Transponder Keys: A Vehicle Owner Guide

Many modern vehicles are started with a special type of key known as a transponder key. Some vehicle owners, however, may not be totally familiar with this fairly recent piece of technology. The following article is a basic guide to transponder keys and some of the issues surrounding their use.  

How It Works  

A transponder key works differently from a standard key because it has a transponder chip in the plastic part of the key just above the blade. The chip sends out a signal that a receiver inside your ignition must recognize. If the receiver does not recognize this signal the car will not start, regardless of whether the key fits in the ignition.  

The Purpose  

Transponder keys came onto the market in response to auto thefts. In particular, the keys make it extremely difficult for a thief to "hot wire" a car. Hot wiring is a method of starting vehicles without a key by connecting certain ignition wires. Even when theses wires are connected or wired together, however, a vehicle that uses a transponder key will not start because the receiver in the car does not get the signal it requires to turn over the engine. 


Although transponder keys decrease the likelihood that a vehicle will be stolen, one negative aspect is that they are considerably more expensive than standard keys. Transponder keys can easily cost hundreds of dollars, a significant expense compared to low-cost standard keys.  

For this reason, losing a transponder key can be costly, especially if you obtain your replacement key from a dealer. One good idea to save some of the expense of buying a replacement transponder key is to check with a local locksmith. They may be able to provide you with a new key for much less than a dealership. 

Keep in mind that if you are just looking for an extra key to unlock the doors and trunk, you do not need a transponder key. A standard key is fine as long as you do not need it to start the engine.


If you have an older model car with no transponder system or a car that does not use a transponder key for any reason, you may want to consider having the vehicle retrofitted with a transponder key system. This change will make your vehicle less likely to be stolen by auto thieves. The retrofit is not inexpensive, but may increase your peace of mind.  

To learn more about a transponder key or to get a replacement, contact a qualified locksmith.