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 can lock and unlock the doors of your car, then it is most likely that the primary remote isn't working. The most common causes of key problems with your car remote are issues with the circuitry or battery.
Battery
It is not unusual for the battery in the key fob for cars to get worn out. It is easy to replace a battery. However, it is important to select the right kind. You can refer to the owner's manual or contact the manufacturer to inquire about the right kind. It is also essential to check the battery compartment, since dead batteries can leak toxic chemicals that could damage the remote. If replacing the battery does not fix the problem, there may be other issues requiring professional attention. If the buttons are stuck or broken, for example it could be necessary to take the remote apart and rework each component. You can also try reprogramming your car to recognize the new key fob.
Buttons
Key fobs may become filthy and worn out due to frequent use. This is not unusual however, it can cause buttons to stop working or require a very hard press for them to work. car key fob repair can be frustrating, especially when you are away from home and you need to turn on your car. Fortunately, even worn out or damaged buttons can be fixed with a bit of time and some of the materials you may already have around the house.
First, make sure that the batteries have been correctly placed and that the indentation at the back of the button is filled. Then, carefully remove the remote and inspect the circuit board. Check for signs of rust or other signs the buttons have been damaged or worn out. For example the paint that conducts electricity could be missing. Use a Q-tip, dipped in rubbing alcohol to gently clean any membrane contact that has worn out or where conductive painting is missing. Be careful not to rub too hard, as this can erode the conductive paint and block the button firing when it is pressed.
Check the battery connector's terminals carefully for any loose solder connections. Soldering them back to their original position will allow the button to function again in the event that this is the situation. You can use the same method to restore functionality to any other loose connection within the fob.
If any of the rubber buttons at the front of the keyfob isn't working or require being pressing extremely hard the graphite disks at the back of the button could have worn out and will need to replaced. This is usually done by rubbing a pencil on the disks. This should bring the button back to life.
If none of these solutions work, or if you still are unable to get the button to respond when pressed hard, it is possible that the circuitry has failed. It is possible to fix this with a quick clean and refitting, but it's best to have an extra fob available in the event this method doesn't work for you.
Circuitry
The circuit board of your remote control may be dirty, regardless of whether the buttons on the key fob work or not. A very thorough inspection is often enough to resolve this issue. Broken cases and water 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 get through pins and vias, which are the tiny connectors on the board.
If you're able to open up your key fob and don't mind some 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. They can become extremely dirty and if they're loose the buttons might not work or may even remain in their down position. Soldering the terminals back into place is usually enough to return a malfunctioning fob to a working condition.
Non-Remote transponder chips
Sealed non-remote transponder chips are much more durable than the remote fobs that contain them but they can be damaged by a hole that is drilled into them or run over by a lawnmowers or car door handle. Fuse failures are usually to blame for non-remote chip failures.
If you are not comfortable opening the key fob, you may remove the circuitboard and use a multimeter to verify that the diode is operating properly. If you're unsure about doing this, visit your local hardware store or Oreilly's and they'll usually have an RFID frequency tester that can determine whether the key fob is sending signals.
Programming
Key fobs are subject to a lot of abuse and aren't completely indestructible. They may lose their connection with the receiver inside your vehicle because of shocks or a low-battery, which requires reprogramming. A professional auto locksmith or main dealer can reprogram the keyfob to get it working again. If, in the unlikely event that resetting and fixing your key fob doesn't work it may be time to replace it all over again.