wiring ISUZU TF SERIES 2004 Repair Manual

ELECTRICAL-BODY AND CHASSIS 8A-121
2. High or low beam does not light on both headlights

Checkpoint Trouble Cause Countermeasure


Repair or replace the
combination switch

Dimmer
passing switch
continuity

Poor switch contact or switch
faulty
NG

Repair open circuit or
connector contact
Voltage between
4
X-4 - ground and
4
B-60 - ground

Open circuit between
headlight and dimmer
passing
switch
NG OK



3. RH (or LH) high and low beam does not light



Replace the headlight bulb

Headlight connector continuity

Blown filament or air leakage
NG

Repair or replace the wire
and/or connector
Wiring continuity between
connector 3
C-19 - fuse No.
EB-7 or 3
C-26 fuse No.
EB-8

Open circuit and/or poor
connector contact
NG OK

Reinstall or replace fuse No.
EB-7 or No. EB-8
Fuse No. EB-7 (10A) or
No. EB-8 (10A) (Relay and
fuse box)
(No. EB-7 RH, No. EB-8: LH)
Poor installation or blown fuse
NG
OK



4. High or low beam does not light on one headlight (RH or LH)

Replace the headlight
assemblyHeadlight connector continuityBlown filament NG
Repair open circuit or
connector contactWiring continuity between
headlight and dimmer
passing
switchOpen circuit between
headlight and dimmer
passing
switch NG OK

8A-122 ELECTRICAL-BODY AND CHASSIS
5. Headlight does not go out

Checkpoint Trouble Cause Countermeasure


Replace the lighting relay
Lighting relay continuity
between connector 1
X-12
- 2
X-12 (Should be no
continuity)

Relay point fused
NG

Replay the combination switch
Lighting switch continuity
between connector 3
B-60
-1
B-60 when switch is
OFF(Should be no continuity)

point fused or faulty

NG
OK OK

Repair or replace the
combination switch
Dimmer
passing switch con-
tinuity between connector
3
B-60 - 1 B-60 when switch
is not operating
(Should be no continuity)

Switch point fused or faulty
NG
Repair short circuit
between 4
X-12 - 3 B-60
and 4
X-1 - 2 B-60
Check if headlight goes out
when connector
C-30 is
disconnected


Short circuit
NG OK



6. Insufficient headlight brightness



Replace the headlight bulb

Headlight bulb

Bulb filament faulty
NG

Repair the wiring
Dimmer
passing switch
Wire continuity between con-
nector 1
B-60 - C-36


Poor ground point contact
NG OK

Clean the light lens

Headlight lens

Lens dirty
NG
OK

ELECTRICAL-BODY AND CHASSIS 8A-131


LICENSE PLATE LIGHT
Removal
1. Remove the lens cover 1 and the connector 2.
2. Pull the bulb
3 to remove it.



Installation
Follow the removal procedure in the reverse order to install the
license plate light.
Pay close attention to the important points mentioned in the
following paragraphs.



Bulb
Be absolutely sure that the license plate light bulb is correctly
installed.
This will prevent a poor contact and open circuit.



HEADLIGHT BEAM SWITCH
(COMBINATION SWITCH)
Removal
1. Disconnect the battery ground cable.
2. Remove the screws on the lower part of the steering wheel.
3. Remove the horn pad.
4. Remove the wiring connector.
5. Remove the steering wheel fixing nuts.
6. Remove the steering wheel.
Refer to the "STEERING" Section of this manual.
7. Remove the Instrument panel lower cover.
8. Remove the steering column cover.
9. Disconnect the connector.
10. Remove the headlight beam switch (lever) from the steering
shaft (combination switch).


Installation
Follow the removal procedure in the reverse order to install the
headlight beam switch (lever).
Pay close attention to the important points mentioned in the
following paragraphs.



Connector
Be absolutely sure that the headlight beam switch connector is
securely connected.
This will prevent a poor contact and an open circuit.

