Originally Posted by AveoRob
There are different types of bypass modules. Some are universal and require a spare key with the transponder be placed in a box and that is how it is bypassed. Others are manufacturer / vehicle specific and they "learn" the data stream that needs to be sent by the transponder, and then sends that code when the remote start is activated. Some of these are usable in more than one type of GM and may be more expensive, but will be able to be used in another GM if you move the RS. First figure out if you need one. then get a vehicle specific, not a universal, as you are leaving the key in your vehicle..and a spare transponder key is like 50-75 bucks.