How to Fix a Key Fob That isn't Working
If your key fob won't work, you can fix it by following some simple steps. First, make sure that it's not your backup remote.
If the backup is able to lock and unlock your car doors, then there's a likely issue with the primary remote. car keys repair with car remote keys are caused by circuitry or battery issues.
Battery
The battery in the key fob may be worn out over time. It is simple to replace the battery. However it is crucial to select the right kind. You can consult the owner's manual or contact the manufacturer to determine the right kind. It is also essential to check the battery compartment as dead batteries can leak toxic chemicals that could damage the remote. If replacing the battery does not fix the problem there could be other issues that require attention from a professional. For instance, if buttons seem stuck or damaged it could be necessary to take the remote apart and rework its components. It is also possible to reprogramme the vehicle to recognize the new device.
Buttons
From frequent use, key fobs may wear out and become dirty. This is not atypical however it can cause buttons to cease functioning or require a difficult press to get them to function. This can be very frustrating especially when you're away from home and you need to turn on your car. Even malfunctioning or worn-out buttons are often fixable with a little time and tools you already have at home.
First, make sure that the batteries have been correctly placed and that the indentation on the back of the button is filled. Then, carefully open the remote and inspect the circuit board. Look for evidence of rust, or other signs the buttons are worn or damaged. For example there could be conductive paint missing. Use a Q-tip, dipped in rubbing alcohol to gently clean any membrane contact that has worn-out or has conductive paint missing. Be careful not to rub too hard, since this could cause damage to the conductive painting and prevent the button from firing when it is the button is pressed.
Also, be sure to check the battery connector's terminals to ensure any loose solder connections. Soldering them back to their original position will restore the button's functionality If this is the case. You can apply the same process to restore functionality to any other loose connection in the fob.
If, for instance, any of the rubber buttons on the front of the key fob stop working or require a very difficult press to function it is likely the graphite disks that are on the back of the button are wearing down and require replacement. This is usually done by rubbing a pencil across the disks. This should bring the button back to life.
If all of this doesn't help, or if the button doesn't respond to a firm press, then it may be because the circuit board has become damaged. It is possible to fix this by a quick clean and re-soldering, but it is recommended to have an additional fob on hand in the event that this method does not work for you.
Circuitry
The circuit board in the remote control could be dirty, regardless of whether the buttons on the key fob are working or not. The issue can be solved through a thorough examination. The most frequent causes of dirty circuit boards is water and damaged cases. A broken case allows water and other debris to enter and short out the electronic components. Water can also eat away at pins and connectors on the board, which are known as via's.
If you're able to open your key fob and don't mind making an mess, you can take the buttons out of their sockets and then solder new ones. Also, you should check the connections between the battery terminals. If they're loose, the buttons could not work or even become stuck in their down position. Soldering the terminals and buttons to their original positions is often enough to restore a non-working fob to working.
Non-Remote transponder chips
Sealed non-remote transponder chips are much more durable than remote fobs that have them but they can be cracked by a hole that is drilled into them or over by a lawnmowers or door handle for a car. Most of the time, non-remote transponder chip failures can be blamed on blowing fuses.
If you're not comfortable opening the key fob, you may remove the circuitboard and use a multimeter to determine if the diode is working properly. If you're unsure about doing this, go to your local hardware store or Oreilly's and they will usually have an RF frequency tester that will determine whether the key fob is sending a signal.
Programming
Key fobs endure lots of abuse and aren't completely indestructible. They may lose their connection to the receiver in your car due to shock or a low battery, requiring them to be reprogrammed. A professional auto locksmith or main dealer can reprogram your key fob and get it back functioning again. If, in the unlikely event that resetting and repairing your key fob isn't working it may be time to replace it entirely.