What Are Transponder Keys, and How Do They Work?

The transponder (a portmanteau for transmitter and responder) has been a common component of car keys since the mid 1990s. They were developed as a response to increasing levels of car theft, as every transponder gives cars a unique code needed to start the ignition.

But what exactly is a transponder, and how does a car key transponder work?

Here’s an overview of what you should know about transponder keys for vehicles.

About transponder keys

A transponder is a type of electronic whip with a wire coil that runs around it for the purpose of receiving and transmitting electromagnetic signals. The chip acts similarly to the memory storage in a phone or computer—it doesn’t need constant power to hold memory.

Car keys use a specific type of transponder referred to as a magnetic coupled transponder system. These systems do not have their own power source, and they operate in radio frequency, allowing them to penetrate rubber and plastic (which is why it’s placed inside the key bow). Transponders have a range of only around 15 cm, due to them not having their own power source.

The key functions with the assistance of an induction coil that also gets fitted around the ignition barrel in the car. When a key with a transponder is put into the barrel and turned on, the coil sends a pulse of electromagnetic energy that gets absorbed by the wire coil that runs around the transponder chip. Once absorbed, the energy powers the chip and causes it to send a signal containing the identification code of the key.

That signal then goes to the induction coil, where the system reads the code. If the codes match with the on-board computer in the vehicle, this allows the car to start up. All of this happens nearly instantly. Some transponder systems will also include cryptographic codes to prevent the code from being copied from the onboard computer in a vehicle, providing an even greater level of security.

If you need a replacement transponder for your vehicle, it is crucial that you get one from a reliable source. You can get them from the vehicle’s manufacturer or from various manufacturer-approved sources, but avoid purchasing them directly from other people or sites like Craigslist—you’ll want to be sure you can trust the security and functionality of any transponder you purchase.

That is all of the basic information about what a transponder key is and how it functions. If you’re interested in learning more about some of the basics of the transponder key option and what it is about transponders that improves vehicle security and safety, we encourage you to contact us today at Toledo Lock & Key LLC with any questions you have for our team.

Our locksmiths are experienced in working with vehicle keys of all types. If you’re having any issues with the operation of your transponder key, we’d be glad to take a look and identify and resolve the problem. Reach out to learn more!

Categorised in: Transponder Key

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