HVAC Control Module
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The heated cooled seat system operation is controlled through the switch inputs of the HVAC control module. The heated cooled seat switches provide 3 inputs that are relayed to the Memory Seat Module (MSM) through GMLAN messages. Whenever one of the switches is pressed a message is sent to the MSM indicating switch is active. During heated cooled seat operation the HVAC control module displays the switch symbol of the active operating mode and the temperature level bars on the climate control display. The mode symbol and temperature bars that are displayed is determined by a GMLAN message from the MSM.