How to Fix a Key Fob That isn't Working
If your key fob isn't functioning A few easy steps can fix it. The first step is to make sure that it's not your backup remote.
If your backup remote is unable to unlock and lock the doors of your vehicle, it is likely that the primary remote isn't functioning. key repair for car for car remote key failure are battery or circuitry issues.
Battery
The battery in a key fob can wear out over time. It is relatively easy to change out a battery, although it is crucial to ensure you choose the correct type; you can look in the owner's manual or talk to the manufacturer's dealer to find out the kind of battery you require. It's recommended to examine the battery compartment with care, as dead batteries sometimes leak harmful chemicals that can damage the remote. If changing the batteries doesn't solve the problem, it may be that there are other issues that require attention by a professional. If the buttons are damaged or stuck, for example it could be necessary to disassemble the remote and rework each component. You could also try reprogramming your car to recognize the new key fob.
Buttons
Key fobs may become dirty and worn-out from repeated use. This is not uncommon however, it can cause buttons to stop working or require a long press to function. This can be extremely frustrating especially if you're away from home and you need to start your vehicle. Fortunately, even worn out or damaged buttons can be fixed with a little time and some of the materials you might already have in the house.
First, check that the batteries are charged correctly and that the indentation on the back of the button is filled. Then, carefully open the remote and look at the circuit board. Look for evidence of rust, or other signs the buttons have been damaged or worn. For example, conductive paint may be missing. Use a Q-tip dipped into rubbing alcohol to gently clean any membrane contact that has worn-out or where conductive painting is missing. Do not rub too vigorously as this can damage the conductive paint, and block the button from firing when you press it.
Check the battery connector terminals for loose solder connections. If this is the case, connecting them back can bring back function to the button. You can apply the same method to restore functionality to any other loose connection within the fob.
If any of the rubber buttons on the front of the keyfob are not functioning or require to be pressing very hard the graphite disks on the back of the button might have worn out and need to replaced. This can usually be done by rubbing a pencil on the disks, which should bring the button back to working.
If none of these solutions work or you are unable to get the button to respond when you press it hard, it could be that the circuitry is failing. It is possible to fix this issue by cleaning and re-soldering the fob, but you should have an extra in case it does not work.
Circuitry
The circuit board of your remote control may be dirty regardless of whether the buttons on the key fob are working or not. A very thorough inspection will usually resolve this problem. Broken cases and water are the most frequent causes of boards that are dirty. A damaged case can let water and other debris to get into the circuit board, causing it to short out. Water can also destroy pins and connectors that are small on the board, which are known as via's.
If you're handy enough to open your key fob, and you're not afraid of some mess, we can take off 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 function properly or become stuck in their down position. Soldering the terminals back to their original positions is often enough to restore a non-working fob back to working.
Non-Remote transponder chips
Sealed non-remote transponder chip are more durable than the remote fobs that contain them but they can be broken by a hole being made in them or pushed over by a lawnmowers blade or door handle for a car. Most of the time non-remote transponder chip malfunctions can be attributed to an exploded fuse.
If you're handy enough to open up the sealed key fob and are willing to put up with the mess, you can take off the circuit board and check the fuse using a multimeter for proper diode function. If you're not confident doing this, visit your local hardware store or Oreilly's, and they will usually have an radio frequency tester that can determine if the key fob is sending signals.
Programming
Key fobs take many abuses and aren't completely indestructible. They may lose their connection to the receiver in your car due to shock or low battery, requiring the reprogramming. A professional auto locksmith or main dealer will be able to reprogram your key fob and get it back up and running. If resetting or fixing your keyfob does not work it may be necessary to replace it.