Power Window Operation

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

The driver and front passenger doors are equipped with power window motors that contains its own module. Each power window motor receives a hot at all times battery supply voltage and constant ground source. When the right front passenger window switch on the DDS is activated to the up or down position, the DDM will interpret the signal and send a GMLAN serial data message to the PDM. Upon receipt of the message, the PDM will send a signal to the front passenger window motor module on the GMLIN serial data circuit. The window motor module will then supply battery voltage and ground to the window motor to drive the window motor to the up or down position.

The DDM communicates via the GMLAN serial data circuit with the body control module (BCM) to control the rear window functions from the driver master window switch. The BCM is hard wired to each rear power window switch with circuits for window up, window down, and an enable circuit. The rear window switches contain internal logic that when supplied with voltage from the BCM over the enable circuit will driver the appropriate window in the direction commanded.

The rear power window switches are supplied with battery voltage from individual right and left WNDW fuses located in the rear fuse block. When a rear power window switch is activated to the DOWN position, voltage is applied to the motor down circuit and the motor up circuit serves as the path to ground. The window motor will drive in the downward direction until the switch is released or the window has fully opened. When the window switch is activated to the UP position, voltage is applied to the motor up circuit and the motor down circuit serves as the path to ground. Ground for the left rear power window switch is supplied at G200 and the right rear power window switch receives ground at G201.