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 by following just a few steps. The first step is to be sure that it's not the backup remote.
If your backup remote is unable to lock and unlock the doors of your car, it is likely that the primary remote isn't functioning. The most frequent causes of key problems with your car remote are battery or circuitry issues.
Battery
It is not unusual for the battery inside a key fob for cars to degrade. It is easy to replace batteries. However it is essential that you use the correct type. You can refer to your owner's guide or contact the manufacturer to find out the correct type. It's also a good idea to examine the battery compartment thoroughly since dead batteries may leak caustic chemicals that can cause damage to the remote. If changing the batteries doesn't solve the problem, it may be that there are other issues that require professional attention. If the buttons are stuck or broken for instance it might be necessary to disassemble the remote and rework each component. You can also try reprogramming the vehicle to recognize the new device.
Buttons
Key fobs may become dirty and worn out from repeated use. This is not uncommon, but it can cause buttons to cease working or require a difficult press to get them to work. This can be a huge hassle, especially if you are away from home and you need to start your vehicle. Fortunately, even worn-out or damaged buttons can be fixed with a bit of time and a few materials you might already have in the house.
First, check that the batteries are properly installed and that the indentation on the back of the button is filled. Then, carefully open the remote and examine the circuit board. Check for signs of corrosion or other signs that buttons are worn out or damaged, like missing conductive paint. Then, using a Q-tip that has been dipped in rubbing alcohol, gently clean any membrane contacts that have become damaged or where conductive paint is missing. Don't rub too hard in order to damage the conductive paint, and block the button from firing when you press it.
Also, carefully check the battery connector's terminals for an unattached solder connection. Soldering them back to their original position will allow the button to function again in the event that this is the situation. linked internet page can follow the same procedure 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 that the graphite disks that are on the back of the button are wearing down and require replacement. 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 this is useful or if the button still doesn't respond to a firm press It could be the case that the circuit board itself has become damaged. It is possible to fix this by cleaning and re-soldering the fob but you should also have another spare in case it does not work.
Circuitry
The circuit board of your remote control may be dirty, regardless of whether the buttons on the key fob are working or not. A thorough inspection will usually resolve this issue. The most frequent causes of dirty circuit boards are water and damaged cases. A damaged case can let water and other debris into the circuit board, causing it to short out. Water can also eat through pins and vias, which are small connectors found on the board.
If you're handy enough to open your key fob, and you're not afraid of making a mess, we can remove the solder from the buttons and solder new ones in their place. Also, you should check the connections between battery terminals. They can become extremely dirty and if they're loose, the buttons might not function or even stay in their down position. Soldering the terminals and buttons back into place is typically all that's needed to return the key fob that is not working to functioning condition.
Non-Remote Transponder Chips
The non-remote chips sealed in a sealed case are more durable than their remote fobs, but they are susceptible to cracking if a hole is drilled in them, or if a car door handle or lawnmowers is pushed over them. Fuse failures are usually to blame for non-remote chip failures.
If you are not comfortable opening the key fob, take the circuit board off and use a multimeter to check that the diode is working correctly. If you're not sure with this, you can visit your local Oreilly or hardware store and test their RF frequency tester. This will inform you whether the key fob transmits an RF signal.
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 low battery, which requires them to be reprogrammed. A professional auto locksmith or main dealer will be able to reprogram your key fob to get it back up and running. If resetting or repairing your keyfob does not work it may be necessary to replace it.