How to Fix a Key Fob That isn't Working

If your key fob won't work, you can fix it with just a few steps. The first step is to be sure that it's not the backup remote.

If your backup remote is unable to unlock and lock the doors of your car, then it is most likely that the primary remote isn't functioning. Most car remote key failures are caused by circuitry or battery problems.

Battery

The battery inside a key fob can wear out over time. It is easy to replace a battery. However, it is important to select the right type. You can check your owner's guide or contact the manufacturer to determine the right kind. It is also crucial to check the battery compartment, as batteries that are not working properly can release toxic chemicals that could damage the remote. If changing the batteries doesn't solve the problem it could be because there are other issues that require professional attention. If the buttons are damaged or stuck for instance it could be necessary to disassemble the remote and rework each component. You can also try reprogramming the vehicle to recognize the new remote.

Buttons

Key fobs can get dirty and worn out from repeated use. It is not unusual for buttons to stop functioning, or require a hefty push to make them work. This can be a huge hassle especially if you're out of town and need to start your vehicle. Even broken or damaged buttons are often fixable with a little effort and tools you already have at home.

First, verify that the batteries are properly placed and that the indentation at the back of the button is filled. Take the remote apart and look over the circuit board. Check for signs of rust or other signs the buttons are damaged or worn out. For example there could be conductive paint missing. Use a Q-tip, dipped in alcohol to gently clean any membrane contact that has become worn out or has conductive paint missing. Do not rub too vigorously, as this could erode the conductive paint and prevent the button from firing when it is pressed.

Check the battery connector terminals carefully for any loose solder connections. If this is the case, simply connecting them back could restore functionality to the button. The same process can be used to restore function to any other loose connections within the fob.

Finally, if any of the buttons made of rubber on the front of the key fob stop working or require a very long press to function, it is likely that the graphite disks that are on the back of the button are deteriorating and need to be replaced. This is usually done by rubbing a pencil over the disks. This should bring the button back to working.

If all of this doesn't help or if the button still does not respond to a hard press It could be the case that the circuit board itself has become damaged. read more is possible to fix this by a quick clean and re-soldering, but it is recommended to have an additional fob available in the event this method doesn't work for you.

Circuitry

Whether or not the key fob buttons are working, the circuit board inside your remote might be dirty. The issue can be solved through a thorough examination. Broken cases and water are the most frequent causes of dirty boards. A damaged case can allow water and other debris to get in and short out the electronics. Water can also eat through pins and vias, which are the tiny connectors on the board.

If you're able to open your key fob and you don't mind making an mess, you can remove the buttons from their sockets and put in new ones. Also, it's worth checking the connections between battery terminals. If they're loose, the buttons could not work or even become stuck in their down position. Soldering the terminals back into place is usually enough to bring a non-working fob back to working.

Non-Remote transponder chips

The non-remote chips sealed in a sealed case are more durable than their remote fobs, however they are susceptible to cracking if a hole is drilled in them or when a door handle for a car or lawnmowers is pushed over them. Fuse failures are usually to blame for non-remote chip failures.

If you're able to open up a key fob that is sealed and are able to bear the mess, you can remove the circuit board and examine the fuse using an instrument to verify diode function. If you're not comfortable with this, you can go to your local Oreilly or hardware store and use their RF frequency tester. This will let you know whether the key fob is sending signals.

Programming

Key fobs endure a lot of abuse and aren't impervious to damage. They may lose their connection to the receiver in your car due to shock or low battery, which calls for them to be reprogrammed. A professional auto locksmith or a main dealer can reprogram your key fob to get it functioning again. If resetting or fixing the keyfob is not working it is possible to replace it.
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