Courtesy Lamps Manual Operation
WARNING: This page is about a different car, the 2007 Pontiac Montana SV6, 2007 Chevrolet Uplander, and 2007 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
The courtesy lamps, may be manually operated by the I/P dimmer switch. When the I/P dimmer switch is placed in the ON position, the BCM receives a ground signal from the courtesy lamps ON switch signal circuit. Upon receiving the courtesy lamp switch signal, the BCM then applies battery positive voltage to the courtesy lamp high control circuit, which illuminates the courtesy lamps. The interior lamp switch will override any BCM operation of the interior lamps, such as entry illumination.