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 just a few steps. First, ensure that it's not the backup remote.
If your backup remote can unlock and lock the doors of your car, then it is most likely that the primary remote is not working. Most car remote key failures result from circuitry or battery issues.
Battery
The battery in the key fob could be worn out over time. It is quite simple to replace a battery, although it is important to ensure that you select the correct one; you can look in the owner's manual or talk to the dealer of the manufacturer to find out what kind of battery you require. It is also crucial to inspect the battery compartment, as batteries that are not working properly can release caustic chemicals which can damage the remote. If replacing the battery does not fix the issue there may be additional issues that require attention from a professional. If buttons are stuck or broken for instance it might be necessary to take the remote apart and rework each component. You can also try reprogramming the vehicle to recognize the new remote.
Buttons
Key fobs may become dirty and worn out from repeated use. This is not uncommon, but it can cause buttons to stop working or require a long press to work. This can be very frustrating, especially if you are away from home and need to start your vehicle. Fortunately, even worn-out or malfunctioning buttons can often be fixed with a little time and some of the materials you might already have in the house.
First, check that the batteries are correctly inserted and that the indentation at the back of the button is filled. Then, carefully open the remote and inspect the circuit board. Look for evidence of rust, or other indications that the buttons are worn or damaged. For instance, conductive paint may be missing. Utilizing a Q-tip that has been dipped in alcohol, gently clean any membrane contacts that have become worn or have conductive paint missing. Avoid rubbing too hard since this could cause damage to the conductive paint and block the button from firing when pressed.
Check the battery connector's terminals carefully for any loose solder connections. If this is the case, soldering them back in place may bring back function to the button. You can use the same procedure to restore functionality to any other loose connection in the fob.
Finally, if any of the rubber buttons on the front of the key fob stop functioning or require a long press to function it is likely the graphite disks at the back of the button are wearing out and require replacement. This is usually done by rubbing a pencil on the disks, which should bring the button back to working.
If none of these solutions work, or if you still are unable to get the button to respond when you press it hard, it could be that the circuitry is failing. This can be fixed by a quick clean and replacing the solder, but it is ideal to have a spare fob on hand in the event that this method fails for you.
Circuitry
If the keys fob buttons are functioning the circuit board in your remote might be dirty. A thorough inspection is often enough to resolve this problem. The most common causes for dirty circuit boards is water and damaged cases. A broken case can let water and other debris to enter the circuit board, causing it to short. Water can also damage pins and connectors that are small on the board, which are known as via's.
If you're handy enough to remove your key fob, and you're not afraid of some mess, we can take off the buttons and put new ones in their place. It's also worth looking at the battery terminal connections. If they are loose, the buttons might not work or even become stuck in their down position. Soldering the terminals back to their proper positions is usually enough to restore a non-working fob to a working condition.
Non-Remote Transponder Chips
Sealed non-remote transponder chips are more durable than the remote fobs they are contained in, but they can be cracked by a hole made in them or pushed over by a lawnmower or car door handle. Most of the time, non-remote transponder chips fail, and this can be blamed on a blown fuse.
If you're able to open up a sealed non-remote key fob and are able to bear the mess, you can easily remove the circuit board and test the fuse with a multimeter to ensure that it is functioning as intended. function. If you're not comfortable doing this, head to your local hardware store or Oreilly's and they usually have an RFID frequency tester that can determine if the key fob is sending a signal.
Programming
Key fobs endure a lot of abuse and aren't indestructible. They may lose their connection to the car's receiver because of shock or a low battery, which requires them to be reprogrammed. A professional auto locksmith or the main dealer, can reprogram your keyfob and get it working again. If, in remote key fob repair that resetting and repairing your key fob fails it could be the time to replace it all over again.