2014 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

U1512-IMPLAUSIBLE MESSAGE DATA LENGTH RECEIVED FROM SCM

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.



Possible Causes

TIPM CAN BUS DTCS PRESENT
STEERING CONTROL MODULE (SCM) DTCS PRESENT
TRANSMISSION CONTROL MODULE (TCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).


1. CHECK FOR TIPM CAN BUS DTCS


1. With the scan tool, read TIPM DTCs.


Are there any TIPM CAN BUS DTCs present?

Yes


No


2. ELECTRONIC SHIFT MODULE DTCS PRESENT


1. With the scan tool, read Steering Control Module (SCM) DTCs.


Are there any SCM DTCs present?

Yes


No