Pac C2R-GM24 Radio Replacement Interface C2RGM24 For most 2001-2003 GM SUV's and trucks. Retains warning chimes when replacing factory radio in vehicles without OnStar®. Retains all warning chimes including back-up chimes, memory seats, low fuel, door/hatch ajar and others. Provides a +12volt accessory wire. Retains RAP (Retained Accessory Power) when key is turned off. Radio stays on until the door is opened or for aproximately 10 minutes. Supplied wire harness to connect aftermarket stereo to factory speakers. Will work in vehicle that have the factory Bose® amplifier removed or bypassed. Custom wiring is required. Buzzer is built into the interface. If the Bose® amplifier is not used/bypassed, you can use the C2R-GM24 to retain the warning chimes. Vehicles supported: 2000-2003 Cavalier, Impala, Monte Carlo and Trail Blazer-non-Bose® 2002-2003 Malibu 2002-2003 Envoy SLE-not SLT 2001-2003 Montana and Venture 2003 Avalanche, Express, Silverado, Suburban, Tahoe, Savana, Sierra-not Denali, Yukon SLT and Bravada 2004 Grand Prix GTP Vehicles not support with exception of note: 2003 Hummer H2, Cadillac Escalade and all Denali's 2002-2003 Envoy SLT