Normal Operation and Fault Conditions

When a network message is suspected as missing or confirmed by a missing message DTC (U-code), its important to look for other conditions that may also be present in additional modules throughout the vehicle. Once a DTC sets in the TCM, it may be helpful to review the complete message list available in the ENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS (EXCEPT DIESEL & HYBRID) and see what other modules also rely on the same message and run the self-test for those modules. If the message is missing from other modules, the same DTC may also set in those modules. Confirmation of missing messages common to multiple modules may indicate that the originating module is the source of the concern or the communication network may be experiencing some problems.