Can You Program a Key Fob Yourself? – An Easy Guide

can you program a key fob yourself

Indeed, key fobs are convinient in controlling vehicle functions such as starting the engine, the alarm, trunk and car door. To facilitate these hands-free vehicle operations, signal transmission between the electronic key (FOB) and the vehicle is necessary. Nonetheless, fobs often malfunction due to a fault in the signal delivery. One will probably wonder, can you program a key fob yourself in such situations?

In this write-up, we have put together a step-by-step guide on reprograming a key fob yourself. Accordingly, possible key fob malfunctions shouldn't prevent you from buying a used or an auction car. Remember, technology like electronic car keys will always make work easier but at the price of taking time to understand the working mechanism. So, without the need for a new key fob, let's first understand the security mechanism of a key fob for easier reprogramming.

Understanding the FOB System

Primarily, key fobs enhance security on two fronts relating to starting the car and controlling entry into a vehicle. Previously, the RF system was used for enhancing car entry security, but it proved less effective due to easy code and signal manipulation. Also, there was the infrared system which required pointing a security remote toward the target car. Fortunately, the modern fob locks are more sophisticated, with synchronized code generation between the fob and the vehicle's receiver.

As such, the key fob system is more secure thanks to its transponder and ECU technology. With this new technology, you will have the added advantage of starting your car with the fob remote and ignition key. Moreover, some luxurious and advanced vehicles use these security codes to adjust to the owner's specifications. Overall, a healthy car battery voltage is necessary for such fob functions.

In particular, the transponder technology applies code transmissions between the electronic key and the vehicle's frequency receiver. Depending on the fob button you press, the radio frequencies will deliver unique codes for enabling the target function. However, despite the complex working mechanism of a key fob, most models can easily be reprogrammed.

How To Reprogram a Key Fob

Before highlighting the necessary fob reprogramming steps, it's important we highlight that different vehicle models use different key fobs. In this context, we have prepared the simplest approach to most general key fobs in the market. Nonetheless, some will require special reconfiguration, which is more complex and will most likely require the input of a specialist. That aside, follow these reprogramming steps if you want to give it a shot.

Step 1: Replace the Key Fob Batteries

First, your key fob is probably not working properly due to drained batteries. Also, replacing the key fob batteries before reprogramming will make the process more efficient with faster frequency transmissions. Luckily, key fob batteries are easy to replace and even more, they are cheap and locally available. Also, if you can consider a car battery replacement to avoid instances of power loss.

Step 2: Enter Your Target Car

Holding the key fob to be reprogrammed in your hand, get in your driver's seat, not forgetting your car keys if you have them. Then, close all the doors. Leaving even one door open might disrupt the configuration process.

Step 3: Turn on The Ignition

If you are using the key system, turn it to the ON position. This process is necessary to power your vehicle's electrical system, including the entire system relating to your key fob. As you turn on your ignition, ensure it's not on radio mode to avoid any interruptions of your fob interruptions. Remember, you should just turn the ignition ON and not start the engine.

Image Credit:

Step 4: Press the Remote Lock Button Key

While at the ON position, press your fob's lock button and then turn the ignition key back to OFF. Repeat this around three times with the cycle ending with the OFF position but making sure you resume ON. This process sends an electronic indicator to your vehicle's control box that the owner's key is in the ignition. Subsequently, the control unit will save your fob and key information as part of the reconfiguration.

Step 5: Listen for a Locking Sound

Repeating the ON and OFF cycle as you press the fob's lock button will result in a lock sound. This sound is a sign you have begun the reprogramming mode. In most cases, you'll have to repeat step 4 if you don't hear the lock sound the first time or subsequent other few times. Once you've entered programming mode, press your fob's lock button again within 5 seconds, and your programming will be complete.

Step 6: (OPTIONAL) Programming More Remotes

Fortunately, you can repeat the programming process for up to three remotes. Therefore, if you have additional remotes, ensure you press the target fob's lock button within 10 seconds after hearing the lock sound (the sign of entering programming mode). Remember, for the primary remote, you press the lock button after 5 seconds, and for an additional remote, it's 10 seconds.

While at it, we recommend being careful with the initial programming steps while adding other key fobs. In most cases, it is highly likely to wipe data about other fobs while reprogramming multiple remotes. As such, you should turn to the OFF positions and then press the lock button of the next fob you're programming and turn the ignition off again. Therefore, quickly reprogram the subsequent fobs to avoid delays between the processes that may render the cycles useless.

Step 7: Turn off the Ignition

Once all your fobs have been reconfigured, don't forget to terminate the programming process. To do this, simply turn your car's ignition OFF. Remember, the secret behind successful reprogramming is being swift with the procedures, including this step. Also, press the fob's lock button a few seconds after turning your vehicle off and removing the ignition key immediately.

Step 8: Test Your Fob (s) Outside Your Vehicle

Finally, it's important to test and see if this process was successful. Step out of your car and remember to close all the doors, then proceed to test your reprogrammed fob using the lock and unlocking functions. If your fob is non-responsive despite having new batteries and repeating the process, you can consider the services of a specialist.

Not to worry, some car manufacturers don't intend for their key fobs to be easily reconfigured for enhanced security. In such cases, they recommend consulting specialists who apply specific programs and hardware for reprogramming. Notably, key fob programming by a specialist can be expensive, but your local auto locksmith company will probably be cheaper than your authorized car dealer.


Reprograming your key fob is paramount to keeping your car secure for only authorized ignition and entry. Fortunately, car owners can reprogram key fobs themselves. The probability of this procedure working is high but except for some more luxurious and complex vehicle models. Even for such models, the end goal is upholding maximum vehicle security.

In as much as the fob security system is more convenient and effective, some car owners still prefer the traditional key lock and ignition setup. That's still okay, but a key fob's other advantages include reduced risk of losing keys and increased vehicle monitoring for the alarm feature. That said, always remember to maintain your key fob (s) in the right working conditions for maximum functionality.

Frequently Asked Questions on Reprogramming a Key Fob

1. Do aftermarket key fobs work?

Indeed, aftermarket key fobs work as long as you match them to the right car model. Fortunately, the fob technology isn't restricted to certain models, meaning it's possible to find an aftermarket fob, especially for the most used models. However, if you own a luxurious model, you will most likely not find an aftermarket fob.

Also, it's possible to find unbranded aftermarket fobs. Nonetheless, such models will have less working probability, meaning you should avoid them despite their affordability. Moreover, we don't recommend aftermarket key fobs since you are unsure about their functionality. Therefore, you should go back to your authorized car dealer for a legit key fob.

2. Why is my car not detecting my key fob?

There are a few reasons your key fob could be non-responsive. First, it can be because of a bad key fob battery. Secondly, it could be because of erased memory, as is the case of reprogramming your key fob. Thirdly, your key fob might be working fine, but your vehicle's receiver has faulty, probably due to inadequate power caused by low car battery juice.

3. Can I get a new key made from the VIN?

Yes, you can as long as you can prove that you are the legitimate owner of the vehicle in context. Once verified, your car dealer or manufacturer can make a new key or fob with your vehicle's VIN (Vehicle Identification Number). Subsequently, a unique code will be pulled from your specific vehicle and used to make another unique key.

Image Credit: