What Is A Key Fob And Why Is It Important?

If you have a modern car, you most likely have a key fob. A key fob is an electronic device that allows you to lock and unlock your car's doors without using a physical key.

What Does A Key Fob Look Like?

Mazda OEM Key fob

Most key fobs are a few inches long and a few inches wide. A standard Mazda key fob has 2-4 buttons:

  • Unlock button
  • Lock button
  • Trunk release button
  • Panic button

In some cases, the keys are separate from the key fob. That's more common with older cars, though.

Some key fobs include a physical key to use to start up your vehicle. Other key fobs are completely keyless. You just have to use the key fob to enter the vehicle and then push a button on the dash to start the engine.

How Does A Key Fob Work?

Mazda key fob

Image Credit: HelpfulDIY

Some assemblies on a vehicle like the axle assembly are straightforward. They're easy to understand. Key fobs don't fall into that category. The system is pretty sophisticated and hard to understand. It's something a person 50 years ago would consider to be "black magic".

So how the heck can a small device like a key fob control a vehicle's locks and other functions from afar? It's because the key fob uses radio waves to communicate with a reader in the vehicle.

The key fob system has two main components:

  1. A short range radio transmitter
  2. A receiver unit

The short range radio transmitter is in the key fob. The receiver unit is in the car. A person can be up to 65 feet away from a vehicle when they press a button on the key fob. It works best if you're within 10 feet of your vehicle when using it.

The car creates a code that it sends out into the airwaves along with a signal to indicate which specific car the signal is going to. The key fob receives that code and then uses it to encrypt a message back to the car's receiver unit. If everything checks out, the receiver unit in the car unlocks the car's doors or performs another function as indicated by the fob.

The signal between the key fob and the receiver unit is called an RF field. You can't see it or hear it, but your vehicle can detect it by using a built-in antennae.

If you think this is all a little crazy, it's because it is. It works well and most people never have problems with it.

How Are Key Fobs Secure?

The way key fobs are programmed makes them very secure. If the signal from a key fob is intercepted by someone who isn't supposed to have access, there's no way for them to use it. They wouldn't know which code was sent from the car because each code only works with a specific key fob.

Summing Up

Modern Mazda vehicles come with sophisticated key fobs that allow people to lock and unlock their vehicles from afar. You'll need to have a way to start your car as well, but the key fob itself requires no physical input to make changes to your vehicle. They're also very secure for how they work and can't be duplicated by anyone except you using your specific code.

Key fobs are a standard feature in most modern vehicles and there isn't much that could go wrong with them between normal use. Key fobs are powered by batteries, which last only a few years. Key fobs should last the lifetime of the vehicle, but that doesn't always happen. Some drivers may break their key fob, or even lose it.

If you need to replace your key fob, you can usually do so through your local Mazda service center or dealership. They'll be able to program it for you. You could buy a replacement key fob from them, but you'd be overpaying. You'll save a lot of money by ordering a genuine OEM key fob from us. We're an authorized online dealer of OEM Mazda parts.

Look up your Mazda model here to get the right part number for your vehicle.