Circuit Description
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The voltage level is monitored by the Dash Integration Module (DIM) and is sent as a Class 2 data message to the Instrument Panel Cluster (IPC). If the DIM looses power the IPC will default to the last voltage level.