Circuit Description
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 instrument panel cluster (IPC) has an internal voltage sensor with a dedicated circuit that monitors the battery positive voltage circuit to determine if it is below 18 volts.