How to Fix a Key Fob That isn't Working
If your key fob won't work then you can fix it by following just a few steps. The first step is to make sure that it's not your backup remote.
If the backup remote is able to lock and unlock your car doors it is most likely an issue with the main remote. The majority of car remote key malfunctions are caused by circuitry or battery issues.
Battery
The battery in the key fob could get worn out over the course of time. It is simple to replace batteries. However it is crucial that you choose the right type. You can check your owner's guide or contact the manufacturer to find out the correct type. It is also a good idea to examine the battery compartment thoroughly since dead batteries may release caustic chemicals that could cause damage to the remote. If replacing the battery does not fix the issue there may be additional issues that require attention from a professional. For example, if buttons appear stuck or damaged it could be necessary to take the remote apart and rebuild its components. You could also try reprogramming your vehicle to recognize the new key fob.
Buttons
From repeated use, key fobs can wear out and become dirty. It is not unusual for buttons to cease working, or to require a long push to make them work. This can be a hassle particularly when you're away from home and you need to turn on your car. Even worn-out or malfunctioning buttons are often fixable with a bit of time and tools you already have at home.
First, check that the batteries are charged correctly and that the indentation on the back of the button is filled. Then, open the remote with care and look over the circuit board. Check for signs of corrosion or other signs that the buttons are worn or damaged, such as missing paint that is conductive. Then, using a Q-tip that has been dipped in rubbing alcohol, gently clean any membrane contacts that have damaged or where conductive paint is missing. Don't rub too hard, as this could erode the conductive paint, and block the button from firing when it is pressed.
Also, carefully check the battery connector's terminals to ensure a loose solder connection. If this is the case, connecting them back could restore functionality to the button. You can follow the same procedure to restore functionality to any other loose connection inside the fob.
If, for instance, any of the buttons made of rubber that are on the front of the key fob stop working or require a very long press to function it is likely the graphite disks that are on the back of the button are wearing down and require replacement. This is usually done by rubbing a pencil on the disks, which should bring the button back to life.
If none of these solutions work or you cannot get the button to respond when pressed hard, it is possible that the circuitry has failed. It is possible to fix the issue by cleaning and re-soldering your fob however, you should have a spare in case it does not work.
Circuitry
If the key fob buttons are working the circuit board that is inside the remote could be dirty. A very thorough inspection will usually resolve this issue. Water and broken cases are the most frequent causes of dirty boards. A broken case can allow water and other debris to enter the circuit board, causing it to short. Water can also eat through pins and vias, which are small connectors on the board.
If you are handy enough to open your key fob and aren't afraid of making a mess, we can remove the buttons from their sockets and solder in new ones. It's also worth checking the connections between battery terminals. If they're loose, the buttons could not function or get stuck in their down position. Soldering the terminals back to their original positions is often enough to return a malfunctioning fob to working.
https://www.g28carkeys.co.uk/car-key-repairs-near-me/ -Remote transponder chips
Sealed non-remote transponder chips are more durable than remote fobs that contain them but they can be broken by a hole being that is drilled into them or over by a lawnmowers blade or car door handle. The failure of the fuse is usually the cause of non-remote chip failures.
If you're able to open a sealed non-remote key fob and can tolerate the mess, you can take off the circuit board and check the fuse with an instrument to verify diode function. If you're not comfortable doing this, go to your local hardware store or Oreilly's and they will usually have a RFID frequency tester that can let you know whether the key fob sending signals.
Programming
Key fobs are not indestructible and are susceptible to damage by a variety of factors. They can lose their pairing to the car's receiver due to shock or a low battery, which calls for them to be reprogrammed. A professional auto locksmith or the main dealer can reprogram your keyfob and get it up and running again. If resetting or fixing your key fob fails, you may need to replace it.