How to Fix a Key Fob That isn't Working
If your key fob doesn't work and you're not sure why, you can fix it with some simple steps. First, ensure that it's not the backup remote.
If the backup can lock and unlock your car doors then there's a likely issue with the main remote. Most car remote key failures result from battery or circuitry problems.
Battery
The battery in a key fob can wear out over time. It is easy to replace batteries. However it is essential that you choose the right kind. You can consult your owner's manual or call the manufacturer to determine the right kind. It is also a good idea to examine the battery compartment with care because dead batteries can leak caustic chemicals that can harm the remote. If replacing the battery does not fix the problem there could be other issues that require professional attention. 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 vehicle to recognize the new key fob.
Buttons
Through repeated use, key fobs can become worn and dirty. It is not uncommon for buttons to cease working, or to require a hefty press to make them work. car key fob repairs can be a hassle, especially when you are away from your home and you need to start your car. Fortunately, even worn out or damaged buttons can be fixed with a little time and some of the materials you may already have around the home.
First, check that the batteries have been correctly installed and that the indentation on the back of the button has been filled. Then, open the remote with care and inspect the circuit board. Check for indications of rust or other signs the buttons are damaged or worn out. For example there could be conductive paint missing. Use a Q-tip that has been dipped in alcohol to gently clean any membrane contact that has become damaged or has conductive paint missing. Do not rub too vigorously as this can damage the conductive paint and prevent the button from firing when pressed.
Examine the battery connector's terminals carefully for any loose solder connections. Soldering them back in place will allow the button to function again If this is the situation. The same method can be used to restore functionality to any other loose connections within 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 on the back of the button may have worn out and will require replacement. This can usually be done by rubbing a pencil on the disks, which should bring the button back to its original state.
If none of this is useful, or if the button still doesn't respond to a firm press, then it may be because the circuit board has gone bad. It is possible to fix this issue by cleaning and re-soldering the fob but you should also have an extra in case it doesn't work.
Circuitry
The circuit board inside your remote control may be dirty regardless of whether the buttons on the key fob work or not. This problem can be resolved by a thorough inspection. The most common causes for dirty circuit boards are water and damaged cases. A damaged case could allow water and other debris to enter the circuit board, which can cause it to short. Water can also damage pins and vias, which are small connectors that are found on the board.
If you are handy enough to open your key fob and you don't mind making a mess, we can take the buttons out of their sockets and put in new ones. It's also worth checking the battery terminal connections. If they're loose, the buttons may not function or get stuck in their down position. Soldering the terminals, and putting the button back in place is usually all that's required to return the key fob that is not working to functioning condition.
Non-Remote transponder chips
The non-remote chips sealed in a sealed case are more durable than remote fobs, but they are susceptible to breaking when a hole is made in them or in the event that a door handle of a car or lawnmowers is pushed over them. Most of the time, non-remote transponder chip failures can be attributed to an exploded fuse.
If you're handy enough to remove a key fob that is sealed and are willing to put up with the mess, you can remove the circuit board and examine the fuse with an instrument to verify diode function. If you don't feel comfortable with this, go to your local Oreilly or hardware store and utilize their RF frequency tester. This will inform you whether the key fob is sending signals.
Programming
Key fobs take lots of abuse and aren't indestructible. They can lose their pairing with the receiver inside your vehicle due to shocks or low-battery, which requires the reprogramming. A professional auto locksmith or main dealer can reprogram your keyfob and get it functioning again. If resetting or replacing your key fob fails it may be necessary to replace it.