How to Fix a Key Fob That isn't Working
If your key fob does not work and you're not sure why, you can fix it with just a few steps. First, check to make sure it's not the backup remote.
If the backup can lock and unlock your car door, it is most likely an issue with the primary remote. Most problems with car remote keys are caused by battery or circuitry problems.
Battery
It is not uncommon for the battery in the car key fob to degrade. It is easy to replace batteries. However it is essential to select the right kind. You can consult your owner's guide or contact the manufacturer to inquire about the right type. It is also important to inspect the battery compartment, since dead batteries can leak caustic chemicals which can damage the remote. If replacing the battery does not fix the problem, there may be other issues that require professional attention. For example, if buttons appear stuck or broken It may be necessary to disassemble the remote and rework its components. You can also try reprogramming your vehicle to recognize the new key fob.
Buttons
Key fobs may become dirty and worn out from frequent use. It is not unusual to have buttons stop working, or to require a hard push to make them work. This can be extremely frustrating, especially if you are out of town and need to start your vehicle. Fortunately, even worn-out or malfunctioning buttons can often be fixed with a little time and some of the materials you might already have in the house.
First, ensure that the batteries are charged correctly and that the indentation on the back of the button is filled. Open the remote carefully and examine the circuit board. Examine for evidence of rust, or other signs the buttons are damaged or worn out. For example there could be conductive paint missing. Then, using a Q-tip dipped in alcohol to gently clean any membrane contacts that have become damaged or where conductive paint is missing. Do not rub too vigorously in order to damage the conductive paint and prevent the button from firing when you press it.
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 in the event that this is the situation. The same procedure can be used to restore function to any loose connections within the fob.
If any of the rubber buttons on the front of the keyfob aren't working or need to be pressing extremely hard the graphite disks on the back of the button might have worn out and will require replacement. You can do this by rubbing a pencil over the disks. This should bring the button back to life.
If none of this is useful, or if the button still does not respond to a hard press It could be that the circuit board is damaged. It is possible to fix the issue by cleaning and re-soldering the button, but you should have a spare in case it doesn't work.
Circuitry
The circuit board inside your remote control may be dirty, regardless of whether the buttons on the key fob function or not. A very thorough inspection is often enough to resolve this issue. The most frequent causes of dirty circuit boards is water and damaged cases. A damaged case can allow water and other debris to get in and short circuit the electronics. Water can also damage pins and connectors on the board, referred to as via's.
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 solder new ones in their place. It's also worth looking at the battery terminal connections. key fob repair service can get very dirty and if they're loose the buttons might not function or may even remain in their down position. Soldering the terminals and button's back into place is typically all that's required to return the key fob that is not working to working condition.
Non-Remote Transponder Chips
The non-remote chips sealed in a sealed case are more durable than remote fobs, but they can be cracked when a hole is made into them or in the event that a door handle of a car or lawnmowers plows over them. Most of the time, non-remote transponder chips fail, and this can be blamed on an exploded fuse.
If you are not comfortable opening the key fob, you may remove the circuitboard and use a multimeter to verify that the diode is working properly. If you're unsure about doing this, visit your local hardware store or the Oreilly's and they will usually have an radio frequency tester that can determine if the key fob is transmitting a signal.
Programming
Key fobs are not indestructible and are susceptible to being damaged through a variety of causes. They can break their connection with the receiver in your vehicle because of shocks or a low battery, which calls for reprogramming. A professional auto locksmith or a main dealer can reprogram your key fob to get it back up and running. If, in the unlikely event that resetting and repairing your key fob fails it may be time to replace it completely.