Circuit/System Description
WARNING: This page is about a different car, the 2016 Chevrolet Trax and 2016 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
The rearview camera is always supplied power when the vehicle is ON. Video signals are constantly to the Radio. If the Radio does not see a signal from the camera it will set B127B 2B and display "Service Rear Vision System".