Which key do you have?
- Plain metal key. A thin blade with teeth on the edges and a plain plastic or metal head. Mostly cars from before the late 1990s.
- Transponder (chip) key. It looks like a plain key with a thicker plastic head. Inside the head is a small chip the car reads when you turn the ignition. No chip the car recognizes, no start.
- Remote head key. Key and lock buttons in one piece. It has a chip for starting and a separate transmitter for the buttons, and both are programmed.
- Flip key. A remote head key whose blade folds away. Same parts, different shell.
- Smart key (push-to-start). A fob you keep in your pocket; the car detects it nearby and you press a button to start. It hides a small emergency blade inside for the door.
Blades come in two kinds as well: the ordinary edge-cut blade with teeth along the edges, and the laser-cut or sidewinder blade, thicker, with a wavy channel milled down the flat face. Both are cut on a code machine that reads the pattern from a key or a code.
Why a copied key opens the door but will not start the car
The door only checks the blade. The ignition checks the chip. A key copied at a hardware store without a chip, or with a chip that was never programmed to your car, turns in the door and the ignition and the engine still refuses, because the immobilizer does not recognize it. Programming is the step that teaches the car to accept a particular chip. Our programming page covers what that involves.
Cloning versus programming
Some chips can be cloned: the new key copies the identity of the old one, so the car sees the same key twice. Others must be programmed, which adds a new key to the car's list. Cloning needs a working original; programming works even when every key is lost. Which is possible depends on the car, and it is part of the first question a locksmith asks.
When a fob dies
Most "dead fob" calls are a flat battery, a coin cell that costs very little and takes two minutes to change. Before that, the car usually warns you on the dashboard. If the fob is flat and you need to drive now:
- Slide out the emergency blade hidden in the fob and open the driver's door with it. On many cars the keyhole is hidden under a small cap on the handle.
- Hold the fob against the start button, or put it in the marked spot in the console or cup holder. Most cars can read a flat fob at close range.
If a new battery does not bring it back, the fob itself may have failed or lost its programming, and it needs reprogramming or replacing. See our key fob page.
Buying fobs online
A fob has to match the car's frequency and chip type. Cheap fobs sometimes work; used ones taken from another car are often permanently locked to that car. Check the FCC ID on the back of your original and send it to a locksmith before you buy.
Questions people ask
How do I know if my key has a chip?
If the head is thick plastic rather than a thin metal bow, it almost certainly has one. The surest way is the year, make and model, which tell a locksmith exactly which key the car uses.
Can a chip key be copied?
Yes. The blade is cut and the chip is either cloned from your key or programmed to the car. Either way the copy starts the engine.
My fob's buttons stopped working but the car still starts. Why?
The remote transmitter and the start chip are separate. Usually the battery is going, and if a new one does not fix it, the remote needs reprogramming.
Is a laser-cut key harder to replace?
It needs a code machine that cuts that pattern, which is why some shops cannot do it. We cut both kinds on a Dolphin XP-005L on site.