How to Fix a Key Fob That isn't Working
If your key fob won't work then you can fix it with a few simple steps. First, ensure that it's not your backup remote.
If your backup remote is unable to unlock and lock the doors of your car, then it is likely that the main remote isn't functioning. The most common causes for car remote key failure are issues with the circuitry or battery.
Battery
The battery inside the key fob could be worn out over time. It is simple to replace the battery. However, key fob repair is important that you choose the right type. You can consult your owner's guide or contact the manufacturer to find out the right type. It is also essential to examine the battery compartment as batteries that are not working properly can release caustic chemicals that can harm the remote. If replacing the batteries doesn't solve the issue it could be that there are other issues that require attention by a professional. If buttons are broken or stuck, for example, it may be necessary take the remote apart and rework each component. You can also try reprogramming the vehicle to recognize the new remote.
Buttons
Key fobs can get filthy and worn out due to frequent use. This is not atypical however, it can cause buttons to stop functioning or require a hard press for them to work. This can be very frustrating especially if you're away from home and you need to start your car. Fortunately, even worn-out or malfunctioning buttons can often be fixed with just a bit of time and a few materials you may already have around the home.
First, verify that the batteries are properly placed and that the indentation at the back of the button is filled. Then, carefully remove the remote and examine the circuit board. Look for signs of corrosion or other signs that the buttons are worn or damaged, like missing paint that is conductive. Use a Q-tip dipped into alcohol to gently clean any membrane contact that is worn out or where conductive paint is missing. Be careful not to rub too hard, since this could cause damage to the conductive paint and block the button from firing when the button is pressed.
Also, carefully check the battery connector terminals for a loose solder connection. Soldering them back in place can restore the button's functionality if this is the situation. You can use the same method to restore functionality to any other loose connection inside the fob.
If any of the rubber buttons at the front of the keyfob isn't functioning or require to be press extremely hard the graphite disks on the back of the button could have worn out and require replacement. It is usually done by rubbing a pencil over the disks. This should bring the button to life.
If none of these solutions work or you cannot 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
The circuit board inside the 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. The most common causes for dirty circuit boards are water and broken cases. A damaged case allows water and other debris to pass through and short circuit the electronics. Water can also destroy pins and connectors that are small on the board, referred to as via's.
If you're skilled enough to open your key fob, and aren't afraid of making an mess, you can remove the buttons from their sockets and solder in new ones. Also, it's worth checking the connections between the battery terminals. If they're loose, the buttons may not work or even become stuck in their down position. Soldering the terminals and button's back in their place is generally all that's needed to return keys that are not in working condition.
Non-Remote Transponder Chips
The sealed non-remote chips are more durable than remote fobs, however they can be cracked when a hole is made into them or in the event that a door handle of a car or lawnmower runs over them. Most of the time non-remote transponder chip failures can be blamed on blowing fuses.
If you're not comfortable opening the key fob, you can remove the circuitboard and use a multimeter to verify that the diode is working properly. If you're not comfortable with this, you can go to your local Oreilly or hardware store and test their RF frequency tester. This will tell you whether the key fob sends an RF signal.
Programming
Key fobs aren't indestructible and can be damaged by a variety of factors. They can lose their pairing to the car's receiver due to shock or low battery, which calls for them to be reprogrammed. A professional auto locksmith or main dealer will be able to reprogram your key fob and get it working again. In the event that resetting or repairing your key fob isn't working, it could be time to replace it completely.