Transponder Immobilizer System

A “transponder system”, is a factory installed antitheft system that utilizes RFID technology to “immobilize” a car.  The ignition key in a transponder system is referred to as a transponder key

Why is it Called a Transponder System?

A transponder is a component of an RFID system, which is the basis of almost all modern OEM immobilizer systems.  The transponder is housed in the transponder key and stores a unique alphanumeric code needed to start a vehicle.  Since the transponder key is the most commonly serviced part of the system, the RFID derived immobilizer system naturally took on the name transponder system.

*The transponder microchip is also referred to as a “pellet” or “chip

What Does RFID Stand for?

RFID stands for Radio Frequency Identification.

Transponder System Operation

When the transponder key is inserted into the ignition lock an electro magnetic field emitted by the antenna ring  powers up the transponder located in the transponder key. The transponder then sends a alpha numeric code back to the vehicle.  If the alpha numeric code matches a previously stored code, the vehicle will start.

This is a very general description on how a transponder system operates.  No two systems operate the same.  Different manufactures use proprietary methods for validating the alphanumeric code stored in the transponder key.