Car Key Fob Programming: Can You Do This at Home?

Key fobs are electronic car keys that can control your car’s doors, alarm, and trunk. Some modern cars allow you to start your vehicle from a distance with the key fob. But, if your car key stops working, key fob reprogramming is needed to control your vehicle again.

Your key fob can stop working because it lost its data or is malfunctioning due to signal loss. Fortunately, you can reprogram your key fob at home with several tools. If you’re not handy with tools, hiring a professional locksmith is advisable.

This guide will cover how to reprogram key fobs without needing special tools. This way, you can program your car key fob without needing an auto-dealer or locksmith.

1 Key Fob Reprogramming
You might have to reprogram your key fob because of a signal loss or loss of data. Sometimes, you have a new car key and will have to connect it to your car. 

How to Reprogram Your Key Fob

Since there are different car models, makes, and years, you can expect that the methods of reprogramming key fobs will differ. The process of key fob reprogramming explained below is the simplest way.

1. Replace Your Key Fob Battery

Before you work on key fob reprogramming, you need to replace your key fob battery. A faulty or dead key fob battery can hinder the reprogramming process. Luckily, the key fob batteries are easy to replace and affordable.

You can check the owner’s manual to learn how to replace them. Follow the steps below to replace your key fob battery:

  • Open the fob from the notch. You can quickly identify the gap after reading the user’s manual.
  • Pop it open with a screwdriver. You should see a round battery.
  • Identify the type of battery from the markings. Based on the model, you can purchase a new one.
  • Use your finger to remove the old battery, and put the new one in the same spot.
  • Close the key fob tightly.

It’s advisable to replace your key fob battery every five years or before reprogramming.

This video will show you how to replace your key fob battery easily:

2. Enter the Car

2 Car Key Fob
Before reprogramming your car key fob, you should ensure you lock the car doors or this will disrupt the process. 

Open your car and sit in the driver’s seat. Ensure you’re holding the car key fob. When you enter the car, close the doors, as leaving them open can affect the process. If your car is not opening from the outside, there is a problem with your key or car door.

3. Turn the Ignition On

Insert the key in the ignition and turn it on. Keep the key in the ‘On’ position, so the electrical systems are on without starting the engine.

4. Click on the Lock Button on the Key Fob

3 Remote Key Fob
The lock button on a key fob differs based on the make and type of key. Identify the lock button on your remote key fob before the process so you can easily click on it.

Press the lock button as the remote key fob is in the ‘On’ position. Then, turn the key back to ‘Off.’ Repeat the same process three times, and end with the key remaining in the ‘On’ position.

This process sends a signal to the electronic control units, and the signal includes information about your key fob. The control unit saves the data afterward.

After doing this, listen for a lock sound. That is a sign that your key fob is being reprogrammed. Then, press the lock button again before five seconds, and your key fob will be reprogrammed.

If you have more remotes, click on the Lock button within ten seconds after entering the reprogramming mode. This allows you to successfully re-encodes all remotes.

5. Turn the Ignition Off

After completing the steps above, turn the ignition off. This will terminate the reprogramming process.

6. Test the Key Fob

Come out of your car with the key fob, and close all the doors. Then, test your key fob by trying to unlock and lock your vehicle. If it is working, you can go on to use your key.

Steps to Program a Push-Button Starter

4 Keyless Fob Reprogramming

Reprogramming your keyless fob is different from a car key fob. In many cases, it does not work and you will need a professional locksmith with special tools.

If your car uses a push-button starter instead of a keyhole, it will be trickier to reprogram your keyless ignition fob. The steps below are not foolproof, but you can try them out first. If it does not work, a dealer or locksmith can program it for you at a price.

  1. Hold your key fob and get into the driver’s seat. Ensure the doors are closed.
  2. One hand should be on the starter while the other is on the key fob. Keep in mind that you have to work quickly and timely.
  3. Press the starter button 15 times quickly, with about two seconds between each push. Make sure your foot is not on the brake while doing this.
  4. After that, click on the lock button on the key fob immediately.

