Transponder key is an automotive security device that uses radio frequency identification (RFID) technology to communicate with a vehicle's immobiliser system, enabling engine start only when the correct key is present. Embedded with a microchip, each key is programmed with a unique code that must match the vehicle’s system to deactivate the immobilization mechanism. This advanced feature significantly reduces the risk of car theft, as duplication of the key requires not only the physical replication but also the reprogramming of the chip’s code.
Upon insertion into the ignition switch, the key transmits a low-level signal to the vehicle’s control unit, which must recognise the code for the engine to start. If the transmitted code does not match the one stored in the vehicle’s system, the engine will remain immobilised. These keys are now standard in most modern vehicles, reflecting a shift towards enhanced vehicle security protocols. The use of such keys also facilitates the integration of additional features such as remote locking and unlocking, panic buttons, and boot opening, further improving user convenience and safety.