EATX Bus Communication Failure
NOTE:
After making any repairs, perform BODY CONTROL MODULES SYSTEM VERIFICATION TEST
under VERIFICATION TESTS.
Monitored & Set Condition
- When Monitored: With the ignition switch in RUN position and the IOD fuse installed.
- Set Condition: The BCM does not receive any messages form the Powertrain Control Module (PCM) for at least 18 seconds.
Possible Causes:
- Attempt To Communicate With The TCM
- Body Control Module
Testing
- Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, attempt to communicate with Transmission Control Module (TCM). If scan tool communicates with TCM, go to next step. If scan tool does not communicate with TCM, perform NO RESPONSE FROM TRANSMISSION CONTROL MODULE OR BUS +/- SIGNALS OPEN test.
- Turn ignition off. Using scan tool, clear DTCs. Turn ignition on and wait one minute. Using scan tool, retrieve DTCs. If EATX BUS COMMUNICATION FAILURE DTC resets, replace Body Control Module (BCM). See BODY CONTROL MODULE under REMOVAL & INSTALLATION. If EATX BUS COMMUNICATION FAILURE DTC does not reset, fault may be intermittent. Check related wiring and connectors for poor connections or damage to wiring harness. See WIRING DIAGRAMS . Repair any problems found as necessary. If no problems are found, check if any Technical Service Bulletins (TSBs) apply to vehicle. If no TSBs apply, test is complete.