If you programmed your keyless fob successfully, the car would lock. You can repeat the process if it does not work, as it is hard to get the timing right.

After programming the car remote key, you can come out of the car and test it.

Needing Specialist Hardware for Key Fob Reprogramming

Sometimes, key fob programming for your car might not work, and this is when you need specialist tools to get the job done. You can call your authorized car dealer to reprogram your key fob, but this is the most expensive option.

To spend less, you should contact an auto locksmith company or professional mechanic to reprogram your car key fob for a lower price. It’s advisable to get a separate master key made in case you misplace the key or need reprogramming in the future.

Understanding Car Security

5 Modern Car Key
Your car is secure based on the entry and starting. Modern cars come with security features in the car entry and car start process. 

Car security is set up in two sections of the car. These include the car entry and car start. Many modern cars don’t require you to insert your car key into a keyhole before you can open it since there is remote locking and unlocking. This makes them more secure than older cars.

Modern cars use a high-tech rolling code system that creates a new code each time, syncing with the vehicle’s receiver. This makes it hard for thieves to use another key fob to open your car, unlike before when cars could be unlocked from any similar key. Nowadays, you can even open your car with your phone.

Cars are also secure with the starting system, as key fobs are designed with a signal that matches the ignition system. In many vehicles, if you use the wrong key, you would be unable to start the car. Even with a keyless fob, the vehicle recognizes the signal when you’re with the key and will start after pushing the button.

Importance of Checking the Key Fob Battery

In many cases, your key fob isn’t working because of a dead or faulty battery rather than a problem with the programming. Before buying a new key fob, you should check if you need to replace the battery.

Many car key fobs use a small battery that looks similar to your watch battery. You can easily purchase it at home improvement stores and pharmacies for a couple of dollars. It’s recommended to replace the battery before reprogramming the fob.

Your car might not be starting because of a bad starter relay, and not a faulty key fob. Covering all your bases is important to avoid wasting time and money.

What is a Transponder?

A transponder is a device that receives a radio signal and automatically transmits a different signal. Transponder technology is widespread in many modern cars, as key fobs feature a transponder chip. The chip is connected with a receiver in the ignition.

The chip is triggered when you start the car and sends a signal to the engine control unit. If correct, the immobilizer is disabled, and you can start the engine. If not, the car will not start.

Learn about transponder car keys below:

How Long Does It Take to Reprogram a Key Fob?

If you are reprogramming your key fob, it will take a couple of minutes as long as it’s successful. Locksmiths and dealers usually take up to 30 minutes to program or reprogram your key fob. If you misplaced your key and the locksmith is cutting a new one, the process will take up to an hour.

How Much Does It Cost to Reprogram a Key Fob?

It costs between tens and hundreds of dollars to reprogram your key fob. This depends on the type of key fob, the average cost of locksmith services in your area, and the make and model of your car. If you’re using a professional, you should consider hiring a locksmith rather than a dealership.

A locksmith provides services at lower prices and will also drive to you if you are stuck with a faulty key fob. If you do this yourself, it costs almost nothing besides buying new key fob batteries.


Can I reprogram a new key fob myself?

Most of the time, you can reprogram a key fob yourself. This is rarer with a car using a starter button, and many cars require specialist tools to reprogram the fob.

How can I erase key fob memory?

If you want to replace your car key fob memory, you need an OBD2 diagnostic tool that can do this. There will be a specific tool for your car model.

Can I buy a key fob myself?

Yes, you can. Key fobs are easy to access in different stores, including places that sell car accessories, home improvement stores, and even pharmacies.


Key fob reprogramming can be very easy, or it might not work, depending on your vehicle type. Many car owners have succeeded in doing it at home, and you can try it too and save money on the project. If it does not work, look for a reliable and affordable locksmith that can get you to the road as soon as possible.

Key Fob Programming 2 Key Fob Programming