How to Fix a Key Fob That isn't Working
If your key fob isn't working There are a few simple steps that can fix it. First, check to make sure it's not your backup remote.
If your backup remote is unable to unlock and lock the doors of your car, it is likely that the main remote is not working. The most common causes of key problems with your car remote are circuitry or battery issues.
Battery
It is not unusual for the battery inside a key fob for cars to wear out. It is easy to replace a battery. However, it is important to select the right kind. You can consult the owner's manual or contact the manufacturer to determine the right kind. It's recommended to examine the battery compartment thoroughly, as dead batteries sometimes release caustic chemicals that could damage the remote. If changing the battery doesn't solve the issue there may be additional issues that require attention from a professional. For instance, if buttons seem to be stuck or damaged, it may be necessary to disassemble the remote and rework its components. You could also try reprogramming your vehicle to recognize the new key fob.
Buttons
From frequent use, key fobs could become worn and dirty. It is not unusual to have buttons stop functioning, or require a hard press to get them working. This can be a hassle particularly when you're away from your home and have to turn on your car. Even malfunctioning or worn-out buttons can be fixed with a bit of time and the tools you already have at home.
First, make sure that the batteries are correctly installed and that the indentation on the back of the button has been filled. Then, carefully open the remote and inspect the circuit board. Examine for indications of rust or other indications that the buttons are damaged or worn. For instance, conductive paint may be missing. Use a Q-tip that has been dipped in rubbing alcohol, gently clean any membrane contacts that have worn or have conductive paint missing. Be careful not to rub too hard, as this can erode the conductive paint and block the button from firing when pressed.
Also, make sure to inspect the battery connector terminals for an unattached solder connection. Soldering them back in place can restore the button's functionality in the event that this is the case. You can use the same process to restore functionality to any other loose connection within the fob.
If, for instance, any of the rubber buttons on the front of the key fob aren't functioning or require a long press to function it is likely that the graphite disks that are on the back of the button are wearing down and require replacement. It is usually done by rubbing a pen over the disks. This should bring the button to life.
If none of these solutions work, or if you still are unable to get the button to respond when you press it hard, it could be that the circuitry is failing. It is possible to fix this issue by cleaning and re-soldering your fob, but you should have another spare in case it doesn't work.
Circuitry
The circuit board in the remote control could be dirty, regardless of whether the buttons on the key fob work or not. A thorough inspection will usually resolve this issue. Broken and damaged cases are the most common causes of boards that are dirty. A broken case can let water and other debris to enter the circuit board, which can cause it to short. Water can also damage pins and connectors on the board, which are known as via's.
If you're handy enough to open up your key fob, and you're not afraid of some mess, we can de-solder the buttons and solder new ones in their place. It's also worth looking at the battery terminal connections. If they're loose, the buttons might not function or get stuck in their down position. Soldering the terminals back to their original positions is often enough to restore a non-working fob back to working.
nearby key repair shop -Remote Transponder Chips
Sealed non-remote transponder chips are more durable than the remote fobs that have them but they can be damaged by a hole that is made in them or pushed over by a lawnmowers or car door handle. The failure of the fuse is usually to blame for non-remote chip failures.
If you're able to open a sealed non-remote key fob and are able to bear the mess, you can remove the circuit board and check the fuse using an instrument to verify diode function. If you're unsure about doing this, go to your local hardware store or the Oreilly's and they will usually have an radio frequency tester that can tell you if the key fob is sending signals.
Programming
Key fobs are subject to lots of abuse and aren't impervious to damage. They may lose their connection with the receiver in your vehicle due to shocks or a low battery, which calls for the reprogramming. A professional auto locksmith or the main dealer can reprogram your keyfob and get it functioning again. If, in the unlikely event that resetting and repairing your key fob doesn't work, it could be time to replace it all over again.