Transmission Control Module (TCM) - 8HP45

U0103-LOST COMMUNICATION WITH ELECTRIC GEAR SHIFT MODULE

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The Transmission Control Module (TCM) receives information from the Electronic Shift Module (ESM) over a dedicated CAN C BUS. The CAN C BUS is a high speed communication BUS that allows real time control capability between these controllers.

- When Monitored:
Continuously with the ignition on.

- Set Condition:
The DTC will set if a valid CAN ID was not received in the required time from the ESM.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 8HP45 Pre-Diagnostic Troubleshooting Procedure

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

Are any ESM CAN BUS DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Using the schematics as a guide, check the Transmission Control Module Assembly (TCMA) terminals for corrosion, damage or terminal push out. If no problems are found, replace and program the TCMA. Valve Body - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.