Circuit/System Description
WARNING: This page is about a different car, the 2015 GMC Terrain and 2015 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
This diagnostic applies to internal microprocessor integrity conditions within the device. This diagnostic also addresses if the device is not programmed. The device monitors its ability to read and write to the memory. It also monitors a timing function. No external circuits are involved.