How to Fix a Key Fob That isn't Working
If your key fob won't work and you're not sure why, you can fix it with some simple steps. The first step is to make sure that it's not your backup remote.
If the backup is able to lock and unlock your car door, then there's a likely issue with the main remote. The majority of car remote key malfunctions are caused by battery or circuitry problems.
Battery
It is not unusual for the battery in a car key fob to wear out. It is quite simple to replace the battery, however it is important to ensure that you select the correct one and you can consult your owner's manual or contact the dealer of the manufacturer to determine the type of battery you require. It's also a good idea to inspect the battery compartment thoroughly since dead batteries may release caustic chemicals that could damage the remote. If changing the battery doesn't solve the issue, there may be other issues requiring professional attention. If buttons are stuck or broken, for example it might be necessary to disassemble the remote and rework each component. It is also possible to reprogramme the vehicle to recognize the new fob.
Buttons
Key fobs may become dirty and worn-out from repeated use. This is not atypical, but it can cause buttons to cease functioning or require a difficult press to get them to work. This can be a hassle especially when you're away from home and have to switch on your car. Even worn-out or malfunctioning buttons can be fixed with a bit of time and the tools you already have at home.
First, check that the batteries are up correctly and that the indentation on the back of the button is filled. Take the remote apart and inspect the circuit board. Check for indications of rust or other indications that 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 damaged or where conductive paint is missing. Be careful not to rub too hard, since this could cause damage to the conductive painting and prevent the button firing when it is pressed.
Also, be sure to check the battery connector terminals for a loose solder connection. If this is the case, simply soldering them back in place can restore function to the button. You can use the same process to restore functionality to any other loose connection inside the fob.
If any of the rubber buttons located at the front of the keyfob aren't functioning or require to be pressed extremely hard the graphite disks on the back of the button may have worn out and will need to replaced. This can be done by rubbing a pencil on the disks. This should bring the button back to its original state.
If none of this is useful, or if the button doesn't respond to a firm press, then it may be that the circuit board itself has gone bad. It is possible to fix the issue by cleaning and re-soldering your fob however, you should have another spare in case it doesn't work.
Circuitry
The circuit board in your remote control may be dirty regardless of whether the buttons on the key fob work or not. A thorough examination is usually enough to fix this problem. Broken cases and water are the most common causes of boards that are dirty. A damaged case allows water and other debris to get in and short out the electronic components. car key fob repair service can also eat through pins and vias, which are the tiny connectors found on the board.
If you're skilled enough to open your key fob, and don't mind making a mess, we can remove the buttons from their sockets and solder in new ones. Also, you should check the connections between battery terminals. If they're loose, the buttons may not function properly or become stuck in their down position. Soldering terminals and buttons 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 chips are more durable than remote fobs that contain them but they can still be cracked by a hole that is drilled into them or over by a lawnmowers blade or car door handle. The failure of the fuse is usually to blame for non-remote chip failures.
If you're handy enough to remove a key fob that is sealed and can tolerate the mess, you can remove the circuit board and examine the fuse with a multimeter for proper diode function. If you're unsure about doing this, visit your local hardware store or Oreilly's and they'll usually have a RFID frequency tester that can tell you whether the key fob is transmitting a signal.
Programming
Key fobs endure lots of abuse and aren't impervious to damage. 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 main dealer can reprogram the keyfob and get it up and running again. If resetting or fixing your key fob fails, you may need to replace it.