Circuit/System Description
WARNING: This page is about a different car, the 2008 Pontiac G8. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) illuminates the antilock brake system (ABS) indicator during the IPC bulb check or when the electronic brake control module (EBCM) detects a fault and sends a serial data message to the IPC commanding the indicator ON.