How to Fix a Key Fob That isn't Working
If your key fob won't work, you can fix it with just a few steps. First, check to make sure it's not the backup remote.
If your backup remote is unable to unlock and lock the doors of your vehicle, it is likely that the primary remote is not working. The most frequent causes of key malfunctions for car remotes are circuitry or battery issues.
Battery
The battery inside the key fob could be worn out over time. It is simple to replace the battery. However it is essential that you use the correct type. You can consult your owner's guide or contact the manufacturer to find out the right kind. It is recommended to examine the battery compartment carefully because dead batteries can leak harmful chemicals that can cause damage to the remote. If changing the battery doesn't fix the problem, there may be other issues requiring professional attention. If the buttons are stuck or broken for instance it might be necessary to disassemble the remote and rework each component. You can also try reprogramming the vehicle to recognize the new key fob.
Buttons
From frequent use, key fobs could become worn and dirty. This is not atypical however, it can cause buttons to stop functioning or require a hard press for them to work. This can be a hassle especially when you're away from home and need to start your car. Fortunately, even worn out or broken buttons can usually be fixed with a bit of time and some of the materials you may already have around the house.
First, make sure the batteries are properly charged and that the indentation on the back of the button is filled. Then, carefully open up the remote and examine the circuit board. Check for signs of corrosion or other indications that buttons are worn out or damaged, such as missing the conductive paint. Use a Q-tip, dipped in rubbing alcohol to gently clean any membrane contact that is worn out or has conductive paint missing. Avoid rubbing too hard, since this could cause damage to the conductive paint and block the button from firing when it is pressed.
Check the battery connector's terminals for loose solder connections. If this is the case, reconnecting them could restore functionality 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 isn't functioning or require to be press extremely hard the graphite disks on the back of the button may have worn out and need to replaced. This can usually be done by rubbing a pencil across the disks, which should bring the button back to life.
If none of this is useful or if the button still does not respond to a firm press, then it may be because the circuit board is damaged. It is possible to fix the issue by cleaning and re-soldering the fob but you should also have a spare in case it does not work.
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 issue. Broken cases and water are the most common causes of dirty boards. key fob repairs damaged case can let water and other debris into the circuit board, which can cause it to short. Water can also eat away at pins and connectors that are small on the board called via's.
If you're handy enough to open up your key fob and don't mind making a mess, we can take off the buttons and then solder new ones in their place. It's also worth checking the battery terminal connections. They can become very filthy and if they're not tight enough, the buttons might not function or even stick in their down position. Soldering the terminals back to their proper positions is usually enough to return a malfunctioning fob back to working.
Non-Remote Transponder Chips
Sealed non-remote transponder chips are much more durable than remote fobs that contain them but they can be damaged by a hole that is drilled into them or run over by a lawnmowers blade or door handle for a car. Fuse failures are usually to blame for non-remote chips failures.
If you're not confident opening the key fob, you may remove the circuitboard and utilize a multimeter to determine if the diode is operating properly. If you're not comfortable with this, you can go to your local Oreilly or hardware store and test their RF frequency tester. This will inform you whether the key fob is sending an RF signal.
Programming
Key fobs take a lot of abuse and aren't impervious to damage. They can lose their pairing with the receiver in your vehicle due to shocks or low battery, which calls for changing the program. A professional auto locksmith, or a dealer in the main can reprogram your keyfob to get it functioning again. If resetting or replacing the keyfob is not working, you may need to replace it.