A transponder key is a car key with a small electronic chip in its head. When you turn the key, the car reads a code from that chip, and the engine starts only if the car recognizes the code. Transponder keys are common on today's cars, which is why a key that only matches the cuts can unlock your door and still fail to start the car.
How a transponder key works
The chip has no battery of its own. A coil around the ignition lock gives off a small electromagnetic field, and that field powers the chip long enough for it to send its code. The car's engine computer checks the code. If it does not recognize the key, it will not let fuel flow or the engine fire.
This system is called an immobilizer, and it exists to stop a car from being hot-wired. It also means every new key has two parts to get right: the blade has to fit your locks, and the chip has to be programmed to your car.
Signs the car is not recognizing your key
- The engine cranks but will not start, or it starts and then stalls.
- A key or security light flashes on the dash.
- A newly cut key turns in the ignition and opens the doors, but the engine will not start.
We fix this with key programming at the car. Programming a key you already have starts at $99 for most makes.
Transponder key, remote key, or smart key?
These names get used loosely, and one key can be more than one of them.
- A transponder key, or chip key, is a metal blade with a chip in the head. The chip is what lets the engine start.
- A remote key puts the blade and the lock, unlock, and trunk buttons in one piece, with the chip inside.
- A smart key, or proximity key, can stay in your pocket or bag while you start the car with a push button.
Each type is cut, programmed, or both in its own way, which is why we ask for the year, make, and model when you call.
What a new chip key costs
For most domestic, Japanese, and Korean makes, these are our starting prices:
| Job | Starting price |
|---|---|
| Regular car key, usually with a transponder chip | Starting at $129 |
| Remote key or key fob | Starting at $159 |
| Smart key (push-to-start) | Starting at $189 |
| Programming a key or fob you already have | Starting at $99 |
Some makes start higher, and our car key replacement cost guide lists every group. We confirm the final price on-site before any work begins.
How a new chip key is made
We come to where the car is parked, cut the new key to your locks, program its chip to your car, and test it before the job is finished. If every key is lost, we can make and program a new key from scratch, and our guide to lost car keys with no spare covers what to have ready.
When a key is lost or stolen, we can reset the immobilizer as an optional service. It removes previously lost or stolen keys and fobs from your vehicle's system, so they can no longer start the car.
How to tell whether your key has a chip
The chip sits in the plastic head, so a key with a plastic head may have one, though not every plastic-headed key does. The surest way to know is to call with the year, make, and model. You can also find your make on our brands page.
Need a new chip key in Atlanta?
Call (470) 668-2196 with the year, make, and model, and tell us whether any key still works. Have a photo ID and your registration, insurance card, title, or bill of sale ready. We work Tuesday through Sunday from 7 AM to 7 PM, Wednesday until 5 PM, and we are closed on Mondays, across Atlanta and more than 20 surrounding cities on our service area page.