PAC C2R-GM24 GM Chime and Data-Bus Integration Interface Gm chime and data-bus integration interface Enables aftermarket radio Installation without factory radio retention Replicates factory warning chime Provides a data-bus generated 12V accessory power output that is compatible with gm's retained accessory power (RAP) Issues data commands that maintain a "healthy" system status to other vehicle systems GM Chime and Data-Bus Integration Interface Enables aftermarket radio installation without factory radio retention Replicates factory warning chime Provides a data-bus generated 12-volt accessory power output that is compatible with GM's Retained Accessory Power (RAP) Issues data commands that maintain a normal system status to other vehicle systems