How to Fix a Key Fob That isn't Working
If your key fob does not work, you can fix it with some simple steps. The first step is to be sure that it's not the backup remote.
If the backup remote 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 battery or circuitry problems.
Battery
The battery in the key fob could be worn out over time. It is easy to replace a battery. However, it is important that you choose the right kind. You can check the owner's manual or contact the manufacturer to inquire about the right type. It is also crucial to check the battery compartment, since dead batteries can leak caustic chemicals that can harm the remote. If replacing the battery does not fix the problem, there may be other issues that require attention from a professional. If buttons are damaged or stuck for instance it could be necessary to disassemble the remote and rework each component. You can also try reprogramming the vehicle to recognize the new device.
Buttons
Due to frequent use, key fobs could wear out and become dirty. It is not common for buttons to cease working, or to require a hard press to get them working. This can be extremely frustrating especially if you're away from home and you need to start your car. Fortunately, even worn-out or broken buttons can usually be fixed with a little time and a few items you have in the house.
First, check that the batteries are properly charged and that the indentation on the back of the button is filled. Then, carefully remove the remote and look at the circuit board. Examine for indications of rust or other indications that the buttons have been worn or damaged. For instance, conductive paint may be missing. Use a Q-tip, dipped in rubbing alcohol to gently clean any membrane contact that has become worn out or where conductive painting is missing. Avoid rubbing too hard, because this could damage the conductive painting and prevent the button from firing when it is it is pressed.
Check the battery connector terminals for loose solder connections. If this is the case, simply soldering them back in place can restore functionality to the button. You can use the same process to restore functionality to any other loose connection inside the fob.
If any of the rubber buttons on the front of the keyfob are not working or need to be press extremely hard, the graphite disks at the back of the button may have worn out and need to replaced. This can be done by rubbing a pencil on the disks, which should bring the button back to life.
If none of this is helpful, or if the button doesn't respond to a hard press, then it may be that the circuit board itself is damaged. This can sometimes be repaired by a quick clean, and refitting, but it's recommended to have an additional fob in case this method does not work for you.
Circuitry
The circuit board of your remote control could be dirty, regardless of whether the buttons on the key fob function or not. This problem can be resolved by a thorough inspection. Broken and damaged cases are the most common causes of dirty boards. A damaged case could let water and other debris into the circuit board, which can cause it to short out. Water can also eat through pins and vias, which are small connectors found on the board.
If you're able to open your key fob and don't mind making an mess, you can remove the buttons from their sockets and solder in new ones. It's also worth looking at the battery terminal connections. They can become very dirty and if they're loose, the buttons might not work or even stay in their down position. Soldering the terminals, and putting the button back in place is usually all that's required to return keys that are not in working order.
Non-Remote Transponder Chips
The non-remote chips that are sealed are more durable than their remote fobs, but they are susceptible to breaking in the event of a hole being drilled in them or if a car door handle 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 the sealed key fob and are willing to put up with the mess, you can remove the circuit board and test the fuse using an instrument to verify diode function. If car key repair shop near me about doing this, go to your local hardware store or Oreilly's and they will usually have an RF frequency tester that will tell you if the key fob is 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 receiver in your car due to shock or low battery, which requires the reprogramming. A professional auto locksmith or dealer can reprogram your key fob and get it functioning again. If resetting or repairing your key fob fails it is possible to replace it.