What is Car Transponder Key?

02-04-2021 -

What is transponder key?

Almost every motor vehicle on the road today has been provided with some kind of electronic transponder key. This include manufacturers such as Hyundai, Chevrolet, Toyota, Chrysler, Kia and Honda. In simple terms transponder keys is a key which has been fitted with a small transmitter altogether with a small receiver placed in the vehicle, close to the ignition switch, which is able to receive a signal transmitted by the key. This is a low-level RF signal with a specific code which can only be detected by the receiver when the transponder key is in the ignition switch. This system is used by manufacturers to make it very difficult for the vehicle to be hotwired. Such a motor vehicle will not start and even locked itself if the receiver does not detect the signal which is transmitted by the transponder key.

How do I know if my key has a transponder chip?

There are three main alternative to check if your key has a transponder chip:

1. Open this link and search your car make, model and year and check the results.
2. In most cases, the key plastic head will be a little wider than a key with no chip. Another test is to wrap the plastic part of the key with a few foil layers and then try to start the car. If it don’t start, there is a chip present.
3. Another way to know that you have a transponder key is by it’s price. Call your dealer-ship with your vehicle identification number and request for a key replacement cost. If the price is a few buck, chances are strong that it is not a transponder key. If the price above $50, it is most likely that a transponder is present!

Note: There are few exceptions, however they are rare.

How to duplicate transponder key?

To duplicate a transponder key not only the key blade need to be cut, but the key has to be programmed with the proper signal. An attempt to use an un-programmed key on the motor vehicle, will simply fail with probably warning/security lights on because the correct signal has not been received from the transponder.

Lost transponder key - What to do?

In the past losing a key to your vehicle had a pretty simple solution. All you had to do was drive to the dealership with your VIN and the dealer would contact the auto maker to get the key code to be able to cut a new key. However with immobilized vehicle, this key cutting by VIN will not be sufficient, since the chip need to be programmed to sync with the vehicle ECU for the car to start. This means that you have to tow the vehicle to the dealer or call a mobile locksmith to come out to your location to reprogram the vehicle to accept the new key and reject the old one. This is a mandatory security measurement that comes from the car manufacture to make sure that if someone will find the old lost/stolen key, he will not be able to start the vehicle.

References

1. Wikipedia - Transponder
2. Wikipedia – Immobiliser.

Related articles/services

1. Car key replacement
2. Ignition repair
3. Automotive locksmith