How to Fix a Key Fob That isn't Working
If your key fob won't work, you can fix it by following just a few steps. The first step is to be sure it's not the backup remote.
If the backup can lock and unlock your car doors it is most likely an issue with the primary remote. Most problems with car remote keys result from circuitry or battery issues.
repair car key fob in the key fob may get worn out over the course of time. It is relatively easy to change out the battery, however it is essential to ensure you use the right type; you can look in your owner's manual, or contact the dealer for the manufacturer to find out the kind of battery you need. It is also important to examine the battery compartment, since batteries that are not working properly can release caustic chemicals which can damage the remote. If changing the battery doesn't fix the issue there may be additional issues that require attention from a professional. If the buttons are stuck or broken for instance, it may be necessary take the remote apart and rework each component. You could also try reprogramming the vehicle to recognize the new key fob.
Buttons
Due to frequent use, key fobs may become worn and dirty. This is not atypical however it can cause buttons to stop working or require a very long press to work. This can be a hassle, especially when you are away from home and you need to switch on your car. Even worn-out or malfunctioning buttons can be fixed with a bit of time and materials you already have at home.
First, verify that the batteries are correctly installed and that the indentation on the back of the button has been filled. Take the remote apart and look over the circuit board. Check for signs of corrosion or other signs that the buttons are worn out or damaged, such as missing paint that is conductive. 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. Don't rub too hard in order to damage the conductive paint and stop the button from firing when it is pressed.
Also, make sure to inspect 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 use the same process 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 aren't working or require a hard press to work it is likely the graphite disks on the back of the button are wearing down and need to be replaced. This is usually done by rubbing a pencil over the disks. This should bring the button back to life.
If all of this doesn't help or if the button does not respond to a firm press It could be because the circuit board itself has gone bad. It is possible to fix the issue by cleaning and re-soldering your fob, but you should have another spare in case it does not work.
Circuitry
Whether or not the keys fob buttons are functioning the circuit board in your remote might be dirty. The issue can be solved by a thorough inspection. Broken cases and water are the most frequent causes of boards that are dirty. A damaged case could allow water and other debris to enter the circuit board, causing it to short out. Water can also damage pins and vias, which are tiny connectors that are found on the board.
If you are handy enough to open your key fob and you don't mind making a mess, we can remove the buttons from their sockets and then solder new ones. Also, you should check the connections between battery terminals. If they are loose, the buttons could not work or even become stuck in their down position. Soldering the terminals and button's back in their place is generally all that's needed to return the key fob that is not working to working condition.
Non-Remote transponder chips
Sealed non-remote transponder chip are more durable than remote fobs that contain them but they can still be damaged by a hole that is that is drilled into them or over by a lawnmowers blade or car door handle. Fuse failures are usually the cause of non-remote chip failures.
If you're able to remove a sealed non-remote key fob and are able to bear the mess, you can remove the circuit board and examine the fuse with an instrument to verify diode function. If you're not confident doing this, go to your local hardware store or Oreilly's, and they will usually have an RFID frequency tester that can let you know whether the key fob is transmitting a signal.
Programming
Key fobs aren't impervious to destruction and are susceptible to damage through a variety of causes. They may lose their connection to the car's receiver due to shock or low battery, which requires the reprogramming. A professional auto locksmith, or the main dealer can reprogram the keyfob to get it functioning again. If resetting or replacing your key fob fails, you may need to replace it.