Circuit/System Description
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.
The trailer brake relay control circuit high SSR enable circuit short to battery monitors for short-to-high faults on the trailer brake solid state relay (SSR) enable circuit. In general, the SSR enable short-to-high circuit diagnostic is executed whenever the SSR has been disabled for a minimum duration. Typically, the diagnosis is executed at TBCM power up. The diagnosis test passes, if TBCM detected the status is correct for consecutive 16 samples.