A transponder key is a key like device that transmits a signal via radio waves, the signal is picked up by a receiver which in turn can start a car, unlock the car doors or open a gate. To reduce the possibility of unauthorized entry or use, each transponder key is programmed to start only one vehicle. Although transponder keys are known to reduce car theft, they are not foolproof.
The technology:
Although transponder keys have been around for some time, they did not begin to be used in vehicles until the mid 1990s. The transmitter component consists of a micro-chip which is imbedded in the plastic part of the key, every microchip has a unique serial number; this was set when the key was first programmed. When the possessor of the key wants to enter or start the vehicle, the microchip sends the request via radio signals to the receiver mounted in the car, the receiver responds to instructions and turns off the engine immobilizers. If the receiver and the transmitter cannot hand shake then the car will stay locked and immobilized. A key which has not been programmed will not be able to start the car, although the engine will turn over.
Transponders, although available for most cars, are more often found in new, high-end models. Cars can be fitted as an afterthought but it may prove to be costly as the car electronics may have to be reprogrammed and a new key will have to be produced. There are some locksmiths who can do this but often it is the car dealer who is best suited for the job.
Advantages and disadvantages:
The technology employed in transponder systems have led auto manufacturers and insurers to believe that a car so fitted is virtually theft-proof. Although it is certainly a deterrent, there is ample reason to believe that this is not so, that dedicated car thieves can and are getting around it, they simply tow away the car or they use a bypass machine.
It is considered wise to always have two transponder keys since replacement transponder key blanks are expensive. Once an owner gets new transponder key blanks, there are instructions on the internet that will allow him to program the key himself, if this fails, the manufacturer may provide programming instructions.
