How to Fix a Key Fob That isn't Working
If your key fob isn't functioning A few easy steps can be taken to fix it. The first step is to be sure it's not the backup remote.
If the backup remote is able to lock and unlock your car doors then there is likely an issue with the main remote. The most common causes of key malfunctions for car remotes 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 simple to replace the battery. However, it is important that you choose the right type. You can refer to the owner's manual or contact the manufacturer to determine the right kind. It is recommended to inspect the battery compartment thoroughly, as dead batteries sometimes leak caustic chemicals that can damage the remote. If replacing the batteries doesn't solve the problem it could be that there are other issues that require attention from a professional. If the buttons are damaged or stuck, for example it could be necessary to take the remote apart and rework each component. You could also try reprogramming the vehicle to recognize the new fob.
Buttons
Key fobs can become dirty and worn-out from frequent use. This is not unusual however, it can cause buttons to stop functioning or require a long press to work. This can be very frustrating especially when you're away from your home and need to switch on your car. Fortunately, even worn out or broken buttons can usually be fixed with a bit of time and some of the materials you have in the house.
First, make sure that the batteries are properly installed and that the indentation on the back of the button is filled. Take the remote apart and inspect the circuit board. Examine for indications of rust or other signs the buttons have been damaged or worn. For example there could be conductive paint missing. Then, using a Q-tip dipped in rubbing alcohol, gently clean any membrane contacts that have worn or where conductive paint is missing. Avoid rubbing too hard since this could cause damage to the conductive paint and stop the button firing when the button is pressed.
Also, carefully check the battery connector terminals for a loose solder connection. If this is the case, simply connecting them back may restore function to the button. You can follow the same process to restore functionality to any other loose connection in the fob.
Finally, if any of the buttons made of rubber on the front of the key fob aren't working or require a hard press to work it is likely the graphite disks that are on the back of the button are wearing down and need to be replaced. This can usually be done by rubbing a pencil across the disks, which will bring the button back to working.
If all of this doesn't help, or if the button still doesn't respond to a hard push It could be the case that the circuit board itself is damaged. It is possible to fix this by a quick clean and re-soldering, but it is ideal to have a spare fob in case this method doesn't work for you.
Circuitry
The circuit board inside the remote control could be dirty regardless of whether the buttons on the key fob work or not. The issue can be solved by a thorough inspection. Broken and damaged cases are the most frequent causes of boards that are dirty. A damaged case could let water and other debris 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 skilled enough to open your key fob, and you don't mind making some mess, we can remove the buttons from their sockets and solder in new ones. Also, you should check the connections between the battery terminals. They can become very filthy and if they're not tight enough, the buttons may not work or even stay in their down position. Soldering the terminals and buttons back in their place is generally all that's required to return the key fob that is not working to working condition.
key fob repairs -Remote Transponder Chips
The non-remote chips sealed in a sealed case are more durable than their remote fobs. However, they are susceptible to breaking when a hole is made in them, or in the event that a door handle of a car or lawnmowers plows over them. The failure of the fuse is usually to blame for non-remote chip failures.
If you're not comfortable opening the key fob, you may remove the circuitboard and use a multimeter to verify that the diode is operating properly. If you're not comfortable doing this, head to your local hardware store or the Oreilly's and they'll usually have a RFID frequency tester that can determine whether the key fob is sending signals.
Programming
Key fobs aren't indestructible and are susceptible to damage by a lot of things. They can lose their pairing with the receiver in your vehicle because of shocks or a low battery, requiring the reprogramming. A professional auto locksmith or a main dealer can reprogram your key fob and get it working again. If resetting or replacing your keyfob does not work it may be necessary to replace it.