How to Fix a Key Fob That isn't Working
If your key fob doesn't work, a few easy steps can fix it. The first step is to be sure it's not the backup remote.
If the backup can lock and unlock your car door, it is most likely an issue with the main remote. The most common causes for key malfunctions for car remotes are battery or circuitry issues.
Battery
It is not unusual to find a battery on a key fob for cars to get worn out. It is relatively easy to change out batteries, but it is essential to ensure you use the right type; you can look in the owner's manual or talk to the dealer for the manufacturer to determine the type of battery you require. how to repair car key lock is recommended to examine the battery compartment carefully because dead batteries can leak harmful chemicals that can cause damage to the remote. If replacing the batteries doesn't solve the problem, it may be that there are other issues that require attention from a professional. If buttons are stuck or broken for instance, it may be necessary disassemble the remote and rework each component. You can also try reprogramming the vehicle to recognize the new key fob.
Buttons
Key fobs can become filthy and worn out due to frequent use. It is not uncommon for buttons to cease working, or to require a hefty press to get them working. This can be very frustrating particularly if you're away from home and you need to start your car. Even malfunctioning or worn-out buttons are often fixable with a little effort and tools you already have at home.
First, make sure the batteries are charged correctly and that the indentation on the back of the button is filled. Then, carefully open the remote and examine the circuit board. Examine for signs of rust or other signs the buttons have been damaged or worn out. For example there could be conductive paint missing. Use a Q-tip that has been dipped in rubbing alcohol to gently clean any membrane contact that has become damaged or where conductive painting is missing. Don't rub too hard as this can damage the conductive paint and prevent the button from firing when pressed.
Check the battery connector's terminals for loose solder connections. Soldering them back into place can restore the button's functionality in the event that this is the case. The same process can be used to restore function to any loose connections inside the fob.
If any of the rubber buttons on the front of the keyfob are not functioning or require to be pressed very hard the graphite disks on the back of the button might have worn out and need to replaced. This can be done by rubbing a pencil across the disks, which will bring the button back to its original state.
If none of these solutions work, or if you still not be able to get the button respond when you press it hard, it could be that the circuitry has failed. This can be fixed with a quick clean and refitting, but it's best to have an extra fob available in the event this method fails 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. This problem can be resolved through a thorough examination. Water and broken cases are the most common causes of dirty boards. A damaged case can allow water and other debris to get in and short out the electronics. Water can also eat through pins and vias, which are small connectors that are found on the board.
If you're skilled enough to open your key fob and you don't mind making an mess, you can take the buttons out of their sockets and put in new ones. It's also worth checking the connections between battery terminals. They can become extremely dirty and if they're loose, the buttons might not work or even stay in their down position. Soldering the terminals and button's back in place is usually all that's needed to return the key fob that is not working to functioning condition.
Non-Remote Transponder Chips
Sealed non-remote transponder chips are more durable than remote fobs they are contained in, however they are still susceptible to being damaged by a hole that is made in them or pushed over by a lawnmower or door handle for a car. Most of the time, non-remote transponder chips fail, and this can be blamed on an exploded fuse.
If you're handy enough to open up a sealed non-remote key fob and are willing to put up with the mess, you can remove the circuit board and check the fuse using a multimeter for proper diode function. If you're not confident doing this, go to your local hardware store or the Oreilly's and they usually have a RFID frequency tester that can determine whether the key fob is sending a signal.
Programming
Key fobs aren't impervious to destruction and are susceptible to damage by a variety of factors. They can break their connection with the receiver in your vehicle because of shocks or a low-battery, which requires the reprogramming. A professional auto locksmith, or the main dealer can reprogram the keyfob and get it working again. If, in the unlikely event that resetting and repairing your key fob doesn't work it could be the time to replace it completely.