Bus Messages Missing

Possible Causes:

Testing

NOTE: The CMTC self test can performed manually or by using the DRBIII(R).

Turn the ignition off. Perform the CMTC self test. To perform CMTC self test manually, depress and hold the STEP and C/T CMTC buttons while turning the ignition on. Does the CMTC display "PASS"? If yes, go to next step. If no, go to step 4 .
Turn the ignition on. With the DRBIII(R), select Body Computer, System Tests then PCM Monitor. Does the DRBIII(R) display "PCM Active on the Bus"? If yes, go to next step. If no, refer to COMMUNICATION in DIAGNOSTIC TROUBLE CODE IDENTIFICATION or SYMPTOM IDENTIFICATION tables for the related symptom(s).
Turn the ignition on. With the DRBIII(R), attempt to I/D or communicate with the BCM. Was the DRBIII(R) able to I/D or communicate with the BCM? If yes, replace the Compass Mini-Trip Computer OVERHEAD CONSOLES - LIBERTY for REMOVAL & INSTALLATION. Perform BODY VERIFICATION TEST . If no, refer to COMMUNICATION in DIAGNOSTIC TROUBLE CODE IDENTIFICATION or SYMPTOM IDENTIFICATION tables for the related symptom(s).
Turn the ignition off. Perform the CMTC self test. Does the CMTC display "BUS"? If yes, refer to symptom BUS +/- Signals Open Or No Response From Compass Mini-Trip Computer in the COMMUNICATION category. If no, the condition is not present at this time. Monitor DRBIII(R) parameters while wiggling the related wire harness. Refer to any Technical Service Bulletins (TSB) that may apply. Visually inspect the related wiring harness and connector terminals.