Circuit/System Description
WARNING: This page is about a different car, the 2011 GMC Acadia, 2011 Chevrolet Traverse, and 2011 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The internal fault detection is handled inside the control module. The symptom byte listed in the DTC Descriptor is for engineering reference only. No external circuit diagnosis is involved.