Circuit/System Description
WARNING: This page is about a different car, the 2010 GMC Terrain and 2010 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The radio communicates with the radio/HVAC control via serial data. This DTC indicates a fault in the radio/HVAC control. No external circuits are involved. The radio may continue to respond normally to faceplate functions when this DTC is set.