U1508-IMPLAUSIBLE MESSAGE DATA LENGTH RECEIVED FROM ESM

U1508-IMPLAUSIBLE MESSAGE DATA LENGTH 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 Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).

1. CHECK FOR CAN BUS DTCS

• Refer to DTC Based Diagnostics and perform the appropriate diagnostic procedure.
• Perform the NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).

• Go To 2

2. ELECTRONIC SHIFT MODULE DTCS PRESENT

• (Refer to 28 - DTC-Based Diagnostics/MODULE, Electronic Shift (ESM) - Diagnosis and Testing) and perform the appropriate diagnostic procedure.

• 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 in accordance with the Service Information.
• Perform the NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).