Display Dimming
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Display dimming is controlled by the BCM based on input received from the dimming potentiometer. The dimming potentiometer is connected between circuit 230 and circuit 470. The BCM monitors their inputs and provides a pulse width modulated (PWM) output at circuit 8 to operate the display lamps.