2004 ISUZU TF SERIES check engine

ENGINE ELECTRICAL 6D – 33
PRE-HEATING SYSTEM
INSPECTION AND REPAIR
Make the necessary adjustments, repairs, and part replacement if excessive wear of damage is discovered during
inspection.

VISUAL CHECK
Check the main fuses and glow indicator for damage.
Replace the part(s) if required.
GLOW RELAY
The glow relay is located in the relay box the engine
compartment.



825R300046




Use an ohmmeter to measure the resistance between
terminals No.2 and No.3.
If the measured value is outside the specified range, the
glow relay must be replaced.
Glow Relay Resistance Ohms
94  114

GLOW PLUG


LNW21KSH001401
Use a circuit tester to test the glow plugs for continuity.
Glow Plug Resistance (Reference) Ohms
Approximately 0.9

EGR SYSTEM 4JA1T (L)
Refer to 6F-9. (EGR system diagram)

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–2 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
On-Board Diagnostic (OBD) System Check 6E-106
NO CHECK ENGINE LAMP (MIL) ............. 6E-109
Circuit Description ..................................... 6E-109
Diagnostic Aids .......................................... 6E-109
No Check Engine Lamp (MIL) ................... 6E-110
CHECK ENGINE LAMP (MIL) “ON” STEADY 6E-112
Circuit description ...................................... 6E-112
Diagnostic Aids .......................................... 6E-112
Check Engine Lamp (MIL) On Steady ....... 6E-113
ECM Diagnostic Trouble Codes ................ 6E-114
DIAGNOSTIC TROUBLE CODE (DTC) P0100
(SYMPTOM CODE 7) (FLASH CODE 65)
MASS AIR FLOW (MAF) SENSOR
VOLTAGE SUPPLY CIRCUIT HIGH INPUT 6E-128
DIAGNOSTIC TROUBLE CODE (DTC) P0100
(SYMPTOM CODE 9) (FLASH CODE 65)
MASS AIR FLOW (MAF) SENSOR
VOLTAGE SUPPLY CIRCUIT LOW INPUT 6E-128
DIAGNOSTIC TROUBLE CODE (DTC) P0100
(SYMPTOM CODE B) (FLASH CODE 65)
MASS AIR FLOW (MAF) SENSOR OUTPUT
CIRCUIT LOW INPUT ............................. 6E-128
DIAGNOSTIC TROUBLE CODE (DTC) P0100
(SYMPTOM CODE C) (FLASH CODE 65)
MASS AIR FLOW (MAF) SENSOR OUTPUT
CIRCUIT HIGH INPUT ............................ 6E-128
Circuit Description ..................................... 6E-129
Diagnostic Aids .......................................... 6E-129
Diagnostic Trouble Code (DTC) P0100
(Symptom Code 7) (Flash Code 65) Mass
Air Flow (MAF) Sensor Voltage Supply
Circuit High Input ..................................... 6E-129
Diagnostic Trouble Code (DTC) P0100
(Symptom Code 9) (Flash Code 65) Mass
Air Flow (MAF) Sensor Voltage Supply
Circuit Low Input ...................................... 6E-132
Diagnostic Trouble Code (DTC) P0100
(Symptom Code B) (Flash Code 65) Mass
Air Flow (MAF) Sensor Output Circuit Low
Input ......................................................... 6E-134
Diagnostic Trouble Code (DTC) P0100 (Symptom
Code C) (Flash Code 65) Mass Air Flow (MAF)
