CRUISE CONTROL SYSTEM 8B-17
DTC 2–1 Signal of Vehicle Speed Malfunction
Step Action Value(s) YES NO
1 Check the DTC for engine.
Is the vehicle speed sensor DTC set?
—
Go to DTC for
engine
Go to Step 2
2 Check continuity between harness side connector
E–44 terminal 3 and connector C–120 terminal 9.
Is there continuity between terminals?
—
Go to Step 3
Replace open
circuit
3 Check the continuity between harness side
connector E–44 terminal 3 and ground, connector
C–120 terminal 9 and ground.
Are the results same as specified in the value(s)
column?
No continuity
Replace the
control unit
Repair short
circuit
6A – 38 ENGINE MECHANICAL
6. Front propeller shaft (for 4x4 model)
Remove the spline yoke flange bolt at the transfer output
shaft.
Do not allow the spline yoke to fall away from the front
propeller shaft.
If the spline yoke should fall away from the front propeller
shaft, align the setting marks on the spline yoke and the
propeller shaft to reassemble the two marks. The setting
marks are punched circles approx. 3mm (0.12 in) in
diameter.
7. Clutch slave cylinder (for M/T model)
8. ATF pipe (for A/T model)
9 Shift control cable (for A/T model)
10. Transmission sensor harness
Remove the vehicle speed sensor connector, inhibitor
switch connector (A/T), ATF temperature sensor
connector, back up light switch connector (M/T) from
transmission.
11. Breather hose (for A/T model)
12. Transmission shift lever (for M/T model)
Remove the shift lever from the floor.
13. Transfer shift lever (for 4x4 model)
Remove the shift lever from the floor.
14. Transmission member
1) Support the transmission with the transmission jack.
2) Remove the transmission member mounting bolts
fixing the transmission member to the chassis frame.
15. Torque converter bolt (for A/T model)
1) Remove the under cover under the torque converter
housing.
2) Rotate the flywheel by using tire lever or some other
tool, and then remove the torque converter bolts.
16. Transmission coupling bolt
1) Support the engine with the garage jack.
2) Use the jack to slightly lower the transmission.
3) Remove the transmission coupling bolts.
17. Transmission (and transfer)
Separate the transmission (and transfer) from the
engine.Take care not to damage the transmission, the
engine, and their related parts..
F06R300007 P1010025
ENGINE MECHANICAL 6A – 39
18. Radiator
1) Drain the engine coolant.
2) Remove the reservoir hose.
3) Remove the upper and lower hose.
4) Remove the fan guide.
5) Remove the radiator.
19. Fan
P1010034
20. Air cleaner
1) Remove the MAF sensor connector (4JA1TC/4JH1TC) from air cleaner duct.
2) Remove the air cleaner duct and the air cleaner box from engine room.
3) Remove the two air ducts from inter cooler (4JA1TC/4JH1TC).
21. Power Steering Pump Loosen the power steering pump adjust plate bolt, then
remove the power steering pump assembly. Place the
power steering pump assembly along with piping on the
body side.
22. Air conditioner compressor 1) Remove air compressor magnet connector.
2) Remove the air conditioner compressor. Place the air conditioner compressor along with piping on the body
side.
23. Engine Control Cable Remove the engine control cable from its bracket
(4JA1TC/4JH1TC) or the injection pump (4JA1T(L)).
24. Vacuum Piping Remove the vacuum pipe from the vacuum pump, the
EGR valve, injection pump FICD (4JA1T(L)).
25. Engine Harness 1) Remove following connectors from engine.
TPS connector
Oil pressure switch connector
Thermo switch connector
Injection pump connector
Engine earth
Thermometer unit connector
TDC sensor
2) Remove the clips fixing engine harness.
P1010009
ENGINE MECHANICAL 6A – 53
20. Camshaft Timing Gear
1. Use a dial indicator to measure the camshaft end play.
This must be done before removing the camshaft
gear.
