P1002
P1002-IGNITION KEY OFF TIMER PERFORMANCE - TOO SLOW
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
Theory of Operation
The Transmission Control Module (TCM) uses ignition off time to enable other diagnostic tests. The TCM must verify proper operation of the ignition off timer to insure the diagnostic tests are performed within the proper enable conditions. The ignition off timer value is stored in the Cabin Compartment Node (CCN). The CCN will send the ignition off time message to the Totally Integrated Power Module (TIPM). The TIPM broadcasts the ignition off time over the CAN buss. The TCM receives the message and then compares the ignition off timer value to the Engine Coolant Ignition off temperature and the Engine Coolant Start-up Temperature message. The DTC will set if the ignition off time is less than a calibrated value based on Engine Coolant Ignition off Temperature and the Engine Coolant Start-up Temperature.
When Monitored:
- Ignition on.
- No CAN bus DTCs.
- Ambient air temp is greater than -9° C (15° F).
Set Condition:
- Ignition off time is less than a calibrated value based on Engine Coolant Ignition Off Temperature and the Engine Coolant Start-up Temperature.
Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. Testing and Inspection.
1. CHECK FOR ACTIVE DTC
NOTE: If the TCM detects and stores a DTC, the TCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
1. Using the scan tool, read TCM DTCs.
2. Record the Environmental Data and any DTCs.
3. Clear DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. Read TCM DTCs.
Did this DTC set again?
Yes
- Go To 2
No
- Go To 6
2. CHECKING FOR OTHER DTCS
1. Turn the ignition on.
2. Does the scan tool display any CCN and TIPM DTCs.
NOTE: Any TCM communication related DTCs TIPM must be diagnosed and corrected before continuing to diagnose this DTC.
Are there any TCM communication related DTCs in the TIPM?
Yes
- Perform the appropriate diagnostic procedure.Testing and Inspection
No
- Go To 3
3. CHECKING THE ECT OPERATION
1. Perform the diagnostic procedure for P0116 as if it is active. P0116
Is the ECT Sensor operating correctly?
Yes
- Go To 4
No
- Repair or replace as necessary.
- Perform AS68RC TRANSMISSION VERIFICATION TEST AS68RC Transmission Verification Test.
4. IGNITION SWITCH
1. Refer to the Wiring Information and verify proper ignition switch operation. Turn the ignition key to each position and verifying correct voltage output by back probing the corresponding ignition switch harness connector cavity.
Is the Ignition Switch functioning properly?
Yes
- Go To 5
No
- Repair or replace Ignition Switch, wiring or connectors as necessary.
- Perform AS68RC TRANSMISSION VERIFICATION TEST AS68RC Transmission Verification Test.
5. VERIFY THAT THE CCN IS ACTIVE ON THE BUS
1. With the scan tool, select ECU View.
2. Verify that the CCN is active on the bus.
Is the CCN active on the bus?
Yes
- Replace the Cabin Compartment Node (CCN).
- Perform the BODY VERIFICATION TEST Body Verification Test.
No
- Perform the No Response from TCM diagnostic procedures. No Response From TCM (Transmission Control Module)
6. CHECK WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.
4. Check for any Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform AS68RC TRANSMISSION VERIFICATION TEST AS68RC Transmission Verification Test.
No
- Test Complete.