Sensor Output Circuit High Input ............. 6E-137
DIAGNOSTIC TROUBLE CODE (DTC) P0105
(SYMPTOM CODE 1) (FLASH CODE 34)
VACUUM PRESSURE SENSOR CIRCUIT HIGH
INPUT ...................................................... 6E-140
DIAGNOSTIC TROUBLE CODE (DTC) P0105
(SYMPTOM CODE 2) (FLASH CODE 34)
VACUUM PRESSURE SENSOR CIRCUIT
LOW INPUT ............................................. 6E-140
DIAGNOSTIC TROUBLE CODE (DTC) P0105
(SYMPTOM CODE 7) (FLASH CODE 34) VACUUM PRESSURE SENSOR VOLTAGE
SUPPLY CIRCUIT HIGH INPUT ............. 6E-140
DIAGNOSTIC TROUBLE CODE (DTC) P0105
(SYMPTOM CODE 9) (FLASH CODE 34)
VACUUM PRESSURE SENSOR VOLTAGE
SUPPLY CIRCUIT LOW INPUT .............. 6E-140
Circuit description ...................................... 6E-141
Diagnostic Aids .......................................... 6E-141
Diagnostic Trouble Code (DTC) P0105
(Symptom Code 1) (Flash Code 34) Vacuum
Pressure Sensor Circuit High Input ......... 6E-142
Diagnostic Trouble Code (DTC) P0105
(Symptom Code 2) (Flash Code 34) Vacuum
Pressure Sensor Circuit Low Input ........... 6E-145
Diagnostic Trouble Code (DTC) P0105
(Symptom Code 7) (Flash Code 34) Vacuum
Pressure Sensor Voltage Supply Circuit
High Input ................................................. 6E-148
Diagnostic Trouble Code (DTC) P0105
(Symptom Code 9) (Flash Code 34) Vacuum
Pressure Sensor Voltage Supply Circuit Low
Input .......................................................... 6E-150
DIAGNOSTIC TROUBLE CODE (DTC) P0110
(SYMPTOM CODE 1) (FLASH CODE 23)
INTAKE AIR TEMPERATURE (IAT) SENSOR
CIRCUIT HIGH INPUT ............................ 6E-152
DIAGNOSTIC TROUBLE CODE (DTC) P0110
(SYMPTOM CODE 2) (FLASH CODE 23)
INTAKE AIR TEMPERATURE (IAT) SENSOR
CIRCUIT LOW INPUT ............................. 6E-152
Circuit Description ...................................... 6E-152
Diagnostic Aids .......................................... 6E-153
Diagnostic Trouble Code (DTC) P0110
(Symptom Code 1) (Flash Code 23) Intake Air
Temperature (IAT) Sensor Circuit High Input 6E-153
Diagnostic Trouble Code (DTC) P0110
(Symptom Code 2) (Flash Code 23) Intake Air
Temperature (IAT) Sensor Circuit Low Input 6E-157
DIAGNOSTIC TROUBLE CODE (DTC) P0115
(SYMPTOM CODE 1) (FLASH CODE 14)
ENGINE COOLANT TEMPERATURE SENSOR
CIRCUIT HIGHINPUT ............................. 6E-160
DIAGNOSTIC TROUBLE CODE (DTC) P0115
(SYMPTOM CODE 2) (FLASH CODE 14)
ENGINE COOLANT TEMPERATURE SENSOR
CIRCUIT LOW INPUT ............................. 6E-160
Circuit Description ...................................... 6E-160
Diagnostic Aids .......................................... 6E-161
Diagnostic Trouble Code (DTC) P0115
(Symptom Code 1) (Flash Code 14) Engine
Coolant Temperature Sensor Circuit
HighInput ................................................. 6E-161
Diagnostic Trouble Code (DTC) P0115

