ATC Module Messages Not Received
- Turn ignition on. Using scan tool, select BODY then AUTOMATIC TEMP CONTROL. If scan tool communicates with ATC, go to next step. If scan tool does not communicate with ATC, go to BUS +/- SIGNALS OPEN OR NO RESPONSE FROM HVAC .
- Using scan tool, erase DTCs. Turn ignition off and on. Wait a minimum of one minute. Using scan tool, check for DTCs. If DTC resets, replace Body Control Module (BCM). See BODY CONTROL MODULE under REMOVAL & INSTALLATION. If DTC does not reset, testing is complete.