Circuit/System Description
The driver window motor supplies 12V signal circuits to the driver window switch, when a window switch has been activated, a switch closes providing a ground to the appropriate signal circuit causing the voltage to drop to 0V. The driver window motor will detect the voltage drop in the signal circuit and will command the window to move in the desired direction.
The driver window master control switch also contains control switches for the passenger, left rear and right rear window functions. When a window switch is pressed, a serial data message is sent to the body control module (BCM). The BCM examines the request and checks for messages from other power window motors that may prohibit window movement. If no prohibitive messages have been received, the BCM will send a serial data message to the appropriate passenger or rear window switch which will perform the command as requested.