Updated at: 02-08-2023 - By: Lucas

A remote keyless entry system is a type of electronic locking system used in modern cars to control who can get in and out. As the name suggests, the system lets you lock or unlock car doors with a handheld device. Keyless entry systems can use remote fobs or more modern Smart Keys.

What is remote keyless entry system and do I need Key Fob Programming?

Key fobs, which are also called keyless entry remotes, let you control your car’s locks, trunk, panic alarm, and even remote starter from hundreds of feet away.

The security of vehicles has come a long way over time. In the past, mechanical locks and key combinations were used to open the doors of cars. Modern cars have sophisticated locking systems that are safer than the ones that came with older cars. Even though the auto industry is moving toward keyless entry systems, many people still use mechanical door locks.

Traditional car locks can be picked, just like other mechanical locks. On the other hand, keyless entry locks are harder to break because they are electronic and have hard-to-crack codes.

A more advanced type of keyless entry key lets the car owner open the doors and start the engine without physically pressing a button or inserting a mechanical key. These so-called “smart keys” use sensors to open doors and turn on the car’s engine. But mechanical keys are still used as a backup for smart keys.

How does the key fob security system work

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The keyfob system affects both the ignition and the door lock of a vehicle. Transmitters, transceivers, or transponders are used in the system. These things talk to each other by sending and receiving radio waves. When the receiver sends a signal to the car’s onboard computer, the computer sends a signal to the actuators on the doors to open or close them.

The frequency at which all key fobs work is between 300 and 400 MHz. Keyfob signals must be unique so that other car owners can’t get into your car. This unique signal is made by the keyless entry system with “rolling” or “hopping” codes. Every time the key fob is used, the codes change. That’s why it’s called rolling or hopping.

Rolling codes keep thieves from using code-grabbing devices because the codes change every time the key fob is used. They also keep other key fobs from working. The codes on key fobs are also encrypted, making it very hard for thieves to figure out what they mean.

Some key fobs have safety features that stop the engine from running. By stopping fuel from getting to the engine, the system is meant to stop the engine from being hot-wired. The engine immobiliser works the same way as the keyless entry system. It uses radio signals and codes that change every time they are used.

Immobilizers give you more security, especially if someone copies the mechanical key that came with the fob. Even if the duplicate key is an exact copy, the car won’t be able to find it. For the key fob to work, it must have the code that the car’s ignition system looks for.

The smart-key system is more advanced, but it works the same way as keyless entry remotes. Radio signals and changing codes are also used by smart keys. But smart keys are different because they have sensors that can tell when the smart key (and the person holding it) is close to the car. When the key is near, the smart-key system automatically opens the doors, turns off the immobiliser, and starts the engine.

What you need to reprogram when key fob programming comes in question (software, tools, etc.)

It’s not as easy to replace a fob as it is to replace a TV remote. For the onboard computer to recognise the new keyfob, it needs to be reprogrammed. You may also have to programme any spare fobs you buy.

You can re-program your key fob by hand or with a programming device. Most new cars have built-in ways to programme the key fob. Model to model, the steps for programming may be different, but the important ones are always the same. Basically, the car has to be put into programming mode by hand so that it can recognise the fob that needs to be programmed.

Key Fobs can also be reprogrammed with the help of special hardware or software. (Give some examples of hardware and software)

How do you reprogram remote key fobs?

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Make sure your remote key’s battery is charged enough to run the device before you try to programme it. Follow these steps to programme remote key fobs that don’t have immobilisers:

First, get in your car and lock the doors.

Step 2: Make sure the door locks are on so you don’t mess up the process of reprogramming.

Step 3: Put your car key in the ignition switch and turn the switch to the “ON” position.

Step 4: Press the “Lock” button on the keyfob while the key is in the “ON” position.

Step 5: Put the key back in the “OFF” position.

Step 6: Repeat steps 3, 4, and 5 quickly at least four times until you can hear the lock cycle.

Step 7: Check to see if the new key fob works.

Step 8: If everything checks out, you’re done! You’ve done a good job programming your key fob.

How can smart key fobs with immobilisers be reprogrammed?

Smart fobs with immobilisers are harder to re-program than keyless entry fobs without immobilisers. This is because the system that stops the car from moving has its own security code. This is also true when programming fobs with mechanical keys that can be used more than once.

Before you programme your duplicate key fob, make sure that the blank blade of the key is cut to the same shape as the original key. Follow the steps below to set up smart keys:

Step 1: Put the duplicate key that hasn’t been programmed into the ignition switch.

Step 2: Plug your programming device into your car’s OBD2 port.

Step 3: Use the programming device to run the software that works with your car. (See the example up top)

Step 4: Follow your programming device’s instructions carefully.

Step 5: Wait for the device to programme a new code into your key fob.

Step 6: Turn on your car’s ignition to see if it recognises the key.

Step 7: If everything went well, you’re done programming your key.


Does AutoZone program key fobs?

No, not really. AutoZone doesn’t offer services for reprogramming, per se. But the auto store sells replacement key fobs, and you could ask a salesperson there to help you re-program the new fob.

How much does it cost to program a key fob?

Most of the time, reprogramming a key fob costs between $50 and $100. For more advanced fobs, it can even go up to $500. If you need a new key to go with your newly programmed keyfob, you can expect to pay up to $200 at the dealership. Most of the time, certified locksmiths charge about $25 less than dealerships.

Do aftermarket key fobs work?

Yes. Almost any car can use an aftermarket key fob, as long as it is compatible with the car. Before buying a replacement or spare fob, you should always check the model number on your old fob to make sure it will work with the new one.

Can any key fob work in any car?

No. Every time a key fob is used, its signal changes. This keeps other key fobs from working and keeps thieves away. The signals are also encrypted to make them even safer.