6E–8 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
(SYMPTOM CODE B) (FLASH CODE 76) ECM
MAIN RELAY SWITCHED OFF TOO LATE 6E-337
Circuit Description ..................................... 6E-337
Diagnostic Aids .......................................... 6E-337
Diagnostic Trouble Code (DTC) P1625
(Symptom Code A) (Flash Code 76) ECM
Main Relay Switched Off Too Early ......... 6E-338
Diagnostic Trouble Code (DTC) P1625
(Symptom Code B) (Flash Code 76) ECM
Main Relay Switched Off Too Late .......... 6E-339
DIAGNOSTIC TROUBLE CODE (DTC) P1630
(SYMPTOM CODE A) (FLASH CODE 51)
FUEL INJECTION QUANTITY CIRCUIT
MALFUNCTION ....................................... 6E-340
DIAGNOSTIC TROUBLE CODE (DTC) P1630
(SYMPTOM CODE B) (FLASH CODE 51)
FUEL INJECTION QUANTITY CIRCUIT
MALFUNCTION ....................................... 6E-340
Circuit Description ..................................... 6E-340
Diagnostic Aids .......................................... 6E-341
Diagnostic Trouble Code (DTC) P1630
(Symptom Code A) (Flash Code 51) Fuel
Injection Quantity Circuit Malfunction ...... 6E-341
Diagnostic Trouble Code (DTC) P1630
(Symptom Code B) (Flash Code 51) Fuel
Injection Quantity Circuit Malfunction ...... 6E-341
DIAGNOSTIC TROUBLE CODE (DTC) P1650
(SYMPTOM CODE A)
(FLASH CODE 44) CAN DEVICE OFFLINE 6E-342
DIAGNOSTIC TROUBLE CODE (DTC) P1650
(SYMPTOM CODE B) (FLASH CODE 44)
CAN DEVICE HANG-UP ......................... 6E-342
Circuit Description ..................................... 6E-342
Diagnostic Aids .......................................... 6E-342
Diagnostic Trouble Code (DTC) P1650
(Symptom Code A) (Flash Code 44)
CAN Device Offline .................................. 6E-343
Diagnostic Trouble Code (DTC) P1650
(Symptom Code B) (Flash Code 44)
CAN Device Hang-up .............................. 6E-348
DIAGNOSTIC TROUBLE CODE (DTC) P1651
(SYMPTOM CODE A) (FLASH CODE 45)
CAN MALFUNCTION .............................. 6E-349
DIAGNOSTIC TROUBLE CODE (DTC) P1651
(SYMPTOM CODE B) (FLASH CODE 45)
CAN RECEIVES ERROR ........................ 6E-349
Circuit Description ..................................... 6E-349
Diagnostic Aids .......................................... 6E-349
Diagnostic Trouble Code (DTC) P1651
(Symptom Code A) (Flash Code 45)
CAN Malfunction ...................................... 6E-350
Diagnostic Trouble Code (DTC) P1651
(Symptom Code B) (Flash Code 45) CAN Receives Error ................................ 6E-351
DIAGNOSTIC TROUBLE CODE (DTC) P1690
(SYMPTOM CODE 4) (FLASH CODE 77)
CHECK ENGINE LAMP (MIL) CIRCUIT
VOLTAGE LOW ...................................... 6E-356
DIAGNOSTIC TROUBLE CODE (DTC) P1690
(SYMPTOM CODE 8) (FLASH CODE 77)
CHECK ENGINE LAMP (MIL) CIRCUIT
VOLTAGE HIGH ...................................... 6E-356
Circuit Description ...................................... 6E-356
Diagnostic Aids .......................................... 6E-356
Diagnostic Trouble Code (DTC) P1690
(Symptom Code 4) (Flash Code 77) Check
Engine Lamp (MIL) Circuit Voltage Low .. 6E-357
Diagnostic Trouble Code (DTC) P1690
(Symptom Code 8) (Flash Code 77) Check
Engine Lamp (MIL) Circuit Voltage High . 6E-360
SYMPTOM DIAGNOSIS ............................ 6E-361
PRELIMINARY CHECKS .......................... 6E-361
VISUAL/PHYSICAL CHECK ...................... 6E-361
INTERMITTENT ........................................ 6E-361
ENGINE CRANKS BUT WILL NOT RUN .. 6E-362
HARD START SYMPTOM ......................... 6E-366
ROUGH, UNSTABLE, OR INCORRECT
IDLE, STALLING SYMPTOM .................. 6E-370
SURGES AND/OR CHUGS SYMPTOM ... 6E-377
HESITATION, SAG, STUMBLE SYMPTOM 6E-383
CUTS OUT, MISSES SYMPTOM .............. 6E-389
LACK OF POWER, SLUGGISH OR
SPONGY SYMPTOM .............................. 6E-396
POOR FUEL ECONOMY SYMPTOM ....... 6E-402
EXCESSIVE WHITE SMOKE .................... 6E-407
EXCESSIVE BLACK SMOKE .................... 6E-413
ON-VEHICLE SERVICE PROCEDURE .... 6E-418
ENGINE CONTROL MODULE (ECM) ... 6E-418
CRANKSHAFT POSITION (CKP) SENSOR 6E-419
ENGINE COOLANT TEMPERATURE
(ECT) SENSOR ....................................... 6E-419
MASS AIR FLOW (MAF) & INTAKE AIR
TEMPERATURE (IAT) SENSOR ............ 6E-420
THROTTLE POSITION SENSOR (TPS) ... 6E-420
EGR EVRV
(Electrical Vacuum Regulating Valve) ..... 6E-421

