GM Service Manual Online
For 1990-2009 cars only

Power Window Initialization

The window initialization procedure will need to be performed any time the battery is disconnected. the procedure allows the RDM to detect the top and bottom position of the window glass and to calculate actual window position in relation to the top and bottom. The RDM shall store these end positions once they have been detected when the window has reached the full up and full down positions. It is not possible to initialize the window if the door is open, because the window glass needs to seat in the weather-strip on the roof. If the door is open and the initialization is lost due to battery disconnect, the actual position of the glass after power is switched ON again will become the Zero-position, and if the RDM receives a door open status the glass shall index down.

To perform the window initialization procedure:

  1. Close the vehicle doors.
  2. Activate the window switch in the up position until the window has reached the full up position and stalls and hold the switch for an additional 0.5 seconds.
  3. Activate the window switch in the down position until the window has reached the full down position and stalls and hold the switch for an additional 0.5 seconds.