A transponder key has a chip inside that is programmed specifically to your car. This allows your car and key to communicate through radio transmission, in most cases. The key sends a signal to an immobilizer that is fitted into your vehicle which decides whether your engine will turn on or off. What this means is that only you can start your car as long as you have that transponder key. It’s an incredibly reliable way to ensure that your car is theft-proof.
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