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–9
ABBREVIATION CHARTS
A bbreviations A ppellation
A/C Air conditioner
A/T Automatic transmission
ACC Accessory
BLK Black
BLU Blue
BRN Brown
CAN Controller Area Network
CEL Check engine lamp
CKP Crankshaft position sensor
DLC Data link connector
DTC Diagnosis trouble code
DVM Digital voltage meter
ECM Engine control module
ECT Engine coolant temperature
EEPROM Electrically erasable & programmable read only memory
EGR Ex haust gas recirculation
EVRV Electric vacuum regulating valve
GND Ground
GRY Gray
IAT Intake air temperature
IG Ignition
M/T Manual transmission
MAB High pressure solenoid valve cutoff (German abbreviation)
MAF Mass air flow
MIL Malfunction indicator lamp
OBD On-board diagnostic
ORN Orange
PNK Pink
RED Red
PSG Pump control unit (German abbreviation)
SW Switch
TCM Transmission control module
TCV Timing control valve
TDC Top dead center
TPS Throttle position sensor
VCC Voltage constunt control
VIO Violet
VSS Vehicle speed sensor
WHT Whi te
YEL Yellow

6E–40 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
CONNECTOR LIST
No. Connector face No. Connector face
B-24
Green Meter-BC-56
ECM-A
B-54
White J/B I2C-57
ECM-B
B-56
White J/B I4C-77
Clutch switch
B-58
Black Check connectorC-94
White TCM
B-62
White Ignition switch (IGSUB : G1)C-95
White TCM
B-63
White Ignition switch (IGSUB : G2)C-107
White J/B E2
B-68
ImmobilizerC-108
White J/B E1
C-2
Silver Engine room-RH groundC-109
Silver Body-LH ; ground
C-36
Silver Engine room-LH ; GroundC-115
Brown EVRV
C-44
White Stop lamp switchC-116

