Car Transponder Keys


What is a Transponder Car Key?


Transponder keys are unique electronic keys and part of a car’s anti-theft system. The term transponder is derived by shortening the words: Transmitter and Responder. These unique keys have a small microchip embedded within the plastic head of the key that receives a signal from the vehicle that’s sent from a small antennae ring situated around the vehicle’s ignition cylinder. These electronic chips have non-volatile memory, a type of memory that doesn’t need constant energy to operate.


These keys use a system known as the magnetic coupled transponder system, which is passive in nature and operates at a frequency range of 125 kHz. As such, car transponder keys are quite limited when it comes to communication range. They have to be no more than 15 cm away (there are some that have longer ranges) from a vehicle for them to operate. For the vehicle to operate, a user has to have the key near the vehicle so that the vehicle’s onboard computer can receive a signal from it. Once the computer receives the proper signal, it deactivates the engine immobilizer, allowing the person with the key to start and operate it.


Benefits of Transponder Keys


Each transponder key is configured with a unique set of special codes. It is these codes that a vehicle interprets and determines whether the key is the right one. If the codes match those that the vehicle’s onboard computer is configured to, the computer activates the car. As such, it is impossible to ignite or even operate a car with a key that doesn’t have a valid code.


Another benefit of transponder keys is that they can be used to perform specific functions from short distances. For instance, with a transponder key, one can lock or unlock a car’s doors by the simple press of a button. At the same time, since these keys are part of a vehicle’s anti-theft system, they are integrated to the vehicle security system. As a result, once the car is locked and it detects any unauthorized access, it sounds an alarm, notifying the owner immediately.


Why Transponder Keys Are More Expensive To Replace Than Traditional Car Keys


As transponder keys are electronically coded, replacing one can be quite hectic. Initially, it was almost impossible to have one replaced, and the only way to get a replacement key was to contact your vehicle’s manufacturer or the dealership that sold you the vehicle – and this was quite expensive. To this day, getting a transponder key replacement from a dealership/manufacturer could cost you more than $1,000. However, as technology has advanced, it is now easier to have an extra copy created by a locksmith in the event you misplace or lose your original.


While approaching a locksmith is much cheaper, the cost is still quite high. This is because each car’s transponder key has its own unique codes assigned to it, and to have it replaced, there are things, like coding and programming, that will need to be done – and this process can be quite complicated and time consuming, especially when compared to the time and effort required to reproduce a standard key.


Considering the intricate nature of this task, it is easy to see why replacing transponder keys is costlier than replacing traditional car keys. Transponder key replacement costs range from $25 to $500 – or even more depending on the make and model of your car, and if you lost the only key you had.


If you misplaced the only key you had and need it replaced, you will probably be required to provide information regarding your vehicle’s make, model, year, and its VIN. With this information, a professional, experienced, and licensed locksmith should be able to cut and program an extra set of transponder keys that are unique to your car, helping to get your car up and running and you back on the road.

About the Author

William Sheridan with Best Home Security provides answers and solutions for all your home security needs. Visit for on-topic and useful information that can help keep your family safe.

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