GM Service Manual Online
For 1990-2009 cars only

Power Windows System Components

The power window system consists of the following components:

    • Door lock/window switch
    • Left rear window switch
    • Right rear window switch
    • Window motors in each of the doors
    • WNDW CTRL 2A Fuse
    • WNDW MTR 20A Circuit Breaker

Power Windows System Controls

The power windows system can be controlled by pressing or pulling the appropriate power window switch.

Front Window Operation

Voltage is supplied to the door lock/window switch through the ignition voltage supply circuit. The front window motors are supplied B+ voltage and have a continuous ground circuit. When the left front or right front switch is placed in the up or down position, supply voltage is sent to the appropriate control circuit for the appropriate window motor. The window motor upon reciept of the voltage will command the window to move in the direction desired.

Express Up and Down Feature

The express up and express down features allow the operator to completely open or completely close the window without constantly holding the window switch. By pressing the window switch past the first detent and releasing, voltage is supplied to the window motor, the logic circuit within the window motor will command the window to roll completely down. Each window motor contains internal Hall affect sensors to monitor the travel of the window. When the appropriate window receives an express up command, the window motor will monitor the motion of the window and compare it with the learned travel extent and will automatically reverse the window travel if the window motor detects an obstruction before the window reaches the full up position.

Whenever B+ voltage is lost to any or all the window motors, the window motors must relearn the window travel extents before the express up and express down feature will function.

Lockout Switch Feature

The door lock/window switch contains a rear window lockout switch, which when closed, provides power to the rear window switches. If the window lockout switch is pressed, the contact of the window lockout switch opens interrupting the voltage to the rear window switches, disabling them. The rear power windows will operate still function normally from the door lock/window switch.

Rear Passenger Window Operation

The rear passenger power window switches receive voltage through the closed contact of the rear window lockout switch. When the rear window switch is placed in the up or down position, the contact within the window switch will allow supply voltage to be applied to the appropriate control circuit for the rear window motor. The window motor upon reciept of the voltage will command the window to move in the direction desired.

The rear passenger power windows can also be controlled from the driver power window switch.