How to Fix a Key Fob That isn't Working
If your key fob isn't functioning A few easy steps can fix it. The first step is to be sure it's not the backup remote.
If the backup remote is able to lock and unlock your car doors then there is likely an issue with the primary remote. The most frequent causes of key problems with your car remote are circuitry or battery issues.
Battery
The battery inside the key fob could wear out over time. It is easy to replace the battery. However it is essential that you choose the right kind. You can check your owner's manual or call the manufacturer to inquire about the correct type. It's also a good idea to examine the battery compartment carefully because dead batteries can leak caustic chemicals that can cause damage to the remote. If replacing the battery does not fix the problem there could be other issues that require attention from a professional. If the buttons are broken or stuck, for example it could be necessary to remove the remote and rebuild each component. You can also try reprogramming the vehicle to recognize the new remote.
Buttons
From repeated use, key fobs may become worn and dirty. It is not common for buttons to cease functioning, or require a hefty press to make them work. This can be very frustrating particularly if you're away from home and need to start your car. Even broken or damaged buttons can be fixed with a bit of time and materials you already have at home.
First, verify that the batteries have been correctly installed and that the indentation at the back of the button has been filled. Then, carefully open up the remote and inspect the circuit board. Examine for signs of rust or other signs that the buttons are worn or damaged, such as missing the conductive paint. Use the Q-tip, dipped in rubbing alcohol, gently clean any membrane contacts that have become worn or where conductive paint is missing. Be careful not to rub too hard, since this could cause damage to the conductive paint and stop the button firing when it is pressed.
Also, be sure to check the battery connector's terminals for a loose solder connection. Soldering them back into place can restore the button's functionality in the event that this is the situation. The same method can be used to restore functionality to any other loose connections 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 deteriorating and require replacement. This can usually be done by rubbing a pencil on the disks, which will bring the button back to working.
If all of this doesn't help or if the button does not respond to a hard press, then it may be because the circuit board itself is damaged. It is possible to fix this by a quick clean, and replacing the solder, but it is ideal to have a spare fob on hand in the event that this method fails for you.
Circuitry
The circuit board in your remote control could be dirty, regardless of whether the buttons on the key fob work or not. This problem can be resolved by a thorough inspection. The most common causes of dirty circuit boards are water and broken cases. A damaged case could allow water and other debris to get into the circuit board, which can cause it to short. car key repairs can also damage pins and connectors that are small on the board, which are known as via's.
If you're able to open your key fob, and you don't mind making a mess, we can take the buttons out of their sockets and then solder new ones. Also, you should check the connections between the battery terminals. If they are loose, the buttons could not function properly or become stuck in their down position. Soldering the terminals and button's back in place is usually all that's required to return keys that are not in working condition.
Non-Remote Transponder Chips
Sealed non-remote transponder chips are more durable than remote fobs that contain them however they are still susceptible to being damaged by a hole that is made in them or pushed over by a lawnmowers or car door handle. Most of the time, non-remote transponder chips fail, and this could be attributed to a blown fuse.
If you are not comfortable opening the key fob, you can remove the circuitboard and use a multimeter to determine if the diode is operating properly. If you don't feel comfortable with this, you can go to your local Oreilly or hardware store and use their RF frequency tester. This will tell you whether the key fob sends a signal.
Programming
Key fobs take lots of abuse and aren't indestructible. They may lose their connection to the car's receiver due to shock or low battery, requiring the reprogramming. A professional auto locksmith or a dealer in the main can reprogram your keyfob and get it working again. In the event that resetting or repairing your key fob fails it may be time to replace it completely.