Circuit/System Description
WARNING: This page is about a different car, the 2008 Chevrolet Malibu Classic. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) monitors the instrument panel (I/P) lamps dimming control circuit to determine the lighting intensity of the I/P lamps. When the BCM receives a varied voltage signal on the I/P lamps dimming control circuit, it applies a corresponding pulse width modulated (PWM) voltage signal through the I/P lamps supply voltage circuit to all the I/P lamps.