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–59
3737No Connection---------
38 38 Throttle Po sitio n
Se nso r (TPS) Out-
put Signa lGRN/
ORGLe ss
tha n 1VLess than 1V Approx.
0.5VCo nnect DC V 38 49
39 39 Ke y Switch Input Sig-
nal Via Engine FuseWH T L e s s
tha n 1V10-14V Co nnect DC V 39 GND
4040No Connection---------
41 41 A/C Compressor
RelayWH T/
GRNLe ss
tha n 1V10-14V A/C comp. is o pe r-
ated: Less than 1V
A/C comp. is no t o pe r-
ate d: 10 - 14VCo nnect DC V 41 GND
42 42 Check Engine La mp GRN/
YELLe ss
tha n 1VLamp is turned on: Less than 1V
Lamp is turned off: 10-14VCo nnect DC V 42 GND
43 43 Glo w Lamp ORG/
BLULe ss
tha n 1VLamp is turned on: Less than 1V
Lamp is turned off: 10-14VCo nnect DC V 43 GND
4444No Connection---------
45 45 To Data Link Co n-
necto r No . 6BLU Less
tha n 1V10-14V Co nnect DC V 45 GND
4646No Connection---------
4747No Connection---------
4848No Connection---------
49 49 Throttle Po sitio n
Se nso r (TPS)
GroundBLK/
GRNIdle:
Appro x.
0.4K
ohm /
WO T:
Appro x.
4.0K
ohm---Discon-
ne ctOh m 3 8 4 9
5050No Connection---------
5151No Connection---------
5252No Connection---------
5353No Connection---------
5454No Connection---------
5555No Connection---------
5656No Connection---------
57 57 Throttle Po sitio n
Senso r (TPS) Po wer
SupplyRED/
GRNLe ss
tha n 1VApprox. 5V Connect DC V 57 49
58 58 ECM Re la y BLU/
BLK10-14V Less than 1V Connect DC V 58 GND
5959No Connection---------
6060No Connection---------
6161No Connection---------
6262No Connection---------Signal or Continuity Tester Position
Pin
No. B/
Box
No.Pin Function Wire
ColorKey SW
OffKey SW
OnEngine
IdleEngine
2000rpmECM
Connec-
tionRan
ge(+) (-)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–77
Diagnostic Thought Process
As you follow a diagnostic plan, every box on the
Strategy Based Diagnostics chart requires you to use
the diagnostic thought process. This method of thinking
optimizes your diagnosis in the following ways:
Improves your understanding and definition of the
customer complaint
Saves time by avoiding testing and/or replacing good
parts
Allows you to look at the problem from different
perspectives
Guides you to determine what level of understanding
about system operation is needed:
–Owner’s manual level
–Service manual level
–In-depth (engineering) level
–Owner’s manual level
–Service manual level
–In-depth (engineering) level
1. Verify the Complaint
What you should do
To verify the customer complaint, you need to know the
correct (normal) operating behavior of the system and
verify that the customer complaint is a valid failure of the
system.
The following information will help you verify the
complaint:
WHAT the vehicle model/options are
WHAT aftermarket and dealer-installed accessories
exist
WHAT related system(s) operate properly
WHEN the problem occurs
WHERE the problem occurs
HOW the problem occurs
HOW LONG the condition has ex isted (and if the
system ever worked correctly)
HOW OFTEN the problem occurs
Whether the severity of the problem has increased,
decreased or stayed the same
What resources you should use
Whenever possible, you should use the following
resources to assist you in verifying the complaint:
Service manual Theory or Circuit Description
sections
Service manual “System Performance Check”
Owner manual operational description
Technician ex perience
Identical vehicle for comparisonCircuit testing tools
Vehicle road tests
Complaint check sheet
Contact with the customer
2. Perform Preliminary Checks
NOTE: An estimated 10 percent of successful vehicle
repairs are diagnosed with this step!
What you should do
You perform preliminary checks for several reasons:
To detect if the cause of the complaint is VISUALLY
OBVIOUS
To identify parts of the system that work correctly
To accumulate enough data to correctly and
accurately search for a ISUZU Service Bulletin on
ISUZU Web site.
The initial checks may vary depending on the
complex ity of the system and may include the following
actions:
Operate the suspect system
Make a visual inspection of harness routing and
accessible/visible power and ground circuits
Check for blown fuses
Make a visual inspection for separated connectors
Make a visual inspection of connectors (includes
checking terminals for damage and tightness)
Check for any DTCs stored by the on-board
computers
Sense unusual noises, smells, vibrations or
mov ements
Investigate the vehicle service history (call other
dealerships, if appropriate)
What resources you should use
Whenever appropriate, you should use the following
resources for assistance in performing preliminary
checks:
Tech II or other technical equipment for viewing DTCs
Service manual information:
–Component locations
–Harness routing
–Wiring schematics
–Procedures for viewing DTCs
Dealership service history file
Vehicle road test
Identical vehicle or system for comparison