Circuit/System Verification
WARNING: This page is about a different car, the 2013 GMC Acadia, 2013 Chevrolet Traverse, and 2013 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
Engine running, using a scan tool perform the VES Actuator test. Command the actuator while turning the steering wheel, the effort should increase when commanded between 10-100%.