Circuit Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The ambient light sensor indicates the light level to control the automatic headlamps and park lamps. The body control module (BCM) provides a 5-volt reference signal to the light sensor through the ambient light sensor signal circuit. The BCM receives the modified voltage from the ambient light sensor through the ambient light sensor low reference circuit. A low voltage under 1.5 volts, signals a dark condition to the BCM and vice versa.