How to Fix a Key Fob That isn't Working
If your key fob isn't working There are a few simple steps that can be taken to fix it. The first step is to be 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 main remote. Most problems with car remote keys result from battery or circuitry problems.
Battery
It is not unusual for the battery inside a car key fob to degrade. It is easy to replace the battery. However it is essential that you choose the right type. You can check the owner's manual or contact the manufacturer to determine the correct type. It is also crucial to check the battery compartment, as dead batteries can leak toxic chemicals that could damage the remote. If changing the batteries does not solve the issue, it may be that there are other issues that require attention from a professional. If the buttons are broken or stuck, for example it could be necessary to take the remote apart and rework each component. You could also try reprogramming your car to recognize the new key fob.
Buttons
Due to repeated use, key fobs could become worn and dirty. It is not uncommon for buttons to stop working, or to require a hefty press to make them work. This can be very frustrating 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 just a bit of time and a few items you have in the home.
First, ensure that the batteries are charged correctly and that the indentation on the back of the button is filled. Take the remote apart and look over the circuit board. Examine for signs of rust or other indications that the buttons are worn or damaged, like missing conductive paint. Use a Q-tip dipped in alcohol to gently clean any membrane contacts that are damaged or have conductive paint missing. Don't rub too hard in order to damage the conductive paint and stop the button from firing when pressed.
Also, make sure to inspect the battery connector's terminals for an unattached solder connection. Soldering them back in place can restore the button's functionality If this is the case. The same process can be used to restore function to any other loose connections in the fob.
If any of the rubber buttons located at the front of the keyfob are not working or require being press extremely hard the graphite disks on the back of the button may have worn out and need to replaced. You can usually do this by rubbing a pencil over the disks. This will bring the button back to life.
If none of these solutions work, or if you still cannot get the button to respond when you press it hard, it is possible that the circuitry has failed. It is possible to fix this issue by cleaning and re-soldering the button but you should also have another spare in case it does not work.
Circuitry
If the key fob buttons function the circuit board in the remote could be dirty. A thorough examination is usually enough to fix this issue. Broken and damaged cases are the most frequent causes of dirty boards. A broken case can allow water and other debris to get into the circuit board, causing it to short out. Water can also eat through pins and vias, which are the tiny connectors that are found on the board.
If you're able to open your key fob, and you're not afraid of making a mess, we can de-solder the buttons and then solder new ones in their place. It's also worth looking at the battery terminal connections. If they are loose, the buttons might not work or even become stuck in their down position. Soldering terminals and buttons back to their original positions is often enough to return a malfunctioning fob to working.
car key fob repair -Remote transponder chips
The sealed non-remote chips are more durable than remote fobs, but they are susceptible to cracking when a hole is made in them, or in the event that a door handle of a car or lawnmowers plows over them. The failure of the fuse is usually the cause of non-remote chip failures.
If you're handy enough to open up a key fob that is sealed and are able to bear the mess, you can take off the circuit board and examine the fuse using an instrument to verify diode function. If you're not confident doing this, go to your local hardware store or the Oreilly's and they'll usually have an RF frequency tester that will determine if the key fob is sending a signal.
Programming
Key fobs are not indestructible and can be damaged through a variety of causes. They can lose their pairing to the car's receiver due to shock or a low battery, which calls for the reprogramming. A professional auto locksmith or a main dealer will be able to reprogram your key fob and get it functioning again. In the event that resetting and fixing your key fob doesn't work it could be the time to replace it entirely.