Memory Seat Module
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 memory seat module (MSM) monitors the heated cooled seat switches through serial data message inputs and determines the heated cooled seat operating modes and temperature levels. The MSM controls the operating mode of the driver and passenger seats through separate pulse width modulation (PWM) signal circuits. The heated/cooled seat mode signal circuits are referenced from battery voltage by the ventilation heating and cooling modules and pulsed low by the MSM. Each heated cooled seat is capable of operating in 3 modes with 3 temperature levels so the MSM uses 9 PWM frequencies for each signal circuit to command the heated cooled seat modes to the seat heating and cooling modules.