Why did my key fob stop working?

If you're the proud owner of a car with keyless entry, then you're familiar with the convenience of a key fob. These little devices allow you to unlock and lock your car with just the push of a button. But what happens when your key fob stops working? Don't panic just yet - in this article, we'll explore some common reasons why your key fob may have stopped working and what you can do to fix it.

What is a Key Fob?
A key fob, also known as a remote key or smart key, is a small electronic device that communicates with your car's keyless entry system using radio waves. The fob contains a microchip that is programmed to communicate with your car's security system when you push a button. The communication between the key fob and the car is what allows you to unlock or lock your car doors, open the trunk, and even start your car's engine without inserting a key into the ignition.

Dead Batteries

Battery Life Expectancy
One of the most common reasons why your key fob may stop working is that the battery has died. The life expectancy of a key fob battery varies from one manufacturer to the next, but most batteries last between three and five years. Some manufacturers recommend that you replace your key fob battery every two years, regardless of whether it's still working or not.

Signs of a Dead Battery
If the battery in your key fob is dead, you may notice that the range at which you can unlock your car is reduced, or that pressing the button multiple times is required to unlock your car. In some cases, your car's alarm may also sound when you try to unlock your car using the key fob.

Replacing Batteries in a Key Fob
Replacing the battery in your key fob is a simple task that you can do yourself. Most key fobs have a small indentation that you can insert a coin or a flathead screwdriver into to pry open the device. Once you've opened the key fob, you can remove the old battery and replace it with a new one. Make sure you purchase the correct type of battery for your key fob.
 

Signal Interference

What Causes Signal Interference?
Another reason why your key fob may stop working is signal interference. Signal interference can happen when radio waves from other electronic devices or security systems disrupt the communication between your key fob and your car's security system. This interference can prevent your key fob from sending or receiving signals to and from your car.

How to Test for Signal Interference
One way to test for signal interference is to try unlocking your car with your spare key fob. If your spare key fob works, but your primary key fob doesn't, then signal interference could be the issue. You can also try standing closer to your car when using your key fob, or try moving to a different area to eliminate potential interference.

Preventing Signal Interference
To prevent signal interference, keep your key fob away from other electronic devices that emit radio waves, such as your cell phone, tablet, or laptop. You should also avoid parking your car near buildings or other objects that could block the signal from your key fob.

Damaged Key Fob

Types of Damage to Key Fobs
A key fob can also stop working if it's been damaged. This damage could be physical, such as if the key fob has been dropped or exposed to water, or it could be electronic, such as if the microchip has been damaged.

Signs of Damage to a Key Fob
Signs of damage to a key fob can include a cracked or broken case, buttons that are unresponsive or stick when pressed, or a key fob that doesn't work at all.

Repairing a Damaged Key Fob
If your key fob is damaged, you may be able to repair it yourself if the damage is minor. For example, you could replace the case or buttons if they're damaged. If the microchip has been damaged, however, you'll need to replace the entire key fob, which may require a trip to your dealership.
 

Programmed Key Fob

What is a Programmed Key Fob?
A programmed key fob is a small remote device that allows you to lock, unlock, and perform other functions with your vehicle. It contains a chip that communicates with your vehicle's security system to identify and authenticate the key fob. Without a programmed key fob, your vehicle's system will not recognize the key and will not allow you to start the engine or perform any other functions.


How to Test a Programmed Key Fob
To test your programmed key fob, stand close to your vehicle and press the lock or unlock button. If your vehicle responds to the button press and locks or unlocks, then your key fob is working correctly. If your vehicle does not respond, then there may be an issue with your key fob or your vehicle's security system.

Reprogramming a Key Fob
If your key fob has stopped working, you may be able to reprogram it. To do so, consult your vehicle's owner's manual for instructions specific to your make and model. In some cases, you may need to bring your vehicle and key fob to a dealership or auto repair shop for reprogramming.
 

Repairs and Replacements

When to Repair or Replace a Key Fob
If your key fob is not working correctly, it may need to be repaired or replaced. Signs that your key fob may need attention include buttons that do not respond, or a key fob that does not work at all. If your key fob is lost or stolen, it should be replaced immediately to prevent unauthorized access to your vehicle.

The Cost of Repairs and Replacements
The cost of repairing or replacing a key fob can vary widely depending on the make and model of your vehicle and the type of key fob you have. In general, repairing a key fob may cost less than replacing one, but it is essential to consult a professional to determine the best course of action.

DIY vs Professional Repairs and Replacements
While it may be tempting to attempt to repair or replace your key fob yourself, this can be dangerous and may result in further damage to your vehicle. It is always best to consult a professional to ensure that the repair or replacement is done correctly and safely.
 

Preventative Maintenance Tips

Cleaning and Maintaining a Key Fob
To extend the life of your key fob, it is essential to clean and maintain it regularly. Use a soft cloth to gently clean the surface of the key fob and keep it free from dirt, grime, and other debris.

How to Extend the Life of a Key Fob
To extend the life of your key fob, always be gentle with it and avoid dropping or exposing it to extreme temperatures. Keeping your key fob away from magnets and other strong electromagnetic fields can also help prevent damage.



Key fobs are an essential part of modern vehicles, allowing you to easily lock, unlock, and perform other functions. If your key fob stops working, it may need to be repaired or replaced, and it is always best to consult a professional for this task. To extend the life of your key fob, clean and maintain it regularly and avoid exposing it to extreme temperatures or electromagnetic fields. Key fobs offer a great convenience for car owners, but they can also encounter issues that require repair or replacement. By following the tips outlined in this article, you can troubleshoot and fix many key fob problems, and also take steps to prevent issues from arising in the first place. Remember, taking care of your key fob can lead to a longer lifespan and a hassle-free experience when accessing your vehicle.

If you're having issues with your key fob, Hillside Auto Repair has got you covered. Whether you need a repair, replacement, or reprogramming, our expert technicians can handle it all. Don't stress about your car being inoperable because of a faulty key fob - just bring it into Hillside and they'll have you back on the road in no time.