Circuit/System Verification
WARNING: This page is about a different car, the 2017 GMC Yukon XL, 2017 GMC Yukon, 2017 Chevrolet Tahoe, and 2017 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
Key ON, engine OFF. The TCCM runs a 2 second bulb test on all indicators of the TCSCS at key ON.