How to Fix a Key Fob That isn't Working
If your key fob does not work then you can fix it by following just a few steps. First, make sure that it's not your backup remote.
If the backup is able to lock and unlock your car doors it is most likely an issue with the primary remote. The majority of car remote key malfunctions result from circuitry or battery problems.
Battery
It is not uncommon for the battery in a key fob for cars to degrade. It is quite simple to replace batteries, but it is crucial to ensure that you select the correct one that you can refer to your owner's manual, or contact the dealer of the manufacturer to find out the kind of battery you require. It is also crucial to examine the battery compartment, since batteries that are not working properly can release caustic chemicals that can harm the remote. If changing the batteries does not solve the problem it could be that there are other issues that require attention from a professional. If buttons are damaged or stuck for instance, it may be necessary take the remote apart and rework each component. You could also try reprogramming the vehicle to recognize the new fob.
Buttons
Key fobs may become dirty and worn out from frequent use. It is not uncommon for buttons to cease functioning, or require a hard press to get them working. car keys repair can be a huge hassle especially if you're out of town and need to start your car. Fortunately, even worn out or broken buttons can usually be fixed with a bit of time and a few materials you might already have in the house.
First, check that the batteries are correctly placed and that the indentation on the back of the button has been filled. Open the remote carefully and examine the circuit board. Look for signs of corrosion or other signs that buttons are worn out or damaged, such as missing paint that is conductive. Utilizing a Q-tip dipped in alcohol to gently clean any membrane contacts that are worn or have conductive paint missing. Do not rub too vigorously in order to damage the conductive paint and stop the button from firing when it is pressed.
Also, be sure to check the battery connector's terminals to ensure an unattached solder connection. Soldering them back to their original position will restore the button's functionality if this is the case. You can apply the same method to restore functionality to any other loose connection within the fob.
In the end, if any of the buttons made of rubber that are on the front of the key fob have stopped working or require a very hard press to work it is likely the graphite disks that are on the back of the button are wearing down and require replacement. You can do this by rubbing a pen over the disks. This should bring the button back to life.
If none of this is useful or if the button still does not respond to a hard press, then it may be the case that the circuit board itself has gone bad. It is possible to fix the issue by cleaning and re-soldering the fob but you should also have a spare in case it does not work.
Circuitry
If the key fob buttons function, the circuit board inside your remote might be dirty. The issue can be solved by a thorough inspection. Broken cases and water are the most frequent causes of dirty boards. A broken case allows water and other debris to enter and short circuit the electronics. Water can also destroy pins and small connectors on the board called via's.
If you're able to open up your key fob, and you're not afraid of a little mess, we can take off the buttons and solder new ones in their place. Also, it's worth checking the connections between battery terminals. They can become very dirty and if they're loose the buttons may not work or may even remain in their down position. Soldering the terminals and buttons back in their place is generally all it takes to restore keys that are not in working order.
Non-Remote transponder chips
The sealed non-remote chips are more durable than remote fobs. However, they are susceptible to breaking if a hole is drilled in them or if a car door handle or lawnmowers is pushed over them. The majority of non-remote transponder chip failures could be attributed to a blown fuse.
If you're able to remove the sealed key fob and can tolerate the mess, you can remove the circuit board and examine the fuse with an instrument to verify diode function. If you're not comfortable with this, visit your local Oreilly or hardware store and use their RF frequency tester. This will inform you whether the key fob transmits an RF signal.
Programming
Key fobs aren't indestructible and are susceptible to damage through a variety of causes. They may lose their connection with the receiver inside your vehicle due to shocks or a low battery, which calls for the reprogramming. A professional auto locksmith or a main dealer can reprogram your key fob to get it back up and running. If resetting or fixing the keyfob is not working it is possible to replace it.