Transponders, VAT Keys, and Vehicle Security


Where there are automobiles, there are instances of automobile theft. In the United States alone, a motor vehicle is stolen every 26.4 seconds. Vehicle manufacturers have gone to great lengths to make their vehicles difficult to steal; and most of these “great lengths” are now standard features for most vehicles made today.

Stealing the contents of a car may be a a motive for breaking into a car (from time to time), but most car thieves want to steal the vehicle itself. Although joyriding is often the ultimate goal of teenage car thieves, delivering the vehicle to a “chop-shop” results in profitable returns for all criminal elements involved. Significant monetary incentives for criminals has created a serious car theft problem. Car manufacturers have developed lock systems to thwart or otherwise hinder car theft.

           The Immobilizer
Starting around 2000, car manufacturers started equipping vehicles with immobilizers. An immobilizer is a device that immobilizes the car if an unauthorized key is used to start the vehicle. When the ignition is turned, the immobilizer sends a signal to the key; if the key does not return the proper signal back to the immobilizer, the device turns the ignition off, regardless of the key position.

The Transponder
How does the immobilizer communicate with the key? The immobilzer doesn’t communicate with the key; it communicates with a chip that is inside the key head. This chip is called a transponder. That plastic head on the key may only serve as a handy thing with which to hold onto the key, but more than likely it contains a transponder chip.

  Vehicle Remote Controls
If your key has buttons on it for locking and unlocking doors, starting the car, opening the trunk, etc., this is NOT a transponder. Although the key may (and probably does) ALSO have a transponder chip within the head, the “remote” itself is not a transponder.

 Programming Transponder Keys
After we make a key for your vehicle, we will program the transponder chip, if your key contains one. To be accurate: the chip itself is not programmed; your car is programmed to accept the new chip. This is done using a transponder programmer. This computer plugs into a terminal underneath your dash. The technician operates this computer until a “key in memory” (or related message) is given; programming is complete at this point. Programming often requires specific PIN codes or manufacturer PIN codes; sometimes the verifiaction process may take awhile.

  VAT Keys
In the 90’s GM started implementing an earlier version of the transponder, called VAT (vehicle anti theft). VAT keys come in 15 preprogrammed frequencies. Only 1 specific frequency can be used with a certain vehicle. A different type of device, a VAT reader, is required in order to determine the vehicle’s frequency in order to determine the proper key blank.