ATC Messages Not Received

Monitored & Set Condition

1. When Monitored: With the ignition in RUN position and the IOD fuse installed.
2. Set Condition: The BCM does not receive any messages from the Automatic Temperature Control (ATC) module for at least 18 seconds.

Possible Causes:

• Attempt To Communicate With The Automatic Temperature Control Module
• Body Control Module

Testing

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Using scan tool, select BODY, then AUTOMATIC TEMP CONTROL. If scan tool communicates with Automatic Temperature Control (ATC) module, go to next step. If scan tool does not communicate with ATC module, perform BUS +/- SIGNALS OPEN OR NO RESPONSE FROM AUTOMATIC TEMPERATURE CONTROL MODULE  test.
2. Turn ignition off. Using scan tool, clear DTCs. Turn ignition on and wait one minute. Using scan tool, retrieve DTCs. If ATC MESSAGES NOT RECEIVED DTC resets, replace Body Control Module (BCM). See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. If ATC MESSAGES NOT RECEIVED 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.