P1603-PCM INTERNAL DUAL-PORT RAM COMMUNICATION FAILURE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Offf,
Run, Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P1604-PCM INTERNAL DUAL-PORT RAM READ/WRITE INTEGRITY FAILURE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Off, Run,
Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P1607-PCM INTERNAL SHUTDOWN TIMER SLOW RATIONALITY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Off, Run,
Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P1696-EEPROM MEMORY WRITE DENIED/INVALID
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Continuously with the ignition on.
Set Condition:
An attempt to program/write to the internal EEPROM failed, Also checks at power down. One Trip Fault. Three
good trips to turn off the MIL.
Possible Causes
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.SCAN TOOL DISPLAYS A WRITE FAILURE
With a scan tool, perform the SRI Memory Test.
Does scan tool display Write Failure?
Ye s>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.SCAN TOOL DISPLAYS A WRITE REFUSED
With the a scan tool, perform the SRI Memory Test.
Does the scan tool display Write Refused?
Ye s>>
Go To 3
No>>
Go To 4
3.PCM REFUSED 2ND TEST
With a scan tool, perform the SRI Memory Test a third time.
NOTE: Retest the SRI Memory two more times.
Does the scan tool display Write Refused again?
Ye s>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
4.SCAN TOOL DISPLAYS SRI MILEAGE INVALID
With a scan tool, perform the SRI Memory Test.
Does the scan tool display SRI Mileage Invalid?
Ye s>>
Update the mileage and retest the SRI Memory.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
P1697-EMR (SRI) MILEAGE NOT STORED
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Continuously with the ignition on.
Set Condition:
An attempt to program/write to the internal EEPROM failed, Also checks at powerdown. One Trip Fault. Three
good trips to turn off the MIL.
Possible Causes
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.SCAN TOOL DISPLAYS A WRITE FAILURE
With a scan tool, perform the SRI Memory Test.
Does scan tool display Write Failure?
Ye s>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.SCAN TOOL DISPLAYS A WRITE REFUSED
With the a scan tool, perform the SRI Memory Test.
Does the scan tool display Write Refused?
Ye s>>
Go To 3
No>>
Go To 4
3.PCM REFUSED 2ND TEST
With a scan tool, perform the SRI Memory Test a third time.
NOTE: Retest the SRI Memory two more times.
Does the scan tool display Write Refused again?
Ye s>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
4.SCAN TOOL DISPLAYS SRI MILEAGE INVALID
With a scan tool, perform the SRI Memory Test.
Does the scan tool display SRI Mileage Invalid?
Ye s>>
Update the mileage and retest the SRI Memory.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
P2610-PCM INTERNAL SHUTDOWN TIMER FAST RATIONALITY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on and battery voltage greater than 10 volts.
Set Condition:
Internal PCM failure detected. One Trip Fault. Three good trips to turn offthe MIL.
Possible Causes
PCM FUSED IGNITION SWITCH CIRCUIT
PCM INTERNAL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM IGNITION CIRCUITS
Turn the ignition off.
Disconnect the C1 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch circuits.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Off, Run,
Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM
The Powertrain Control Module is reporting internal errors.
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
U0101-LOST COMMUNICATION WITH TCM
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition run time is greater than 1 second. Battery voltage between 9 and 16volts. Engine run time greater
than 3 seconds.
Set Condition:
The PCM doesn’t receive a Bus Message from the Transmission Control Modulefor 7 consecutive seconds.
One trip failure. The circuit is continuously monitored.
Possible Causes
PCM FUSED IGNITION SWITCH OUTPUT CIRCUIT CHECK
BUS FAILURE OPEN OR SHORTED CONDITION
PCI BUS UNABLE TO COMMUNICATE WITH THE SCAN TOOL
PCM
Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic
procedures and for further possible causes.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With the scan tool, erase DTCs.
Cycle the ignition key on and off several times. Leaving the ignition on forat least 20 seconds.
With the scan tool, read DTCs.
Does the DTC reset?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.PCM FUSED IGNITION SWITCH OUTPUT CIRCUIT
Turn the ignition off.
Disconnect the C1 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
With a 12-volt test light connected to ground and with special tool
#8815 installed, probe the (F202), (F1), and (T751) Fused Ignition
Switch Output circuit.
Perform the above check with the Ignition key in the off lock position,
Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the
test light to try to interrupt the circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the excessive resistance in the (F202), (F1), and (T751) Fused Ignition Switch (Off, Run, Start)
circuit. Inspect the related fuse, if the fuse is open check the circuit fora short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P0381-WAIT TO START LAMP INOPERATIVE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on.
Set Condition:
The cluster sends a signal to the ECM that it has detected a failed wait to start lamp.
Possible Causes
FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
WAIT-TO-START LIGHT BULB
WIRING/CONNECTOR PROBLEM
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.WAIT-TO-START LAMP DOES NOT COME ON
Turn the ignition off.
While watching the wait-to-start lamp, turn the ignition key on.
Did the wait-to-start lamp light?
Ye s>>
Go To 2
No>>
Go To 3
2.WAIT-TO-START LAMP STAYS ON ALL THE TIME
Turn the ignition off.
While watching the wait-to-start lamp, turn the ignition key on.
Does the wait-to-start lamp stay on all the time?
Ye s>>
Go To 3
No>>
Wait-to-start Lamp operating normally. Test passed.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)