Sierra 3500 4WD V8-6.6L DSL Turbo VIN 2 (2004)
Control Module HVAC: Description and Operation
HVAC System - Manual
HVAC CONTROL MODULE
The HVAC control module 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 control module supports the above features.
The HVAC control module 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 used 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 control module supports the above features.