How to Fix a Key Fob That isn't Working
If your key fob isn't working, a few easy steps can fix it. First, make sure that it's not your backup remote.
If the backup remote is able to lock and unlock your car doors, it is most likely an issue with the primary remote. Most problems with car remote keys are caused by circuitry or battery issues.
Battery
The battery inside the key fob may be worn out over time. It is fairly easy to change out batteries, but it is crucial to make sure that you use the right type and you can consult your owner's manual, or contact the dealer of the manufacturer to determine the type of battery you require. It is also essential to check the battery compartment, since dead batteries can leak caustic chemicals that can harm the remote. If changing key car repair doesn't fix the issue there could be other issues requiring professional attention. If the buttons are stuck or broken, for example it might be necessary to take the remote apart and rework each component. You can also try reprogramming your car to recognize the new key fob.
Buttons
Through repeated use, key fobs may get dirty and worn. It is not uncommon to have buttons stop working, or to require a long push to make them work. This can be very frustrating particularly if you're away from home and need to start your car. Even worn-out or malfunctioning buttons can be fixed with a bit of time and tools you already have at home.
First, ensure that the batteries are properly charged 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 rust or other signs the buttons have been damaged or worn out. For example, conductive paint may be missing. Use a Q-tip that has been 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, since this could cause damage to the conductive painting and prevent the button firing when it is pressed.
Also, be sure to check the battery connector's terminals to ensure an unattached solder connection. Soldering them back in place will restore the button's functionality If this is the case. The same method can be used to restore function to any other loose connections inside the fob.
If, for instance, any of the buttons made of rubber that are on the front of the key fob have stopped working or require a very hard press to work it is likely that the graphite disks on the back of the button are wearing out and need to be replaced. This is usually done by rubbing a pencil on the disks, which should bring the button back to life.
If none of these solutions work or you are unable to get the button to respond when you press it hard, it could be that the circuitry has failed. This can be fixed by a quick clean, and re-soldering, but it is recommended to have an additional fob in case this method does not work for you.
Circuitry
If the key fob buttons function, the circuit board inside the remote could be dirty. A very thorough inspection is often enough to resolve this problem. The most common causes of dirty circuit boards are water and broken cases. A broken case can let water and other debris to get into the circuit board, which can cause it to short out. Water can also damage pins and vias, which are the tiny connectors found on the board.
If you're able to remove your key fob and don't mind making a mess, we can remove the solder from the buttons and then solder new ones in their place. It's also worth checking the battery terminal connections. If they are loose, the buttons might not function properly or become stuck in their down position. Soldering the terminals and buttons to their original positions is often enough to restore a non-working fob back to working.
Non-Remote Transponder Chips
The sealed non-remote chips are more durable than their remote fobs, however they can be cracked if a hole is drilled in them, or if a car door handle or lawnmowers is pushed over them. Most of the time, non-remote transponder chips fail, and this could be attributed to blowing fuses.
If you're able to open up the sealed key fob and are able to bear the mess, you can take off the circuit board and check the fuse using a multimeter for proper diode function. If you're not sure with this, visit your local Oreilly or hardware store and test their RF frequency tester. This will let you know whether the key fob is sending signals.
Programming
Key fobs are subject to many abuses and aren't indestructible. They can break their connection with the receiver inside your vehicle due to shocks or a low battery, requiring reprogramming. A professional auto locksmith or main dealer can reprogram your key fob to get it working again. In the rarer case that resetting or repairing your key fob fails it may be time to replace it entirely.