Circuit/System Description
WARNING: This page is about a different car, the 2012 Buick Verano. However, it is still accessible from the selected car via links, so may be relevant.
Some control modules must be programmed with software that specifically identifies the correct type and quantity of modules on the serial data bus based on RPO configuration. If a control module was not properly configured after installation, the appropriate U Code may be set for that module. No external circuit diagnosis is involved.