How to Fix a Key Fob That isn't Working
If your key fob does not work and you're not sure why, you can fix it with just a few steps. First, check to make sure it's not your backup remote.
If your backup remote is unable to unlock and lock the doors of your car, it is most likely that the primary remote is not working. Most problems with car remote keys result from circuitry or battery problems.
Battery
The battery in a key fob can be worn out over time. It is easy to replace a battery. However it is essential that you use the correct kind. You can check the owner's manual or contact the manufacturer to determine the right kind. It is also important to examine the battery compartment as dead batteries can leak toxic chemicals that could damage the remote. If changing the batteries doesn't solve the issue, it may be that there are other issues that require attention from a professional. For instance, if buttons seem to be stuck or damaged It may be necessary to take the remote apart and rework its components. You could also try reprogramming your vehicle to recognize the new key fob.
Buttons
Through repeated use, key fobs could become worn and dirty. car keying repair is not uncommon however it can cause buttons to cease working or require a very hard press for them to work. This can be a hassle especially when you're away from your home and have to turn on your car. Even malfunctioning or worn-out buttons are often fixable with a little effort and the tools you already have at home.
First, ensure that the batteries are up correctly and that the indentation on the back of the button is filled. Then, open the remote with care and examine the circuit board. Look for signs of rust or other signs the buttons are damaged or worn out. For example, conductive paint may be missing. Use a Q-tip, dipped in rubbing alcohol to gently clean any membrane contact that is damaged or where conductive painting is missing. Do not rub too vigorously as this can damage the conductive paint and prevent the button from firing when pressed.
Examine the battery connector's terminals carefully for any loose solder connections. Soldering them back into place will allow the button to function again in the event that this is the situation. The same procedure can be used to restore function to any loose connections inside the fob.
If any of the rubber buttons located at the front of the keyfob isn't working or need to be press extremely hard the graphite disks on the back of the button might have worn out and will need to replaced. You can usually do this by rubbing a pen over the disks. This should bring the button back to life.
If none of this is useful, or if the button doesn't respond to a hard push, then it may be because the circuit board is damaged. This can sometimes be repaired with a quick clean and replacing the solder, but it is recommended to have an additional fob available in the event this method fails for you.
Circuitry
Whether or not the key fob buttons are working the circuit board that is inside the remote could be dirty. A very thorough inspection will usually resolve this problem. Water and broken cases are the most common causes of dirty boards. A broken case allows water and other debris to get in and short out the electronic components. Water can also damage pins and vias, which are tiny connectors found on the board.
If you are handy enough to open your key fob, and aren't afraid of making an mess, you can remove the buttons from their sockets and then solder new ones. It's also worth looking at the battery terminal connections. If they're loose, the buttons could not function or get stuck in their down position. Soldering the terminals and buttons to their proper positions is usually enough to restore a non-working fob to a working condition.
Non-Remote transponder chips
Sealed non-remote transponder chip are more durable than the remote fobs that have them but they can be cracked by a hole made in them or pushed over by a lawnmowers blade or car door handle. Most of the time non-remote transponder chips fail, and this could be attributed to an exploded fuse.
If you're handy enough to open up a sealed non-remote key fob and can tolerate the mess, you can remove the circuit board and examine the fuse using a multimeter to ensure that it is functioning as intended. function. If you're unsure about doing this, head to your local hardware store or the Oreilly's and they'll usually have an RF frequency tester that will let you know if the key fob is sending a signal.
Programming
Key fobs take many abuses and aren't completely indestructible. 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 a dealer in the main, can reprogram your key fob and get it back functioning again. In the event that resetting and fixing your key fob fails it could be the time to replace it completely.