Transmission Control Module (TCM) - 8HP45

U0403-IMPLAUSIBLE DATA RECEIVED FROM T-CASE

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The messages sent on the CAN BUS are distinguished by an identifier (ID). Each CAN ID is defined to contain a certain number of bytes. The Transmission Control Module (TCM) verifies that it has received the proper number of bytes for each ID.

- When Monitored:
Continuously with the ignition on, one valid CAN ID received at least once, and no U0002-CAN BUS Off Performance DTC present.

- Set Condition:
When the TCM detects an incorrect CAN ID from the Drivetrain Control Module (DTCM).





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

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

Are any BCM CAN BUS DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure. Perform the diagnostic procedure for DTC U0001-CAN C BUS first.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Go To 2

2. DRIVETRAIN CONTROL MODULE (DTCM) DTCS PRESENT
1. With the scan tool, read Drivetrain Control Module (DTCM) DTCs.

Are any DTCM DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Using the schematics as a guide, check the Transmission Control Module Assembly (TCMA) terminals 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 TCMA. Valve Body - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.