With RPO UM8
WARNING: This page is about a different car, the 2007 Isuzu Ascender, 2007 GMC Envoy, 2007 Chevrolet TrailBlazer, and 2007 Buick Rainier. However, it is still accessible from the selected car via links, so may be relevant.
If the navigation radio is replaced and a theft locked condition exists, the following procedure must be performed:
Perform the Radio Setup (With RPO UM8) .