Circuit Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) illuminates the ABS indicator by supplying ground to the lamp. The electronic brake control module (EBCM) sends class 2 serial data messages to the IPC in order to command the indicator ON or OFF.