Circuit/System Verification

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON, clear the DTC. Observe the scan tool BCM Stop Lamp Relay Command parameter while pressing and releasing the brake pedal. The parameter should change between ON and OFF.

If the parameter does not change between the specified values, refer to Stop Lamps Malfunction .