2004 ISUZU TF SERIES Workshop Manual

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ISUZU TF SERIES 2004  Workshop Manual 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

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ISUZU TF SERIES 2004  Workshop Manual 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 “O

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ISUZU TF SERIES 2004  Workshop Manual 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–335
DIAGNOSTIC TROUBLE CODE (DTC) P1614 (SYMPTOM CODE A) 
(FLASH CODE 56) WRONG TRANSPONDER KEY
Condition for setting the DTC and action taken when the

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ISUZU TF SERIES 2004  Workshop Manual 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 Diagno

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ISUZU TF SERIES 2004  Workshop Manual 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 (SY

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ISUZU TF SERIES 2004  Workshop Manual 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

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ISUZU TF SERIES 2004  Workshop Manual 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 “

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ISUZU TF SERIES 2004  Workshop Manual 6E–340 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P1630 (SYMPTOM CODE A) 
(FLASH CODE 51) FUEL INJECTION QUANTITY CIRCUIT MALFUNCTION
DIAGNOSTIC TROUBLE CODE (DTC) P16