What is a Transponder Key?

One thing I’m often asked is, what is a transponder? Do I have one? The idea behind the “chip” keys is that no amount of brute force will allow thieves to get away with your car. Most cars made after 2004 have transponder chips, so if you have a late model car you probably have one. The easiest way to tell is if the key that starts your car has a plain metal head, then it does not have a transponder chip. To really understand what you have and what to expect, I’m going to cover a few basics here. There are basically two types of chipped keys. In 1986, GM introduced the first type which is the VATS system, or vehicle anti theft system. This system was in place on their vehicles until around 2000. With these keys, you’ll see a black rubber pellet in the key and it will have a small piece of metal in the center. The way this works is the ignition has two wires that go to the computer when you insert a VATS key, these wires measure the resistance in the chip if it reads correctly the car starts, if not it shuts down for four minutes. These keys are more cost effective than the modern chip keys but they have their own flaws,such as the ignition wires move when you turn the key and are prone to breaking resulting in a no start condition.

Now let’s move onto the more modern transponder key system. In my opinion, this is a well designed well thought out system. This system is similar to an RFID card like you’d use on a gate or at your place of work. Basically you have a small chip embedded into your key and an antenna at the face of your ignition. When the car is turned on, the antenna generates a magnetic signal the key receives this signal and sends a signal back the ECM, or computer, reads this and allows the car to start. This system is more fool proof, as the chip is in the rubber part of the key so it’s safe from harm and there is no wiring in motion when you start the vehicle, so it’s less fault prone. These keys are a little more costly and based on the vehicle type you have, they can be pretty easy to get made aftermarket or somewhat difficult.

How do I know my car has one if I already lost my keys? Trust is important in this industry, you have to know what you’re buying. So Have a service key made! A service key is a plain metal key that does everything a chip key does but will not allow the car to start, as it has no chip. Whenever most locksmiths make a transponder key, they make a service key to test the cuts prior to starting the programming this saves the cost of a transponder keyblank, if there is a cut that’s off. Because of this process, a service key should never cost much, if anything. I provide one every time. This will demonstrate whether or not your car has a chip; just try it in the ignition and if it doesn’t start, you have a transponder. You can keep the service key as a spare for when you are locked out or lose keys.