Transponder Key – We came across this great video that explains how to tell if your car has a transponder key or not.
Mitch Schaffer is the owner of a locksmith company in the northern USA. He does a really great job of explaining how transponder keys work and how to tell if you have one.
Thanks to Mitch for this great video!
If you are in the Dallas / Fort Worth metroplex, call Michael’s Keys if you have any questions or if you need new transponder keys. Our prices are much less than you would pay at the dealer. Michael’s Keys Dallas -> (972) 498-1021

Transponder keys Explained
The Transponder Key Is A Security Device
The transponder key is a security key that most modern cars use for starting the vehicle. This type of key has a small rf transmitter built into the top or plastic portion of the key.
Used on Most Modern Vehicles
These keys have been around since the 1990s. There are a few exceptions, but for the most part, cars built in the last couple of years utilize a transponder key ignition system.
Receiver And Transmitter – It’s A System
During the starting sequence, the transmitter sends a signal to a receiver connected to your ignition switch. It is like an electronic switch in front of the ignition switch – a pre-switch if you will.
A Problem For Remote Car Starters
This video is essentially about “remote car starters”. It shows how the transponder affects the installation of such a system.
Now think about that for a few seconds. How can a remote car starter work if you have the transponder key in your pocket? Remember, the rf transmitter signal is very weak. It has to be right next to or in the ignition keyhole.
If you get a remote starter you have, to make the system work, you’ll ned to have a remote bypass module installed. That is, if your car requires a transponder key.
You May Need A Remote Bypass Module
The remote bypass module only overrides the transponder key for a few milliseconds, and only when you are starting the car. The rest of the time full security is intact.
How You Can Find Out If Your Key Is A Transponder Key
So, how do you know if your car uses a transponder key.
Well, you can ask the dealer. You can look it up online. Both of these can be quite time consuming.
DIY Transponder Key Test
An alternate way would be to disable the transmitter portion of the key and see if the car starts. If it starts, most likely you don’t have a transponder key. If it doesn’t start, then you are sure that you have one.
OK, so how do we disable the transmitter. Well, actually we aren’t going to disable it we are just going to shield the transmitter so that the receiver can’t see what is being transmitted to it.
Here’s how you do it.
Take some aluminum foil. About a 1 square foot section. Fold it several time so that you maintain the square shape. Then make a small hole in the middle of the square. Push the key through while wrapping the foil around the plastic upper portion of the key – the part you grab hold of to turn the key in the ignition.
This should have that transmitter shielded!
Insert the key into the ignition and try to turn the car on. If you can’t get the car to start you know that you have a transponder key. Remove the foil and try to turn it on again. The car should start.
Not A Foolproof Method
It is possible that if your car starts while shielded, you may not have shielded it well enough to stop all the rf from the receiver. So this method is not 100% foolproof.
But, as stated before, if the car won’t start you can be sure that you are using a transponder key.
Check out the video for a step by step visual on how to do this test.
For additional information, here is a Wikipedia article on Transponder Car Keys.
Call Michael’s Keys For Transponder Keys In Dallas, Texas
Michael’s Keys Dallas – (972) 498-1021