Circuit/System Description
WARNING: This page is about a different car, the 2013 Cadillac XTS. However, it is still accessible from the selected car via links, so may be relevant.
Some devices must be programmed with software that specifically identifies the correct type and quantity of devices on the serial data bus based on RPO configuration. If a device was not properly configured after installation, the appropriate U Code may be set for that device. No external circuit diagnosis is involved.