ignition ISUZU TF SERIES 2004 Workshop Manual
[x] Cancel search | Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 1700 of 4264

6E–328 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
8 Using the DVM and check the ECM and immobilizer
control unit communication circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the immobilizer control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 9Repair faulty
harness and
verify repair
9 Using the DVM and check the ECM and immobilizer
control unit communication circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM
disconnected) Ref. Page 6E-103
3. Disconnect the immobilizer control unit connector.
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the the immobilizer control unit
connector and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 10 Step Action Value(s) Yes No
8
V
B-68
B-6835Breaker Box
35
8
C-56
B-68
Page 1703 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–331
Diagnostic Trouble Code (DTC) P1613 (Symptom Code A) (Flash Code 56)
Immobilizer No or Wrong Signal
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P1613 (Symptom Code A) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P1613 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “Immobilizer” in the system selection menu
“Body”.
3. Select “Read DTC Info Ordered By Priority” in the
“Diagnositic Trouble Code”.
Was the any DTC's B**** stored in this ignition cycle?—Refer to
“Immobilizer
Workshop
Manual” & Go
to DTC Chart
B**** Go to Step 5
5 Check for poor/faulty connection at the immobilizer
control unit connector or ECM connector. If a poor/
faulty connection is found, repair as necessary.
Was the problem found?
—Verify repair Go to Step 6
42
35
78 C-56
B-68
Page 1704 of 4264

6E–332 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
6 Using the DVM and check the “CHECK ENGINE”
lamp circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the meter connector and immobilizer
control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was DVM indicated specified value?
Less than 1V Go to Step 7Repair faulty
harness and
verify repair Step Action Value(s) Yes No
7
V
B-68
Page 1705 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–333
7 Using the DVM and check the “CHECK ENGINE”
lamp circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM
disconnected) Ref. Page 6E-103
3. Disconnect the immobilizer control unit connector.
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the the immobilizer control unit
connector and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 8
8 Using the DVM and check the ECM and immobilizer
control unit communication circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the immobilizer control unit connector.
3. Ignition “On”.
4. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V Go to Step 9Repair faulty
harness and
verify repair Step Action Value(s) Yes No
B-6 842Breaker Box
42
7
C-56
B-68
8
V
B-68
Page 1706 of 4264

6E–334 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
9 Using the DVM and check the ECM and immobilizer
control unit communication circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM
disconnected) Ref. Page 6E-103
3. Disconnect the immobilizer control unit connector.
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the the immobilizer control unit
connector and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 10
10 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 11
11 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Verify repair— Step Action Value(s) Yes No
B-6835Breaker Box
35
8
C-56
B-68
Page 1708 of 4264

6E–336 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1614 (Symptom Code A) (Flash Code 56)
Wrong Transponder Key
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P1614 (Symptom Code A) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P1614 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “Immobilizer” in the system selection menu
“Body”.
3. Select “Read DTC Info Ordered By Priority” in the
“Diagnostic Trouble Code”.
Was the any DTC's B**** stored in this ignition cycle?—Refer to
“Immobilizer
Workshop
Manual” & Go
to DTC Chart
B**** Go to Step 5
5 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 6
6 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must e
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Verify repair—
Page 1709 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–337
DIAGNOSTIC TROUBLE CODE (DTC) P1625 (SYMPTOM CODE A)
(FLASH CODE 76) ECM MAIN RELAY SWITCHED OFF TOO EARLY
DIAGNOSTIC TROUBLE CODE (DTC) P1625 (SYMPTOM CODE B)
(FLASH CODE 76) ECM MAIN RELAY SWITCHED OFF TOO LATE
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM switches ECM main relay to operate ECM
and other sensors or controller.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Flash
CodeCode Symptom
CodeMIL DTC Name DTC Setting Condition Fail-Safe (Back Up)
76 P1625 A OFF ECM Main Relay Switche d
Off Too Ea rlyWhen ignition switch was
turne d off, timing of the ECM
main re la y turning off is to o
early.No fa il-sa fe fun ctio n.
B OFF ECM Main Relay Switched
Off Too LateWhen ignition switch was
turne d off, timing of the ECM
main re la y turning off is to o
late or does not off.
Page 1710 of 4264

6E–338 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
Broken wire inside the insulation.
Check for the following conditions:
Poor connection at ECM-Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the “Main Relay” display on the Tech2 while moving
connectors and wiring harnesses. A change in the
display will indicate the location of the fault.
Diagnostic Trouble Code (DTC) P1625 (Symptom Code A) (Flash Code 76)
ECM Main Relay Switched Off Too Early
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P1625 (Symptom Code A) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P1625 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 5
5 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Verify repair—
Page 1711 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–339
Diagnostic Trouble Code (DTC) P1625 (Symptom Code B) (Flash Code 76)
ECM Main Relay Switched Off Too Late
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P1625 (Symptom Code B) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P1625 (Symptom Code B) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Using the DVM and check the ECM main relay.
1. Ignition “Off”, engine “Off”.
2. Remove the ECM main relay from the relay box .
3. Check the relay switch.
Was the DVM indicated specified value?
No continuitly Go to Step 5Replace ECM
main relay and
verify repair
5 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 6
6 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Verify repair—
ECM Main Relay
Page 1713 of 4264

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–341
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.Broken wire inside the insulation.
Check for the following conditions:
Poor connection at ECM and PSG-Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.
Diagnostic Trouble Code (DTC) P1630 (Sy mptom Code A) (Flash Code 51) Fuel
Injection Quantity Circuit Malfunction
Diagnostic Trouble Code (DTC) P1630 (Sy mptom Code B) (Flash Code 51) Fuel
Injection Quantity Circuit Malfunction
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P1630 (Symptom Code A) or P1630
(symptom Code B) stored as “Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P1630 (Symptom Code A) or P1630
(symptom Code B) stored in this ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
4 Replace the injection pump assembly.
Is the action complete?—Verify repair—