Circuit/System Description

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The body control module (BCM) applies battery voltage to the courtesy lamps through 2 separately controlled courtesy lamp supply voltage circuits. When any door is opened, the door ajar switch contacts close and the BCM receives a door-ajar input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamp supply voltage circuits, providing battery voltage to all of the instrument panel (I/P) courtesy lamps, dome lamps, rearview mirror lamps, and rear compartment lamps. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp control circuits to prevent a total battery discharge condition.