Circuit/System Verification
WARNING: This page is about a different car, the 2009 Saturn Outlook, 2009 GMC Acadia, 2009 Chevrolet Traverse, and 2009 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
Ignition ON, command the Rear Red LED, Rear Yellow LED 1, and Rear Yellow LED 2 ON and OFF with a scan tool. The appropriate indicator should turn on and off as commanded.