Bus Messages Missing

WARNING: This page is about a different car, the 2002 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

Possible Causes:

Attempt to communicate with ACM.
CTM.

CAUTION: Always turn ignition off before disconnecting or connecting any control module connector. Failure to do so could result in damage to control module.

NOTE: Ensure vehicle being tested has a fully charged battery. If it does not, false DTCs or error messages may occur.

NOTE: For component location, see appropriate illustration under COMPONENT LOCATIONS . For terminal identification, see appropriate illustration under CONNECTOR IDENTIFICATION . For circuit and wire color identification, see WIRING DIAGRAMS . For component removal and installation procedures, see appropriate component under REMOVAL & INSTALLATION .

Testing:

Perform CMTC self-test. See CMTC SELF-CHECK under SYMPTOM TESTS. Turn ignition off. Depress and hold CMTC STEP and C/T buttons while turning ignition on. Does CMTC display PASSED? If yes, go to next step. If no, go to step 4 .
Turn ignition off. Connect DRBIII(R), if not already connected. Turn the ignition on. Using 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 appropriate COMMUNICATION symptom for diagnosis. See SYMPTOM IDENTIFICATION .
Using the DRBIII(R), attempt to identify or communicate with CTM. Is DRBIII(R) able to identify or communicate with the CTM? If yes, replace CMTC. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, refer to appropriate COMMUNICATION symptom for diagnosis. See SYMPTOM IDENTIFICATION .
Turn ignition off. Using the DRBIII(R), perform CMTC self-test. Does CMTC display BUS? If yes, refer to appropriate COMMUNICATION symptom for diagnosis. See SYMPTOM IDENTIFICATION . 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 Bulletin (TSB) that may apply. Visually inspect the related wiring harness and connector terminals. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.