDC pulse

135°CR 135°CR 135°CR 135°CR

165°CR

NE pulse

0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 0 2 4 6 8

No.1 cylinder NE reference pulse

No.4 cylinder NE reference pulse

Q000125E

[3] Water Temperature Sensor (THW made another manufacturer)

The water temperature sensor detects the temperature of the engine coolant water and outputs it to the ECU.

The sensor uses a thermistor, which varies resistance according to temperature. As the ECU applies voltage to the thermistor, it uses a voltage resulting from the division of the computer internal resistance and the thermistor resistance to detect the temperature.

Q000104E

VTHW

ECU

+5V

VTHW

A-GND

0 -40 -20 0 20 40 60 80 100 120 THW

Coolant temperature (°C)

Q000105E

[4] Fuel Temperature Sensor (THL)

The fuel temperature sensor detects the fuel temperature and outputs it to the ECU. The sensor uses a thermistor, which varies resistance according to temperature. As the ECU applies voltage to the thermistor, it uses a voltage resulting from the division of the computer internal resistance and the thermistor resistance to detect the temperature.

VTHL

A-GND

ECU

+5V

VTHL

0 -40 -20 0 20 40 60 80 100 120 THL

Fuel temperature (°C)

Q000106E

[5] Atmospheric Air Presuure Sensor (Built-in ECU)

This sensor converts the atmospheric air pressure into an electrical signal to correct full-load injection volume.

VPATM

4.00

101

Atmospheric air pressure (kPa)

Q000126E

[6] Accelerator Position Sensor

This sensor converts the angle of the pedal effort applied to the accelerator pedal into electrical signals and sends them to the ECU. The accelerator sensor uses hall elements. A magnet is mounted on the shaft that moves in unison with the accelerator pedal, and the magnetic field orientation changes with the rotation of the shaft. The changes in the magnetic field orientation generate voltage.

ECU

Hall elements

(2 pieces)

Magnets

(1 pair)

A-Vcc

VACCP1

A-GND

A-Vcc

VACCP2

A-GND

+5V

4.0

VAccp1

VAccp2

(V)

3.0

2.0

1.0

50 100

Accelerator opening (%)

Accp

Q000107

[7] Boost Pressure Sensor

In order to correct the full-load injection volume, this sensor converts the intake air pressure

(absolute pressure) into an electrical signal, then amplifies it into a voltage signal to the computer.

A-VCC

ECU

+5V

VPIM

4.0

VPIM

Output valtage

(V)

2.0

A-GND

100 200 300

Intake air pressure PIM (kPa)

Q000141E

[8] Idle Set Button (made by another manufacturer)

A control knob is provided within the driver’s reach, enabling the driver to set the idle speed.

A-VCC

V-IMC

A-GND

ECU

+5V

Q000142E

[9] Main Relay

To supply current to the ECU, the main relay points close when current is applied the main relay coil.

[10] PCV Relay

It is a relay that supplies current to the supply pump’s PCV (discharge volume control valve).

3. Various Types of Control

This system controls the fuel injection quantity and injection timing more optimally than the mechanical governor or timer used in conventional injection pumps.

For system control, the ECU makes the necessary calculations based on signals received from sensors located in the engine and on the vehicle in order to control the timing and duration in which current is applied to the injectors, thus realizing optimal injection timing.

[1] Fuel Injection Rate Control Function

The fuel injection rate control function controls the ratio of the quantity of fuel that is injected through the nozzle hole during a specified period.

[2] Fuel Injection Quantity Control Function

The fuel injection quantity control function, replaces the conventional governor function, and controls fuel injection to achieve an optimal injection quantity based on the engine speed and the accelerator opening.

[3] Fuel Injection Timing Control Function

The fuel injection timing control function, replaces the conventional timer function, and controls the fuel injection to achieve an optimal injection timing according to the engine speed and the injection quantity.

[4] Fuel Injection Pressure Control Function (Rail Pressure Control Function)

The fuel injection pressure control function (rail pressure control function) uses a rail pressure sensor to measure fuel pressure, and feeds this data to the ECU to control the pump discharge quantity.

Pressure feedback control is implemented to match the optimal quantity (command quantity) set according to the engine speed and the fuel injection quantity.

Control output

Input signal

Accelerator sensor

Fuel injection rate control

NE sensor

(Crankshaft position sensor)

Fuel injection quantity control

TDC sensor

(Cylinder recognition sensor)

Fuel control computer

(ECU)

Fuel injection timing control

Rail pressure sensor

Various sensors

·Water temperature sensor

·Fuel temperature sensor

·Atmospheric air temperature

sensor etc.