8A-192 ELECTRICAL-BODY AND CHASSIS
REMOVAL AND INSTALLATION









DOME LIGHT
Removal
1. Remove the dome light lens 1 free.
2. Remove two dome light fixing screws.
3. Remove the wiring connector.
4. Remove the dome light.
5. Pull the bulb
2 to remove it.







Installation
Follow the removal procedure in the reverse order to install the
dome light.
Pay close attention to the important points mentioned in the
following paragraphs.



Bulb
Be absolutely sure that the dome light bulb is correctly
installed.
This will prevent a poor contact and an open circuit.

CRUISE CONTROL SYSTEM 8B-3
Service Precaution
WARNING: THIS VEHICLE HAS A SUPPLEMENTAL RESTRAIN SYSTEM (SRS). REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS COMPONENTS OR THE SRS WIRING. WHEN YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS COMPONENTS OR THE SRS WIRING, REFER TO THE SRS
SERVICE INFORMATION. FAILURE TO FOLLOW WARNINGS COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR OTHER WISE UNNEEDED SRS SYSTEM REPAIRS.

CAUTION: Always use the correct fastener in the proper location. When you replace a faster, use ONLY the
exact part number for that application. Dealer will call out those fasteners that require a replacement after
removal. Dealer will also call out the fasteners that require thread lockers or thread sealant. UNLESS
OTHERWISE SPECIFIED, do not use supplemental coatings (Paints, greases, or other corrosion inhibitors)
on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener
torque and joint Clamping force, and may damaged the fastener. When you install fasteners, use the
correct tightening sequence and specifications. Following these instructions can help you avoid damage to
parts and systems.

General Description
The cruise control keeps the vehicle running at a fixed speed until a signal canceling this fixed speed is received.
When the main switch “AUTO CRUISE” is turned on with the vehicle in the running mode, the battery voltage is
applied to the control unit. When a signal from the control unit while the vehicle is in this state, the cruise control
actuator is activated to operate the system. Also, while the system is operating, the “AUTO CRUISE” indicator light
in the meter assembly lights up.





