How to Fix a Key Fob That isn't Working
If your key fob doesn't work, you can fix it by following some simple steps. First, make sure that it's not your backup remote.
If your backup remote is unable to unlock and lock the doors of your vehicle, it is likely that the main remote is not working. Most car remote key failures result from circuitry or battery issues.
Battery
It is not unusual for the battery in a car key fob to degrade. It is easy to replace the battery. However it is essential to select the right type. You can check the owner's manual or contact the manufacturer to inquire about the right kind. car key repair service is also a good idea to examine the battery compartment carefully since dead batteries may leak caustic chemicals that can damage the remote. If changing the batteries doesn't solve the problem it could be because there are other issues that require attention by a professional. If buttons are broken or stuck, for example it might be necessary to disassemble the remote and rework each component. You can also try reprogramming your vehicle to recognize the new key fob.
Buttons
Key fobs can become dirty and worn out from frequent use. It is not uncommon for buttons to stop functioning, or require a hard push to make them work. This can be a huge hassle especially if you're away from home and you need to start your vehicle. Fortunately, even worn out or broken buttons can usually be fixed with just a bit of time and some of the materials you might already have in the home.
First, ensure that the batteries are charged correctly and that the indentation on the back of the button is filled. Take the remote apart and look over the circuit board. Check for indications of rust or other signs the buttons are worn or damaged. For instance, conductive paint may be missing. Use a Q-tip, dipped in rubbing alcohol to gently clean any membrane contact that has become worn-out or where conductive painting is missing. Avoid rubbing too hard, because this could damage the conductive paint and stop the button firing when the button is pressed.
Check the battery connector's terminals for loose solder connections. Soldering them back to their original position will allow the button to function again If this is the case. The same process can be used to restore function to any loose connections within the fob.
In the end, if any of the rubber buttons on the front of the key fob stop working or require a hard press to work, it is likely that the graphite disks on the back of the button are wearing down and require replacement. You can usually do this by rubbing a pencil over the disks. This should bring the button back to life.
If none of these solutions work, or if you still are unable to get the button to respond when pressed hard, it is possible that the circuitry is failing. It is possible to fix this by cleaning and re-soldering your fob, but you should have a spare in case it does not work.
Circuitry
If the key fob buttons are working the circuit board that is inside the remote could be dirty. A thorough inspection is usually enough to fix this issue. The most common causes for 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 damage pins and connectors that are small on the board, which are known as via's.
If you're able to open up your key fob and aren't afraid of some mess, we can take off the buttons and put new ones in their place. It's also worth looking at the battery terminal connections. They can become extremely dirty and if they're loose, the buttons might not function or even stick in their down position. Soldering the terminals and button's 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
Sealed non-remote transponder chip are more durable than the remote fobs they are contained in, but they can be damaged by a hole that is made in them or pushed over by a lawnmower or car door handle. Most of the time, non-remote transponder chip malfunctions can be attributed to an exploded fuse.
If you're not confident opening the key fob, you may take the circuit board off and use a multimeter to verify that the diode is functioning properly. If you're unsure about doing this, visit your local hardware store or Oreilly's and they'll usually have an RFID frequency tester that can let you know if the key fob is sending signals.
Programming
Key fobs endure a lot of abuse and aren't indestructible. They can lose their pairing to the car's receiver due to shock or low battery, which calls for them to be reprogrammed. A professional auto locksmith or a main dealer will be able to reprogram your key fob and get it functioning again. In the rarer case that resetting or repairing your key fob fails it may be time to replace it all over again.