Atmospheric air pressure sensor

Fuel injection pressure control

Diagnosis

Q000109E

3.1 Fuel Injection Rate Control

[1] Main Injection

Same as conventional fuel injection.

[2] Pilot Injection

Pilot injection is the injection of a small amount of fuel prior to the main injection.

Pilot injection

Main injection

While the adoption of higher pressure fuel injection is associated with an increase in the injection rate, the lag (injection lag) that occurs from the time fuel is injected until combustion starts cannot be reduced be-

Q000110 low a certain value. As a result, the quantity of fuel injected before ignition increases, resulting in explosive combustion together with ignition, and an increase in the amount of NOx and noise. Therefore, by providing a pilot injection, the initial injection rate is kept to the minimum required level dampening, the explosive first-period combustion and reducing NOx emissions.

TDC

Combustion process

Delta injection

Small injection amount prior to ignition

High injection rate

Improvement

Pilot injection

Injection rate

Large pre-mixture combustion

(NOx, noise)

Heat generation rate

Ignition delay

[3] Split Injection

When the rotation is low at starting time, a small amount of fuel is injected several times prior to main injection.

Small pre-mixture combustion

Q000111

Split injection

Q000112

3.2 Fuel Injection Quantity Control

[1] Starting Injection Quantity

The injection quantity is determined based on the engine speed (NE) and water temperature while starting, with the accelerator pressed 50% or more.

Water temperature

[2] Transient Injection Quantity Correction

When the changes in the accelerator opening are great during acceleration, the increase in fuel volume is delayed to inhibit the discharge of black smoke.

Engine speed

Q000127E

Change in accelerator opening

Injection quantity after correction

Delay time

Time

Q000128E

[3] Basic Injection Quantity

This quantity is determined in accordance with the engine speed (NE) and the accelerator opening.

Increasing the accelerator opening while the engine speed remains constant causes the injection quantity to increase.

Accelerator opening

Engine speed

Q000129E

[4] Injection Quantity for Maximum Speed Setting

The injection quantity is regulated by a value that is determined in accordance with the engine speed.

Engine speed

Q000130E

[5] Maximum Injection Quantity

This quantity is calculated by adding the amount of Qadjustment resistor correction and the amount of injection quantity fuel temperature correction to the basic maximum injection quantity that has been determined in accordance with the engine speed.

Engine speed

Q000131E

[6] Amount of Q-Adjustment Correction

Selects the one of eight values determined by data in

ROM built in ECU.

Characteristic curve is fixed by the value.

Basic maximum injection quantity

8 patterns in this range.

Engine speed

Q000132E

[7] Amount of Injection Quantity Intake Pressure

Correction

Limits the maximum injection quantity in accordance with the intake pressure, in order to minimize the discharge of smoke when the intake air pressure is low.

Engine speed

Q000133E

[8] Amount of Injection Quantity by Atmospheric

Air Pressure Correction

With using atmospheric air pressure sensor signal, the maximum injection quantity curve is corrected as shown in the right figure.

Engine speed

Q000134E

[9] Idle Speed Control System (ISC)

Controls the idle speed by regulating the injection quantity in order to match the target speed, which has been calculated by the computer, with the actual speed. The functions of the ISC can be broadly divided into the following two items:

• Auto ISC

Controls the idle speed in accordance with the water temperature.

• Manual ISC

Controls the idle speed in accordance with the idle speed indicated on the manual idle setting knob provided at the driver’s seat.

Water temperature

Q000135E

ISC knob terminal voltage

Q000136E

• Aircon Idle-up Control

When the conditions shown in the chart on the right are realized, bring the idle-up speed to 735 rpm.

Conditions

Air conditioning SW = "ON"

Clutch SW = "ON"

(clutch connection)

Neutral SW = "ON" (neutral)

Q000137E

[10] Auto Cruise Control

Controls the actual vehicle speed by regulating the injection quantity in order to match the target speed that has been calculated by the computer with the actual speed.

3.3 Fuel Injection Timing Control

The characteristics of the fuel injection timing vary depending on whether it is the main injection or the pilot injection. Although either the NE sensor or the auxiliary NE sensor is the reference for controlling the injection timing, the NE sensor is ordinarily used for this purpose.

