How to Fix a Key Fob That isn't Working

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

If your backup remote can unlock and lock the doors of your car, it is likely that the primary remote is not working. The most frequent causes of key malfunctions for car remotes are battery or circuitry issues.

Battery

The battery inside the key fob could wear out over time. It is quite simple to change out a battery, although it is important to ensure you choose the correct type and you can consult your owner's manual, or contact the dealer of the manufacturer to determine the type of battery you need. It is also crucial to inspect the battery compartment, since batteries that are not working properly can release caustic chemicals which can damage the remote. If changing the batteries doesn't solve the problem it could be that there are other issues that require attention from a professional. For instance, if the buttons seem to be stuck or damaged it could be necessary to take the remote apart and rework its components. You can also try reprogramming your vehicle to recognize the new key fob.

Buttons

Key fobs can become dirty and worn-out from repeated use. This is not uncommon, but it can cause buttons to stop working or require a very long press to function. This can be very frustrating especially if you're out of town and need to start your vehicle. Fortunately, even worn out or malfunctioning buttons can often be fixed with just a bit of time and a few items you have in the house.

First, verify that the batteries are properly placed and that the indentation at the back of the button is filled. Then, carefully open the remote and fobs examine the circuit board. Look for evidence of rust, or other signs the buttons are damaged or worn out. For instance the paint that conducts electricity could be missing. Use a Q-tip, dipped in alcohol to gently clean any membrane contact that is worn-out or where conductive painting is missing. Don't rub too hard, as this could erode the conductive paint, and block the button from firing when you press it.

Also, be sure to check the battery connector's terminals for a loose solder connection. If this is the case, simply soldering them back in place can restore function to the button. You can apply the same process to restore functionality to any other loose connection inside the fob.

Finally, if any of the buttons made of rubber on the front of the key fob have stopped working or require a very long press to function, it is likely that the graphite disks on the back of the button are wearing out and require replacement. This can be done by rubbing a pencil across the disks. This should bring the button back to working.

If none of this is helpful, or if the button still doesn't respond to a hard push It could be that the circuit board has gone bad. This can sometimes be repaired by a quick clean, and re-soldering, but it is ideal to have a spare fob on hand in the event that this method does not work for you.

Circuitry

The circuit board inside your remote control could be dirty, regardless of whether the buttons on the key fob are working or not. This issue can be fixed through a thorough examination. Broken cases and water are the most frequent causes of dirty boards. A broken case allows water and other debris to pass through and short out the electronic components. Water can also eat away at pins and connectors that are small on the board, referred to as via's.

If you're handy enough to open your key fob and aren't afraid of a little mess, we can take off the buttons and solder new ones in their place. Also, you should check the connections between battery terminals. They can become extremely dirty and if they're loose the buttons might not work or may even remain in their down position. Soldering the terminals, and putting the button back into place is typically all that's required to return the key fob that is not working to working order.

Non-Remote transponder chips

Sealed non-remote transponder chips are much more durable than remote fobs that contain them however they are still susceptible to being damaged by a hole that is that is drilled into them or over by a lawnmower or car keys repair door handle. The failure of the fuse is usually to blame for non-remote chips failures.

If you're not comfortable opening the key fob, you may remove the circuitboard and use a multimeter to determine if the diode is operating correctly. If you don't feel comfortable with this, go to your local Oreilly or hardware store and test their RF frequency tester. This will let you know whether the key fob transmits a signal.

Programming

Key fobs aren't impervious to destruction and fobs are susceptible to being damaged by a variety of factors. They may lose their connection to the receiver in your car because of shock or a low battery, which calls for them to be reprogrammed. A professional auto locksmith, or main dealer can reprogram the key fob and get it back up and running again. If, in the unlikely event that resetting and repairing your key fob fails, it could be time to replace it completely.