Circuit/System Verification
WARNING: This page is about a different car, the 2010 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
Install a 12 V DC accessory into a X80 accessory power receptacle. Ignition ON, command the Accessory/Retained Accessory Power Relay Command ON and OFF with a scan tool. The K10 accessory relay should click and the 12 V DC accessory should have power.