How to Reprogram a Car Key

Program a car key

Long gone are the days when the only key you needed for your car was the traditional one in the style used to open most locks. These days, almost every car will come standard with a programmable, electronic car key, known as a key fob. This is the remote that you get with your car and can use to lock or unlock your doors or even open the trunk without using the key itself. Although it is simply a feature for convenience, most people have become used to these key fobs and will find it truly annoying to be without them. As such, it is a good idea to know how to reprogram your car key, whether for additional security or if something happens and it accidentally becomes unprogrammed.

How Key Fobs Work

Key fobs rely on radio wave signals to communicate with your car lock. The key fob and the car contain memory chips, and when you press the appropriate buttons on your key fob, this action transmits a code to your car and tells it which action to perform (opening the trunk, locking the doors, unlocking the doors, etc.). Every time you use the key fob, the code will be randomly generated, but you need to always have this car key programmed, or the car will not be able to recognize the code sent from it.

Un programming

Whenever you purchase a new car, your key should already be programmed, and you may be fine using this key without reprogramming it for the lifespan of your vehicle. Occasionally there will be an error with the key fob and it will somehow become unprogrammed. Certain key fobs also have certain designs that mean it will become unprogrammed if you do something, such as press the button too many times while your vehicle is out of range. In other cases, your key fob may be lost or destroyed, in which case you will need to purchase a new one and program it, or hire someone to do the job for you.


The specific steps to reprogramming a key fob will vary slightly between vehicles, but generally speaking, it is the same in all cases. Usually, you should program all of the key fobs at the same time, as not doing so may prevent those you don’t reprogram from working in the future. To program most car keys, put your key in the ignition, turning it to “on” without starting your engine. (Certain cars may require you to repeat this step). When your car enters the program mode, you will press whichever button on your car key must be programmed to sync it. You can then turn off your car and use the key fob in the future.

Hire a Locksmith

Many people find it straightforward to reprogram a car key themselves, but others are simply not confident enough to do so. In this case, you can easily hire a locksmith to do the job for you. Locksmiths generally charge significantly less than a dealership would and will be able to easily get the job done in minutes. As a bonus, they will be able to come to you instead of you having to take the car in to your dealership for the programming.

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