Diagnostic Aids

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

The radio and window RAP function are separate RAP functions controlled by serial data and the specific module. These functions are not effected by the BCM RAP relay circuits.
A short to ground or open/high resistance in the RAP relay switched voltage circuits will cause only part of the RAP functions to be inoperative. Diagnose these symptoms within the respective system sections.
A short to voltage on the RAP relay control or switched voltage circuits would cause the RAP function to remain on past the designated time.
A stuck relay switch could cause a RAP always on, or a RAP inoperative condition.