Circuit/System Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The driver and front passenger heated seats are controlled by the memory seat module (MSM). When active, power is applied to the seat cushion and seat back heater elements through a common voltage supply circuit. The module controls the seat temperature by providing a pulse width modulated (PWM) ground through the heated seat element control circuits to the seat heater elements. The module then monitors the current flow through the heating elements and the of rate change of the temperature sensors to verify correct heated seat operation.