U0404

U0404-IMPLAUSIBLE DATA RECEIVED FROM ESM

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 Electronic Shift Module (ESM).





Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

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.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test.

No

- Go To 2

2. ELECTRONIC SHIFT MODULE DTCs PRESENT
1. With the scan tool, read Electronic Shift Module (ESM) DTCs.

Are there any ESM DTCs present?

Yes

- Perform the appropriate diagnostic procedure.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test.

No

- Using the schematics as a guide, check the Transmission Control Module (TCM) connectors and 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 TCM.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. NAG1 Transmission Verification Test.