Circuit/System Description
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The radio or the chime module generates the audible warning through the left speaker. The radio or the chime module receives audible warning requests via the serial data circuit from the instrument panel cluster (IPC) or the body control module (BCM).