WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
A DTC B1477 sets when the BCM detects a short to ground in the RAP relay control feed circuit when it is trying to energize the RAP relay.
The condition above must be present for more than 0.3 seconds.