Transponder keys make locking your car extremely easier then what it used to be like. Without transponder  keys ,  you have to go to your car and unlock and lock it yourself, well with a transponder key all you have to do is press a b u tton and your keys are locked.    The way these keys are designed to transmit a radio signal from a handheld device to a remote receiver. Transponder keys are used to unlock and start  vehicles and  have also been used to  open gates and are used in buildings for   keyless entry systems .    Each one is programmed to start a specific vehicle, gate or whatever you need to use one for.  These also help reduce the possibility of theft. There  is   a  number  of ways to bypass transponders, some of this can be done with inexpensive equipment.    The majority   of  newer cars come  with a transponder  key  because the technology was first int...