Heated/Cooled Seat Switch and Door Lock/Window Switch (Chevrolet and GMC)

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The heated and cooled seat system is controlled through the heated and cooled seat switches that are located on the door panels. Ground is supplied to the heated/cool seat switch through the low reference circuit and the respective door module. The door module plays an important part of the climate control seat operation, first by relaying the selected switch inputs to the MSM, and second, by controlling the mode and temperature indicators of the heated/cool seat switch.

When either a heat or cool seat switch is pressed, ground is applied through the switch contacts and the switch signal circuit to the door lock/window switch. In response to this signal, the door lock/window switch sends a serial data message to the MSM indicating the switch input. In response to this message, the MSM sends a pulse width modulation (PWM) signal through the appropriate heated/cool seat mode signal circuit to the seat ventilation heating and cooling modules indicating the heated or cooled seat request. The door lock/window switch then applies a ground through the appropriate heat or cool seat indicator control circuit to the switch illuminating the selected heat or cool mode indicator. At the same time, the door lock/window switch also applies a ground through the appropriate high, medium, or low temperature indicator control circuits illuminating temperature mode indicators.