[1] Main Injection Timing

The basic injection timing is calculated in accordance with the final injection quantity, the engine speed, and the water temperature (with map correction).

While starting, it is calculated in accordance with the water temperature and the engine speed.

Final injection quantity

Engine speed

Q000138E

[2] Pilot Injection timing (Pilot Interval)

The pilot injection timing is controlled by adding the pilot interval to the main injection timing.

The pilot interval is calculated in accordance with the final injection quantity, the engine speed, and the water temperature (with map correction).

While starting, it is calculated in accordance with the water temperature and the engine speed.

[3] Fuel Injection Pressure Control

(1) Fuel Injection Pressure

A value is calculated as determined in accordance with the final injection quantity and the engine speed.

While starting, it is calculated in accordance with the water temperature and the engine speed.

Final injection quantity

Engine speed

Q000139E

Final injection quantity

Engine speed

Q000140E

4. Diagnostic Trouble Codes

No.

Exhaust brake light

–

1&2

Meaning of the diagnostic trouble code (DTC) or the diagnosis item

Normal

NE sensor system abnormal

TDC sensor system abnormal

Both NE and TDC sensors abnormal

4 1 Coolant temperature sensor abnormal

1&2

1&3

2&4

Fuel temperature sensor abnormal

Starter switch system abnormal

Engine stop switch system abnormal

Intake air pressure sensor system abnormal

Accelerator position sensor 1 voltage abnormal

Accelerator position sensor 2 voltage abnormal

Both accelerator position sensors voltage abnormal

Accelerator position sensor 1 or 2 fixed voltage abnormal

Idle set button abnormal

Vehicle speed sensor system abnormal

FSV solenoid valve system abnormal

CBCS1 solenoid valve system abnormal

CBCS2 solenoid valve system abnormal

Exhaust brake solenoid valve system abnormal

Engine retarder relay system abnormal

Transmission retarder system abnormal

Accelerator linked relay system abnormal

PCV1 +B short

PCV1 GND short

PCV2 +B short

PCV2 GND short

PCV1 & 2 both +B shortf1

PCV1 & 2 both GND shortf1

PCV relay system abnormal

Rail pressure abnormal (sensor system)

Rail pressure abnormal (output fixed)

Rail pressure abnormal (excessive pumping by pump)

Rail pressure abnormal (control system)

Estimated cause of the malfunction

—

Wiring harness open circuit, short, or defective sensor

Switch seized or wiring harness short

Wiring harness open circuit, short, or defective sensor

Wiring harness short

Wiring harness open circuit, short, or defective sensor

Wiring harness open circuit, short, or defective solenoid valve

When an improper ECU is installed on the vehicle

Wiring harness open circuit, short, or defective solenoid valve / relay

Wiring harness open circuit, short, or defective relay

Wiring harness open circuit, short, or defective sensor

Warning light [mode]

—

Light ON [2]

Blinking

—

Light ON [2]

Blinking

Light ON [2]

—

Light ON [2]

—

Light ON [1]

Blinking

Light ON [1]

—

Yes*

—

Multiplex indication

—

Yes*

—

Fuel injection

Contents of fail-safe action

Exhaust brake engine retarder

—

Cruise control

— —

Control by TDC sensor

Control by NE sensor

Engine stopped

Control continued as 80 °C during normal operation and as -20 °C during starting

Control continued according to the coolant temperature sensor data

Normal control

Stopped

Normal control

Stopped

Normal control

Switch input invalidated

Control continued as intake air pressure of 100kPa

Control continued using accelerator position sensor 2

Control continued using accelerator position sensor 1

Backup with idle set button

Control continued with the normal accelerator position sensor

Fixed to voltage of 0.2V when setting manually

Normal control

Stopped

Normal control

Normal control Normal control Stopped

Tachometer

—

Normal control

Stopped

Normal control

Limit injection quantity

Normal control

Limit injection quantity

Stopped

Normal control

Limit injection quantity

Normal control

Stopped

Normal control

Stopped

Normal control

* The multiplex display screen indicates “Engine”.

No.

Exhaust brake light

Meaning of the diagnostic trouble code (DTC) or the diagnosis item

Flow damper activated (No. 1 cylinder)

Flow damper activated (No. 2 cylinder)

Flow damper activated (No. 3 cylinder)

Flow damper activated (No. 4 cylinder)

Flow damper activated (No. 5 cylinder) - For J08C only

Flow damper activated (No. 6 cylinder) - For J08C only