Charge Indicator

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The instrument panel cluster (IPC) illuminates the battery indicator in the message center when the following occurs:

The engine control module (ECM) detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the ECM requesting illumination.
The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
The ignition is ON, with the engine OFF.

The IPC sends a class 2 message to the radio for audible warning when this indicator is on.