HVAC Control Module: Notes

The HVAC control module is a non-GMLAN device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The battery positive and ignition 3 voltage circuits provide power to the control module. The control head displays recirc, outside air, A/C and rear defrost feedback status through LED indicators. The scan tool will display NO COMMUNICATION at the control module when checking DTCs or doing a vehicle diagnostic system check refer to Diagnostic Trouble Code (DTC) List - Vehicle and Diagnostic System Check - Vehicle in Vehicle DTC Information. The control module supports the following features: