HVAC Control Module

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The HVAC control assembly is a class 2 device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The battery positive voltage circuit provides power that the control module uses for Keep Alive Memory (KAM). If the battery positive voltage circuit loses power, all HVAC DTCs and settings will be erased from KAM. The Body Control Module (BCM), which is the vehicle mode master, provides a device on signal.

The HVAC control assembly is powered up by the ignition 3 voltage circuit. When the air temperature switch is rotated a variable resister in the HVAC control assembly changes the voltage on the air temperature door control circuit for an actuator position change. The module does not utilize Keep Alive Memory (KAM). The module does not have Class 2 communication, personalization and programming available.