GM Service Manual Online
For 1990-2009 cars only

Power Windows System Components

The following components are used to control the power windows:

    • Roof door module (RDM)
    • Master power window switch
    • LH front power window motor
    • Driver power window motor with position sensors
    • Passenger power window motor with position sensors
    • Driver and passenger door handle switches
    • Driver and passenger door jamb switches
    • Driver and passenger lock switches
    • ROOF - DOOR MOD 30-amp circuit breaker
    • RDM2 15-amp fuse
    • IGN 0 10-amp fuse

Power Windows Controls

The vehicle is equipped with power windows controlled by the RDM. The driver and passenger power windows are controlled by either of the following:

    • A power window switch activation which sends a switched ground signal to the RDM indicating an up or down request
    • A window indexing function which is enabled in the up direction by lifting the door handle and enabled in the down direction when the door is closed
    • A moveable roof open request in which both power windows perform an express down function

Power Window Motor Operation

Each power window motor receives battery voltage and ground from the RDM through the window motor control circuits. The window motors are reversible. The direction the window moves depends on which motor control circuit the voltage is applied to, and which motor control circuit the ground is applied to. To move the window in the Up direction, the module applies voltage to the window motor Up control circuit, and ground to the window motor Down control circuit. When a window movement in the opposite direction is needed, the module reverses the polarity and applies voltage and ground to the opposite circuits to move the window in the reverse direction.

Both power window motors also have internal position sensors. These sensors signal the RDM with current window position data. They are supplied both battery voltage and a constant ground source and use two signal circuits to the RDM.

Power Window Express Down Operation

The express down feature is used to lower the driver and passenger power windows to the full down position when the either window switch is momentarily activated in the down direction or when a moveable roof open request is received.

Power Window Indexing Feature Operation

This feature is used to lower the driver and passenger power windows down approximately 9 mm when the door is opened . This is necessary to allow the top edge of the window to clear the window weather-strip. This feature will also raise the window to the fully seated position once the door is closed.

This feature is enabled in the down direction by a switched ground signal to the RDM from the door handle switch when it is lifted. The RDM will then supply power and ground to the appropriate window motor control circuits to lower the window.

This feature is enabled in the up direction by a switched ground signal to the RDM from the door jamb switch when the door is closed. The RDM will then supply power and ground to the appropriate window motor control circuits to raise the window.