Power Windows

Power Windows Description and Operation

Power Windows System Components

The power window system consists of the following components:

* Driver window switch
* Passenger window switch
* Window motors in each of the doors
* F26U 30A Fuse

Power Windows System Controls

The power windows system can be controlled by pressing or pulling the appropriate power window switch and may be commanded to raise or lower by the BCM through a serial data message to each of the window motors.

Driver Window Operation

The driver window switch receives a constant ground source and the driver window motor is supplied battery voltage through the accessory voltage supply circuit. The logic circuit within the window motor monitors the up, down and express signal circuits which are normally equal to B+ voltage. When the driver window switch is used, the contacts close causing a voltage drop within the appropriate signal circuit. The window motor will detect the voltage drop and will command the window to move in the direction requested.

Passenger Window Operation

The driver and passenger window switches each receives a constant ground source and the passenger window motor is supplied battery voltage through the accessory voltage supply circuit. The up, down and express signal circuits are shared between the right front switch on the driver window switch and the passenger window switch. The logic circuit within the window motor monitors the up, down and express signal circuits which are normally equal to B+ voltage. When the right front switch is used on the driver window switch or the passenger window switch is used, the contacts close causing a voltage drop within the appropriate signal circuit. The window motor will detect the voltage drop and will command the window to move in the direction requested.

Express Up/Express Down Feature

The logic circuit within the window motor monitors the express signal circuits which are normally equal to B+ voltage and when the appropriate switch is pressed or pulled past the first detent and released, the logic circuit within the window motor will command the window to automatically fully open or fully close depending upon which command was initially requested. The driver and passenger doors contain smart motors that will detect excessive resistance while performing the express up function and automatically reverse direction to prevent injury to any occupants that may become trapped between the closing window and the roof. The automatic reverse safety feature can be overridden by pulling and holding the window switch.