The PAC RP4-GM31 interface allows for the seamless replacement of a factory radio in select General Motors vehicles equipped with 29-bit LAN radios. This innovative RadioPRO4 interface comes pre-loaded with amplifier retention and steering wheel control (SWC) software, navigation-based output signals, and other features designed to simplify aftermarket radio installation while retaining crucial factory functionalities.

Key features retained include steering wheel controls, safety warning chimes, rear seat controls (RSC), and the factory BOSE amplifier. The RP4-GM31 also provides data bus driven outputs such as retained accessory power (RAP), vehicle speed sensor (VSS), illumination, reverse trigger, and parking brake. For vehicles with an overhead screen, the PAC GMRVD GM Rear Seat Video Retention Adapter (sold separately) is required to retain rear seat entertainment (RSE) functionality. The interface supports programming two radio functions to each SWC button using short press/long press dual command functionality and can be updated with new firmware via the PAC-UP interface updater (sold separately).