Revolar is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

What is a Transponder Key? How Does It Work?

Fact checked by Teddy B.Miller

what is a transponder key

Do you ever wonder why your key is different from other keys and has a plastic shell on its head? You might have a transponder key that can access your car.

What is the transponder key’s definition? This key has built-in microchips on its handle, emitting signals to the car’s receiver. This unique signal will be the only signal the car will recognize and give access to.

Now that we know the answer to the question “what is a transponder key?,” let’s dive deep into how it works.

A Vehicle Transponder Key


The transponder key is a relatively new invention, appearing in contemporary car models. They are intended to serve as a deterrent to car thieves.

Its technology sends a low-level signal from the key to the car’s receiver, often near the ignition. Indeed, each key includes a unique serial number that allows users to open the car. Transponder keys are also utilized for automatic garage and gate doors. 

1. What does a transponder key do?


It opens the lock manually by inserting it into the car door lock. It also serves as the key for the ignition, which the car will only respond to. That way, the thief cannot manipulate the ignition switch to turn on, even with force.

2. How does a transponder key work?


The secret lies within what is inside the plastic shell on the key’s handle. As stated above, transponder keys have built-in microchips that transmit signals from the key to the car’s signal receiver.

That is why if the ignition key transponder detector doesn’t recognize any nearby transponders that correspond to the car, the car will not turn on. This means the car cannot be hotwired or accessed by any other keys except its transponder key.

3. Types of transponder key


Basic transponder keys started with just being a key with a built-in chip. However, it branched out to different types to accommodate different needs.

The following are four types of car key transponder chip:

  • Regular transponder key – This type of transponder key is usually used to access older models of cars.
  • Remote head key – Also known as the remote flip key, the remote head key is a crucial transponder and remote key turned into a single key.
  • Fobik chip key – This type of key comes as a remote with a built-in metal blade to access the car door lock for emergency purposes.
  • Proximity key – Also known as a comfort access key, this type of key is a smart key designed with push buttons for easy and convenient access to your car.

4. Pros and cons of a transponder key

Having chip keys for cars can have its ups and downs. The followings are the pros and cons of having a transponder key:

  • Transponder keys cannot be easily duplicated
  • The car will not start if the transponder key isn’t nearby
  • Excellent protection against car thieves
  • Transponder keys last more than traditional keys
  • Requires to be programmed when starting
  • Expensive to reprogram and replace 

5. Cost of a transponder key


A transponder key replacement can range from $200 to $250, depending on the make and model of your car. This is more expensive than having your key fob or remote key replaced.

How to Program Transponder Keys


Before you are allowed to program a transponder chip key by your locksmith or car dealership, you need to have proof of ownership first. To program transponder keys, follow these steps:

1. Get your key inside the ignition of the car. Then, turn the key into the on position.

Note: the engine shouldn’t be turned on, only the electronics.

2. Wait for 10 and a half minutes.

3. Turn off the car by putting the key in off position.

4. Turn the key again to turn on the electronics but not the engine.

5. Again, wait for 10 and a half minutes.

6. Turn off the car again by putting the key in off position.

7. Repeat steps 5 to 7.

8. For the last time, turn the key into one position. This step will have your key programmed.

9. Test the newly programmed key.

Transponder Key vs Remote Key vs a Fob: What is the Difference?

A remote key, or also known as a key fob, works with two levels of security — one, the remote key can be manually inserted into the car’s door lock to access the car, and two, the remote key utilizes radio frequency to send signals to the car.

On the other hand, a transponder key can do both levels and another layer of security — the car cannot start if the transponder key cannot be recognized by the car if it is put inside the ignition.

Frequently Asked Questions


Where to get transponder keys manufactured?

Initially, vehicle transponder keys are manufactured in the offices of your car makers. However, locksmiths and some dealerships can provide you a spare transponder key for your car.

Note: having a transponder key programmed might not be simple for everyone since it takes skill and special equipment to get it done.

How do I know if my car key is a transponder key?

It might be challenging to identify a transponder key since they almost look like other types of keys. Here are some of the ways you can tell if your car key is a transponder key:

  • Consult the locksmith database.

Some locksmiths have a database of vehicles and the corresponding transponder key information, which will help you identify your key. You can also access the list of cars with transponder keys.

  • Look for the security light.

A security light is commonly found on your car’s center console or dashboard for vehicles that can be accessed through a transponder key. The security light should have a picture of a lock, a key, or just a small light.

  • Check your key.

A transponder key for a car has a chip inside its plastic head, which is why they are generally bigger than most keys. Also, identifying your car’s make, model, and manufacture year can give you the identity of your key.

  • Bring your key for testing.

Some locksmiths or manufacturers can identify your key for you as long as you bring it with you when you go to their offices or factories.

How much does it cost to program a transponder key?

If you send your transponder key to a locksmith to program it, it costs you $50 to $250. It might cost less if you provide a transponder key blank to be programmed for your car, depending on the locksmith.

How long do transponder keys last?

Since transponder keys do not have batteries that power up the transponder, transponder keys usually last as long as the lifetime of your car. However, this excludes external circumstances, such as getting your transponder key broken.


Learning more about your car goes a long way. It updates your knowledge about your car, and you can also share it with other people who want to learn more about their cars.

The next time someone asks you “what is a transponder key?”, you already know the answer and more. Share this knowledge of the transponder key meaning and purposes with your car-buff friends so they will enjoy reading this, too!

5/5 - (2 votes)