How Do Transponder Keys Work?

To the casual observer, transponder car keys can seem nothing short of magic. A transponder key system is something of a misnomer, though, since there’s no physical key involved. Instead, the transponder sends a signal to the vehicle’s onboard computer, which is interpreted as lock/unlock for the car’s security system. Chances are, if you’re a Fairfax, VA resident who’s purchased a car in the past few years, you have a transponder key.

Why are transponder keys popular?

Like most access control-style locking systems, transponder key systems are popular because they’re much more secure than a traditional lock and key system. Since everything is done via low-frequency radio waves, there’s no key to duplicate or lock to pick, making it tremendously difficult for car thieves and burglars to gain access to your vehicle.

Most modern automakers have moved over to transponder keys not only because of the security, but also because of their simplicity and flexibility. It’s easier to program (and reprogram) transponder keys off the assembly line than it is to cut keys—especially microchipped keys.

How do they work?

As mentioned above, a transponder key system works by sending a signal from your key fob to the car’s onboard computer. The signal is interpreted as lock/unlock depending on the button you push and the frequency sent by the fob. Many transponder systems are also tied to the ignition system, meaning the transponder also works to start the car (think push-button ignition). The presence of radio waves signals to the vehicle that the keyholder is present.

Ever wonder why you need to be right next to a car to use the transponder key? It’s because the radio frequencies emitted by the fob are so low-level, they dissipate beyond a certain distance. Most keys need to be within five to six feet of the vehicle to work. This is by design, and it adds even more safety to the transponder key system.

How do you replace a transponder key?

Though they’re more difficult to create, getting a transponder key replacement isn’t impossible. A locksmith with the proper programming tools can create a new key that works with a vehicle’s existing transponder key system.

The trick is understanding that different manufacturers use different programming systems. For example, Ford uses its Passive Anti-Theft System (PATS) to program transponder keys, while General Motors uses Circle Plus keys and PASSKey3 (PK3) keys. These programming differences are subtle, but they affect how the transponder key communicates with the vehicle. For this reason, it’s important to work with an auto locksmith in Fairfax, VA that has the ability to program transponder key replacements for all makes and models.

Convenience and security, all in one

There are more than a few reasons why transponder key systems have become commonplace for late-model vehicles. The only inconvenient thing about them is trying to get into your vehicle without the right fob! Thankfully, there are locksmiths like Artie’s Lock and Key that can make getting a new transponder key simple, so you can get back behind the wheel.

Categorised in: Auto Locksmith

This post was written by Writer