What is a transponder (Chip) car key?
If you have lost your car keys or went to get a copy made in the last few years chances are you were shocked at the price. Gone are the days of copies of your keys for few pounds. As an automotive locksmith many people ask me, “What is a chip key?” To help prevent vehicle theft, most car manufactures’ rely on a system that was designed during WWII. To help prevent friendly fire incidents against Allied Aircraft a new invention was created. A transponder system would “transmit” a signal to an aircraft. The aircrafts system would then see the signal and “respond” with a corresponding code, giving us the word transponder. The use of computers and microchips in vehicles allowed this basic design to be compressed into your car keys and vehicle anti-theft system computer.
A simplified explanation of the system is as follows. Located around the mechanical key hole of your ignition there is an antenna coil. When the key is turned on the coil becomes energized and creates a small magnetic field. This magnetic field in turn energizes a small transponder chip embedded in the plastic head of your key. The chip emits a signal to the antenna ring which the carries the information to the cars computer. If the signal contains the proper coding, it allows the car to start. The coding on earlier models was very basic, newer models can carry an 80 bit alpha numeric code. The mathematical odds of a random matching code are well into the millions. On some recent models this amount of information allows you to limit the speed your child may drive your car with a specific key or even control how loud the radio can go. Also if your keys are lost or stolen, the lost key can be erased from your cars system without expensive mechanical re-keying. Of course all of this technology costs money. The proper tools, training and key blanks are all required to make a key properly.
When choosing a locksmith ask lots of questions and check them out thoroughly. Also, beware of on-line gimmicks selling discount keys. There are many on-line companies selling phony unusable keys and remotes much cheaper then maybe you were quoted. The old adage, ‘If it sounds too good to be true it probably is.’ should be adhered to. Push to start cars operate on the same principle and basically rely totally on the transponder portion of the key to prevent a theft. The next generations of keys are already making an appearance. The newest keys combine remote functions, transponder technology and a laser cut high security mechanical key.