PAC Radio Replacement Interface for Select GÇÖ06-GÇÖ17 29-bit LAN GM Vehicles without On-StarThe PAC Radio Replacement Interface is a dedicated adapter that enables the installation of an aftermarket radio in select GM vehicles from 2006 to 2017 that do not have On Star. It interfaces with the vehicles 29 bit LAN network to ensure proper communication between the new head unit and the cars systems. Compatibility: Select GM vehicles from 20062017 without On Star. Technology: 29 bit LAN GM vehicle network interface for radio replacement.