How to Fix a Key Fob That isn't Working
If your key fob does not work then you can fix it by following some simple steps. The first step is to make sure that it's not the backup remote.
If your backup remote is unable to unlock and lock the doors of your vehicle, it is most likely that the primary remote isn't functioning. The majority of car remote key malfunctions are caused by battery or circuitry problems.
Battery
The battery in a key fob can wear out over time. It is quite simple to replace a battery, although it is essential to ensure you choose the correct type; you can look in your owner's manual or contact the dealer for the manufacturer to determine the type of battery you need. It is also a good idea to examine the battery compartment thoroughly, as dead batteries sometimes leak harmful chemicals that can cause damage to the remote. If replacing the batteries doesn't solve the issue it could be because there are other issues that require professional attention. For instance, if the buttons appear stuck or broken It may be necessary to disassemble the remote and rebuild its components. You could also try reprogramming the vehicle to recognize the new key fob.
Buttons
Key fobs can become filthy and worn out due to frequent use. This is not unusual however it can cause buttons to cease functioning or require a difficult press to get them to work. This can be frustrating especially when you're away from home and need to start your car. Even worn-out or malfunctioning buttons are often fixable with a little effort and materials 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 look over the circuit board. Check for signs of rust or other indications that the buttons have been damaged or worn. For example, conductive paint may be missing. Then, using a Q-tip dipped in alcohol to gently clean any membrane contacts that are worn or have conductive paint missing. Do not rub too vigorously as this can damage the conductive paint and prevent the button from firing when pressed.
Check the battery connector terminals carefully for any loose solder connections. If this is the case, simply soldering them back in place can restore functionality to the button. The same procedure can be used to restore function to any loose connections within the fob.
Finally, if any of the rubber buttons on the front of the key fob have stopped working or require a difficult press to function, it is likely that the graphite disks at the back of the button are wearing down and need to be replaced. This can usually be done by rubbing a pencil over the disks, which should bring the button back to life.
If all of this doesn't help, or if the button does not respond to a firm press It could be the case that the circuit board itself is damaged. key car repair is possible to fix this by cleaning and re-soldering your fob but you should also have another spare in case it doesn't work.
Circuitry
Whether or not the keys fob buttons are functioning, the circuit board inside the remote could be dirty. A very thorough inspection will usually resolve this issue. The most common causes of dirty circuit boards are water and damaged cases. A damaged case can let water and other debris to enter the circuit board, which can cause it to short out. Water can also eat away at pins and connectors that are small on the board, referred to as via's.
If you're able to open up your key fob and don't mind a little mess, we can remove the solder from the buttons and put new ones in their place. It's also worth examining the battery terminal connections. They can get very dirty and if they're loose the buttons may not work or may even remain in their down position. Soldering the terminals and buttons into place is usually enough to bring a non-working fob to working.
Non-Remote transponder chips
Sealed non-remote transponder chips are more durable than the remote fobs that contain them but they can still be broken by a hole being made in them or pushed over by a lawnmower or car door handle. The majority of non-remote transponder chip failures could be attributed to 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 test the fuse using a multimeter for proper diode function. If you're not sure with this, visit your local Oreilly or hardware store and test their RF frequency tester. This will inform you whether the key fob is sending signals.
Programming
Key fobs are subject to lots of abuse and aren't completely indestructible. They can lose their pairing to the car's receiver due to shock or a low battery, which requires the reprogramming. A professional auto locksmith, or the main dealer, can reprogram your keyfob to get it functioning again. If resetting or replacing the keyfob is not working, you may need to replace it.