I'm not sure if anyone can answer this one but when I bought the TGP there was an aftermarket GM alarm on the car that had GM Fob's (remote transmitters) programmed to go with it. I'm wondering if the Fob's will work with the stock system. I've tried them and they don't work but I'm not sure if it's the fob's or the system itself (I'm working on that issue) They are a newer style with 4 buttons and a centrally located LED that flashes when a button is pushed. The part number is 12495653. If they aren't going to work then I have 3 of these that I'm going to be looking into getting rid of if anyone is interested.