Transmission Control Module (TCM)

U1421-IMPLAUSIBLE IGNITION KEY OFF TIME RECEIVED

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

Theory of Operation

This message is used by the Transmission Control Module (TCM) in the transmission temperature sensor and transmission fluid temperature sensor performance detections.

When Monitored:
- Continuously with the ignition on.

Set Condition:
- This fault is set when the ignition key off time message is not received.






Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. Testing and Inspection.

1. CHECK FOR TIPM CAN BUS DTCS
1. With the scan tool, read TIPM DTCs.

Are there any TIPM CAN BUS DTCs present?

Yes

- Perform the appropriate diagnostic procedure Testing and Inspection.

No

- Go To 2

2. CHECK IF CCN DTCS ARE PRESENT
1. With the scan tool, read CCN DTCs.

Are there any CCN DTCs present?

Yes

- Perform the appropriate diagnostic procedure.Testing and Inspection
- Perform AS68RC TRANSMISSION VERIFICATION TEST AS68RC Transmission Verification Test.

No

- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCM.
- Perform AS68RC TRANSMISSION VERIFICATION TEST. AS68RC Transmission Verification Test.