Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) uses a varying voltage signal from the IP dimmer switch in order to determine the rate of pulse width modulation of the control circuit of the illumination lamps. The pulse width modulation rate determines the brightness of the illumination lamps.