If the camshaft end play exceeds the specified limit,
the thrust plate must be replaced.
Camshaft End Play mm (in)
Standard Limit
0.050 - 0.114
(0.002 - 0.0044) 0.20
(0.008)
2. Remove the camshaft timing gear bolt from the
camshaft.
Note:
Hold the camshaft stationary to prevent the camshaft
from turning.
3. Remove the sensor rotor plate.
4. Use the universal puller to pull out the camshaft
timing gear.
Universal Puller: 5-8521-0002-0
5. Remove the thrust plate.
21. Camshaft Thrust Plate
22. Camshaft
Jiggle the camshaft with your hand as you pull it free from
the front of the engine.
23. Timing Gear Case
24. Cylinder Body Rear Plate
25. Piston Cooling Oil Jet
The oiling jet uses thin steel tubing which is easily bent.
Accidental contact between the oiling jet and the cylinder
body, piston, or a tool will damage the oiling jet.
Never attempt to repair a damaged oiling jet. Replace it
with a new one.
014RT0001
901R100008
014RY00019
052RY00001
ENGINE COOLING 6B – 7
DIAGNOSIS
Engine Cooling Trouble
Symptom Possible Cause Action
Low Engine Coolant level Replenish
Thermo meter unit faulty Replace
Faulty thermostat Replace
Faulty Engine Coolant temperature
sensor Repair or replace
Clogged radiator Clean or replace
Faulty radiator cap Replace
Low engine oil level or use of
improper engine oil Replenish or change oil
Clogged exhaust system Clean exhaust system or replace
faulty parts
Faulty Throttle Position sensor Replace throttle valve assembly
Open or shorted Throttle Position
sensor circuit Repair or replace
Engine overheating
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Faulty thermostat Replace Engine slow to warm–up
Thermo unit faulty Replace
6C – 20 FUEL SYSTEM
7. Power Steering Pump Bracket
6C-4 8. Throttle Position Sensor Harness Connector
(4JA1TC/4JH1TC only)
Disconnect the harness connector from the throttle
position sensor.
9. Oil Level Gauge
10. Fuel Pipe
1) Disconnect the fuel hoses from the fuel filter or priming
pump.
2) Disconnect the fuel hoses from the injection pump.
11. Fuel Filter Assembly (Except EURO III model)
6C-5
12. Fuel Filter Bracket (Except EURO III model)
13. Leak Off Hose
Disconnect the leak off hose at the injection pump.
14. Injection Pipe Clip
15. Injection Pipe
1) Loosen the injection pipe sleeve nuts at the delivery
valve side and the injection nozzle side.
Note:
Do not apply excessive force to the injection pipes.
2) Loosen the injection pipe clip.
3) Remove the injection pipes.
Note:
Plug the delivery holder ports with the caps to prevent
the entry of foreign material.
16. Intake Manifold
1) Remove the EGR valve from the intake manifold and
EGR pipe.
2) Loosen the intake rubber hoses clip.
3) Loosen the intake manifold bolts and nuts.
17. Injection Pump Cover (4JA1TC/4JH1TC only)
FUEL SYSTEM 6C – 25
13. Throttle Position Sensor Harness Connector
(4JA1TC/4JH1TC only)
Reconnect the harness connector to the throttle position
sensor.
14. Power Steering Pump Bracket
15. Fan
16. Vacuum Hose
Connect the vacuum hose to the EGR valve and the
intake throttle.
Euro under Euro I Euro II Euro III
4JA1L without with with Not used
4JA1TC Not used Not used Not used With cooler
(EGR cooler)
4JH1TC without with with With
(EGR cooler)
17. Accelerator Control Cable
1) Connect the accelerator cable to the injection pump
(4JA1T) the intake throttle. (4JA1TC/4JH1TC only)
18. Power Steering Pump Assembly
19. Drive Belt
Install the drive belt and adjust the belt tension.
20. Battery
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