Diagnostic Aids
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.
Ensure all the stop lamps operate properly. Refer to Exterior Lighting Systems Description and Operation to avoid misdiagnosis. If the vehicle stop lamps operate improperly, refer to Symptoms - Lighting .