LTW48BSH000101
1. SET/COAST Switch Function
1. Set Function: When the SET/COAST switch is pressed and released with the main switch on, the speed at
which the vehicle is running at that moment is stored in the memory, and the vehicle automatically runs at the
stored speed.
2. COAST-down Function: When the SET/COAST switch is kept on while the vehicle in running, the vehicle
decelerates during that time. The speed at which vehicle is running when the control switch is pressed in the
memory, and the vehicle automatically returns to the stored speed.
3. Tap-down Function: When the SET/COAST switch is pressed and released instantaneously while the
vehicle is running, the vehicle decelerates a mile for each on/off operation. The vehicle speed at which the
vehicle was running when the SET/COAST was released last is stored in the memory, and the vehicle
automatically returns to this stored speed.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–1
ENGINE
CONTENTS
4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
ABBREVIATION CHARTS ........................ 6E-9
4JA1-TC .................................................... 6E-10
4JH1-TC .................................................... 6E-11
ECM CIRCUIT DIAGRAM (4JA1-TC) ........ 6E-14
ECM CIRCUIT DIAGRAM (4JA1-TC) ........ 6E-15
ECM CIRCUIT DIAGRAM (4JH1-TC) ........ 6E-16
ECM CIRCUIT DIAGRAM (4JH1-TC) ........ 6E-17
GROUND POINT CHART GENERAL EXPORT
(LHD) (1/4) ............................................... 6E-18
LOCATION ................................................ 6E-34
PARTS LOCATION ................................... 6E-39
CONNECTOR LIST ................................... 6E-40
RELAY AND FUSE .................................... 6E-43
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-43
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-44
FUSE AND RELAY LOCATION (LHD & RHD) 6E-45
ECM WIRING DIAGRAM (1/7) .................. 6E-46
ECM WIRING DIAGRAM (2/7) .................. 6E-47
ECM WIRING DIAGRAM (3/7) .................. 6E-48
ECM WIRING DIAGRAM (4/7) .................. 6E-49
ECM WIRING DIAGRAM (5/7) .................. 6E-50
ECM WIRING DIAGRAM (6/7) .................. 6E-51
ECM WIRING DIAGRAM (7/7) .................. 6E-52
ECM CONNECTOR PIN ASSIGNMENT &
OUTPUT SIGNAL .................................... 6E-53
GENERAL DESCRIPTION FOR ECM AND
SENSORS ............................................... 6E-64
Engine Control Module (ECM) ................... 6E-64
Pump Control Unit (PSG) & Data Ex change
Between Control Module ......................... 6E-64
Mass Air Flow (MAF) Sensor & Intake Air
Temperature (IAT) Sensor ....................... 6E-65
Throttle Position Sensor (TPS) .................. 6E-66
Crankshaft Position (CKP) Sensor ............ 6E-66
Engine Coolant Temperature (ECT) Sensor 6E-67
Vehicle Speed Sensor (VSS) .................... 6E-67
GENERAL DESCRIPTION FOR EGR
(EXHAUST GAS RE-CIRCULATION) ..... 6E-68
GENERAL DESCRIPTION FOR
INJECTION PUMP .................................. 6E-70Outline ....................................................... 6E-70
Cross-section View .................................... 6E-70
Low Pressure Fuel Circuit .......................... 6E-71
High Pressure Fuel Circuit ......................... 6E-72
Pump Camshaft Speed Sensor ................. 6E-72
High Pressure Solenoid Valve ................... 6E-73
Timing Control Valve (TCV) ....................... 6E-74
ISUZU Strategy Based Diagnostics .............. 6E-76
Overview .................................................... 6E-76
STRATEGY BASED DIAGNOSTICS CHART 6E-76
Diagnostic Thought Process ...................... 6E-77
1. Verify the Complaint .............................. 6E-77
2. Perform Preliminary Checks .................. 6E-77
3. Check Bulletins and Troubleshooting Hints 6E-78
4. Perform Service Manual Diagnostic Checks 6E-78
5a and 5b. Perform Service Manual Diagnostic
Procedures .............................................. 6E-78
5c. Technician Self Diagnoses .................. 6E-78
5d. Intermittent Diagnosis .......................... 6E-79
5e. Vehicle Operates as Designed ............ 6E-80
6. Re-examine the complaint ..................... 6E-81
7. Repair and Verify Fix ............................. 6E-81
GENERAL SERVICE INFORMATION ....... 6E-82
ON-BOARD DIAGNOSTIC (OBD) ............. 6E-82
TECH 2 OPERATING FLOW CART
(START UP) ............................................. 6E-86
TYPICAL SCAN DATA & DEFINITIONS
(ENGINE DATA) ................................... 6E-88
TYPICAL SCAN DATA & DEFINITIONS
(ENGINE DATA) ................................... 6E-90
MISCELLANEOUS TEST .......................... 6E-92
Plotting Snapshot Graph ............................ 6E-93
Plotting Graph Flow Chart (Plotting graph
after obtaining vehicle information) .......... 6E-94
Flow Chart for Snapshot Replay
(Plotting Graph) ....................................... 6E-95
SNAPSHOT DISPLAY WITH TIS2000 ...... 6E-96
ON-BOARD DIAGNOSTIC (OBD) SYSTEM
CHECK .................................................... 6E-105
Circuit Description ...................................... 6E-105
Diagnostic Aids .......................................... 6E-105
Test Description ......................................... 6E-105

6E–46 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
ECM WIRING DIAGRAM (1/7)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–47
ECM WIRING DIAGRAM (2/7)

6E–48 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
ECM WIRING DIAGRAM (3/7)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–49
ECM WIRING DIAGRAM (4/7)