How to Fix a Key Fob That isn't Working
If your key fob doesn't work, you can fix it by following a few simple steps. The first step is to make sure it's not the backup remote.
If your backup remote cannot unlock and lock the doors of your vehicle, it is likely that the main remote isn't working. The most common causes for key problems with your car remote are issues with the circuitry or battery.
Battery
The battery in the key fob may get worn out over the course of time. It is quite simple to change out the battery, however it is important to ensure that you choose the correct type that you can refer to your owner's manual, or contact the dealer for the manufacturer to find out the kind of battery you need. It's recommended to inspect the battery compartment carefully since dead batteries may release caustic chemicals that could damage the remote. If changing the batteries does not solve the problem it could be because there are other issues that require professional attention. If buttons are broken or stuck, for example, it may be necessary disassemble the remote and rework each component. You can 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 uncommon for buttons to stop working, or to require a hefty push to make them work. This can be a huge hassle especially if you're away from home and need to start your car. Even worn-out or malfunctioning buttons can be fixed with a bit of time and the 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. Check for G28 Car Keys of rust or other signs the buttons are damaged or worn out. For instance, conductive paint may be missing. Use a Q-tip, dipped in alcohol to gently clean any membrane contact that is worn out or where conductive paint is missing. Be careful not to rub too hard, because this could damage the conductive paint and block the button firing when it is pressed.
Check the battery connector terminals carefully for any loose solder connections. Soldering them back into place will restore the button's functionality in the event that this is the case. The same method can be used to restore functionality to any other loose connections in the fob.
If any of the rubber buttons located at the front of the keyfob are not working or need to be pressing extremely hard, the graphite disks at the back of the button may have worn out and will need to replaced. This can usually be done by rubbing a pencil on the disks, which should bring the button back to its original state.
If none of these solutions work or you cannot get the button to respond when pressed hard, it is possible that the circuitry has failed. This can sometimes be repaired with a quick clean and replacing the solder, but it is ideal to have a spare fob on hand in the event that this method fails for you.
Circuitry
Whether or not the key fob buttons function the circuit board that is inside your remote may be dirty. A thorough inspection will usually resolve this issue. Broken and damaged cases are the most frequent causes of boards that are dirty. A damaged case could allow water and other debris to get into the circuit board, which can cause it to short. Water can also eat away at pins and connectors on the board, which are known as via's.
If you're handy enough to open your key fob and aren't afraid of a little mess, we can take off the buttons and then solder new ones in their place. It's also worth checking the connections between the battery terminals. If they are loose, the buttons may not function or get stuck in their down position. Soldering terminals and buttons back to their original positions is often enough to restore a non-working fob back to working.
Non-Remote transponder chips
Sealed non-remote transponder chips are much more durable than the remote fobs that have them but they can be cracked by a hole drilled into them or run over by a lawnmowers blade or car door handle. Failures of the fuse are typically the cause of non-remote chip failures.
If you're not comfortable opening the key fob, you can remove the circuitboard and use a multimeter to determine if the diode is operating properly. If you're unsure about doing this, head to your local hardware store or Oreilly's, and they'll usually have a radio frequency tester that can tell you whether the key fob is sending signals.
Programming
Key fobs are not indestructible and can be damaged through a variety of causes. They may lose their connection with the receiver inside your vehicle because of shocks or a low battery, which calls for reprogramming. A professional auto locksmith or dealer can reprogram your key fob and get it working again. In the rarer case that resetting and fixing your key fob isn't working, it could be time to replace it entirely.