How to Fix a Key Fob That isn't Working
If your key fob does not work, you can fix it by following a few simple steps. First, check to make sure it's not your backup remote.
If the backup remote is able to lock and unlock your car doors, then there's a likely issue with the primary remote. The most frequent causes of key problems with your car remote are circuitry or battery issues.
Battery
It is not uncommon for the battery inside the key fob for cars to degrade. It is easy to replace batteries. However it is crucial that you choose the right type. car key repair service can refer to your owner's guide or contact the manufacturer to inquire about the right type. It's also a good idea to inspect the battery compartment thoroughly, as dead batteries sometimes release caustic chemicals that could damage the remote. If changing the batteries does not solve the issue it could be because there are other issues that require attention by a professional. If buttons are broken 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
Due to repeated use, key fobs can wear out and become dirty. This is not unusual however, it can cause buttons to stop working or require a difficult press to get them to work. This can be very frustrating, especially if you are away from home and you need to start your vehicle. Fortunately, even worn-out or malfunctioning buttons can often be fixed with a little time and a few materials you might already have in the house.
First, ensure that the batteries are charged correctly and that the indentation on the back of the button is filled. Then, carefully open up the remote and examine the circuit board. Look for evidence of rust, or other signs the buttons are damaged or worn. For instance there could be conductive paint missing. Utilizing the Q-tip, dipped in alcohol to gently clean any membrane contacts that are damaged or have conductive paint missing. Avoid rubbing too hard since this could cause damage to the conductive painting and prevent the button from firing when it is pressed.
Check the battery connector terminals for loose solder connections. Soldering them back to their original position can restore the button's functionality in the event that this is the situation. You can follow the same procedure to restore functionality to any other loose connection inside the fob.
If any of the rubber buttons on the front of the keyfob are not working or need to be pressed very hard, the graphite disks at the back of the button may have worn out and will need to replaced. This can be done by rubbing a pencil over the disks. This should bring the button back to life.
If none of this is helpful, or if the button still doesn't respond to a hard press, then it may be that the circuit board itself has become damaged. It is possible to fix the issue by cleaning and re-soldering your fob however, you should have a spare in case it doesn't work.
Circuitry
The circuit board of the remote control could be dirty, regardless of whether the buttons on the key fob are working or not. A thorough inspection will usually resolve this problem. The most frequent causes of dirty circuit boards are water and damaged cases. A damaged case could allow water and other debris to get into the circuit board, which can cause it to short. Water can also get through pins and vias, which are the tiny connectors that are found on the board.
If you are handy enough to open your key fob and aren't afraid of making some mess, we can remove the buttons from their sockets and then solder new ones. It's also worth looking at the battery terminal connections. 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 button's back into place is typically all it takes to restore a non-working key fob to functioning condition.
Non-Remote Transponder Chips
Sealed non-remote transponder chip are more durable than the remote fobs that contain them but they can still be damaged by a hole that is made in them or pushed over by a lawnmowers blade or door handle for a car. Most of the time, non-remote transponder chip failures can be blamed on an exploded fuse.
If you're not comfortable opening the key fob, remove the circuitboard and use a multimeter to check that the diode is operating properly. If you're not confident doing this, head to your local hardware store or Oreilly's and they'll usually have an radio frequency tester that can tell you if the key fob is sending signals.
Programming
Key fobs aren't indestructible and can be damaged by a lot of things. They can lose their pairing to the receiver in your car because of shock or a low battery, requiring them to be reprogrammed. A professional auto locksmith, or the main dealer, can reprogram your keyfob and get it functioning again. If resetting or repairing your key fob fails it may be necessary to replace it.