Circuit/System Verification
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
Ignition ON, observe the scan tool SWC Bank 2 status while pressing and releasing the switches. The reading should be SW1-SW8 identifying the switch pressed, and Idle when released.