How to Fix a Key Fob That isn't Working
If your key fob isn't working, a few easy steps can be taken to fix it. First, make sure that it's not the backup remote.
If your backup remote is unable to unlock and lock the doors of your car, it is likely that the main remote is not working. The majority of car remote key malfunctions are caused by battery or circuitry problems.
Battery
The battery in the key fob may get worn out over the course of time. It is easy to replace the battery. However, it is important to select the right kind. You can check your owner's manual or call the manufacturer to inquire about the correct type. It is also important to examine the battery compartment, as batteries that are not working properly can release caustic chemicals that can harm the remote. If replacing the battery does not fix the issue there could be other issues that require professional attention. If the buttons are stuck or broken for instance it could be necessary to disassemble the remote and rework each component. You could also try reprogramming your car to recognize the new key fob.
Buttons
Key fobs may become dirty and worn-out from frequent use. It is not unusual for buttons to stop functioning, or require a long press to get them working. This can be extremely 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 bit of time and a few materials you might already have in the home.
First, check that the batteries are charged correctly and that the indentation on the back of the button is filled. Then, carefully open up the remote and inspect the circuit board. Look for signs of corrosion or other indications that the buttons are worn or damaged, like missing conductive paint. Utilizing the Q-tip, dipped in alcohol, gently clean any membrane contacts that have become worn or where conductive paint is missing. Do not rub too vigorously in order to damage the conductive paint and prevent the button from firing when pressed.
Check the battery connector 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 apply the same procedure 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 press very hard the graphite disks on the back of the button might have worn out and will need to replaced. This can be done by rubbing a pencil across the disks, which should bring the button back to life.
If none of these solutions work or you not be able to get the button respond when you press it hard, it is possible that the circuitry is failing. It is possible to fix this issue by cleaning and re-soldering the button, but you should have an other spare in case it does not work.
Circuitry
The circuit board of the remote control could be dirty regardless of whether the buttons on the key fob function or not. A thorough examination is usually enough to fix this issue. Broken cases and water are the most common causes of dirty boards. A damaged case could allow water and other debris to enter the circuit board, causing it to short. Water can also get through pins and vias, which are small connectors on the board.
If you're able to open your key fob and don't mind making a mess, we can remove the buttons from their sockets and put in new ones. It's also worth checking the connections between the battery terminals. They can become extremely filthy and if they're not tight enough, the buttons may not work or may even remain in their down position. Soldering the terminals and button's back in place is usually all that's required to return keys that are not in functioning condition.
Non-Remote transponder chips
The sealed non-remote chips are more durable than remote fobs, but they can be cracked when a hole is made into them or in the event that a door handle of a car or lawnmower runs over them. Failures of the fuse are typically to blame for non-remote chips failures.
If you're not comfortable opening the key fob, remove the circuitboard and utilize a multimeter to check that the diode is operating correctly. If you're not comfortable with this, you can visit 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 endure a lot of abuse and aren't indestructible. They may lose their connection to the receiver in your car because of shock or a low battery, which requires the reprogramming. A professional auto locksmith or dealer will be able to reprogram your key fob to get it back up and running. If resetting or fixing your key fob fails it may be necessary to replace it.