How to Fix a Key Fob That isn't Working
If your key fob won't work, you can fix it with a few simple steps. The first step is to be 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 main remote isn't functioning. The most common causes for key problems with your car remote are issues with the circuitry or battery.
Battery
The battery inside the key fob may get worn out over the course of time. It is simple to replace a battery. However it is essential to select the right type. You can refer to your owner's manual or call the manufacturer to find out the right type. It is also essential to check the battery compartment as batteries that are not working properly can release caustic chemicals which can damage the remote. If changing the battery doesn't solve the issue there could be other issues that require professional attention. For instance, if buttons seem stuck or broken, it may be necessary to disassemble the remote and rework its components. You can also try reprogramming your car to recognize the new key fob.
Buttons
Key fobs can become dirty and worn-out from repeated use. This is not atypical, but it can cause buttons to stop working or require a difficult press to get them to function. This can be very frustrating, especially when you are away from your home and have to start your car. Even worn-out or malfunctioning buttons can be fixed with a bit of time and materials you already have at home.
First, check that the batteries are properly installed and that the indentation at the back of the button has been filled. Then, carefully remove the remote and inspect the circuit board. Check for indications of rust or other indications that the buttons are damaged or worn. For instance, conductive paint may be missing. Use a Q-tip that has been dipped in alcohol to gently clean any membrane contacts that are damaged or have conductive paint missing. Do not rub too vigorously in order to damage the conductive paint and stop the button from firing when pressed.
Also, carefully check the battery connector's terminals for an unattached solder connection. Soldering them back into place will restore the button's functionality if this is the situation. You can follow the same method to restore functionality to any other loose connection inside the fob.
In the end, if any of the buttons made of rubber on the front of the key fob have stopped functioning or require a long press to function it is likely that the graphite disks that are on the back of the button are deteriorating and require replacement. You can do this by rubbing a pencil over the disks. This will bring the button back to life.
If none of these solutions work or you cannot get the button to respond when you press it hard, it could be that the circuitry has failed. It is possible to fix this by a quick clean and re-soldering, but it is best to have an extra fob available in the event this method does not work for you.
Circuitry
Whether or not the key fob buttons function the circuit board in your remote may be dirty. A very thorough inspection is often enough to resolve this issue. The most common causes for dirty circuit boards are water and damaged cases. A broken case can allow water and other debris to get into the circuit board, which can cause it to short out. Water can also destroy pins and connectors that are small on the board, which are known as via's.
If you're able to open your key fob, and you don't mind making some mess, we can take the buttons out of their sockets and then solder new ones. It's also worth checking the connections between battery terminals. They can become very dirty and if they're loose, the buttons may not work or even stay in their down position. Soldering the terminals and button's back in place is usually all it takes to restore keys that are not in working 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 chip malfunctions could be attributed to a blown fuse.
If you're not confident opening the key fob, you can remove the circuitboard and utilize a multimeter to check that the diode is functioning correctly. If you're not comfortable doing this, head to your local hardware store or Oreilly's, and they usually have a RFID frequency tester that can let you know if the key fob is transmitting a signal.
Programming
Key fobs are subject to many abuses and aren't impervious to damage. They can break their connection with the receiver inside your vehicle because of shocks or a low-battery, which requires the reprogramming. A professional auto locksmith, or the main dealer, can reprogram your keyfob to get it working again. If, in repair car key that resetting and repairing your key fob fails it could be the time to replace it completely.