How to Fix a Key Fob That isn't Working
If your key fob won't work then you can fix it by following a few simple steps. First, make sure that it's not the backup remote.
If your backup remote cannot unlock and lock the doors of your vehicle, it is most likely that the primary remote isn't functioning. The most common causes for key malfunctions for car remotes are issues with the circuitry or battery.
Battery
The battery in the key fob could get worn out over the course of time. It is quite simple to replace the battery, however it is important to make sure that you select the correct one and you can consult your owner's manual, or contact the manufacturer's dealer to find out the kind of battery you require. It is recommended to examine the battery compartment thoroughly since dead batteries may release caustic chemicals that could damage the remote. If changing the battery doesn't solve the issue there may be additional issues that require attention from a professional. For instance, if buttons seem to be stuck or broken, it may be necessary to disassemble the remote and rework its parts. 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 atypical, but it can cause buttons to cease functioning or require a long press to work. This can be a hassle especially when you're away from home and need to start your car. Fortunately, even worn out or damaged buttons can be fixed with a bit of time and a few items you have in the home.
First, verify that the batteries are properly installed and that the indentation at the back of the button has been filled. Then, carefully open the remote and inspect the circuit board. Examine for signs of rust or other indications that the buttons are worn or damaged, such as missing the conductive paint. Then, using a Q-tip that has been dipped in alcohol to gently clean any membrane contacts that have become worn or have conductive paint missing. Don't rub too hard, as this could erode the conductive paint and prevent the button from firing when it is pressed.
Also, make sure to inspect the battery connector terminals for any loose solder connections. If this is the case, simply soldering them back in place could bring back function to the button. You can use the same process to restore functionality to any other loose connection within the fob.
In the end, if any of the buttons made of rubber that are on the front of the key fob stop working or require a very difficult press to function it is likely that the graphite disks that are on the back of the button are wearing out and require replacement. This can usually be done by rubbing a pencil over the disks, which will bring the button back to working.
If none of this is helpful, or if the button doesn't respond to a hard push, then it may be the case that the circuit board has gone bad. It is possible to fix this issue by cleaning and re-soldering the button, but you should have an extra in case it does not work.
Circuitry
Whether or not the key fob buttons function, the circuit board inside your remote may be dirty. A thorough inspection is usually enough to fix this issue. The most frequent causes of dirty circuit boards are water and broken cases. broken car key repair near me damaged case can allow water and other debris to enter the circuit board, which can cause it to short. Water can also destroy pins and connectors that are small on the board called via's.
If you are handy enough to open your key fob and don't mind making an mess, you can take the buttons out of their sockets and put in new ones. Also, you should check the connections between the battery terminals. They can become extremely dirty and if they're loose the buttons might not function or may even remain in their down position. Soldering the terminals back into place is usually enough to return a malfunctioning fob to a working condition.
Non-Remote Transponder Chips
The non-remote chips sealed in a sealed case are more durable than remote fobs, however they can be cracked in the event of a hole being drilled in them or if a car door handle or lawnmowers plows over them. Most of the time, non-remote transponder chip malfunctions could be attributed to an exploded fuse.
If you're handy enough to open up the sealed key fob and can tolerate the mess, you can remove the circuit board and test the fuse with a multimeter for proper diode function. If you're not comfortable doing this, head to your local hardware store or Oreilly's and they usually have a RFID frequency tester that can determine whether the key fob sending signals.
Programming
Key fobs aren't impervious to destruction and are susceptible to being damaged through a variety of causes. They may lose their connection with the receiver inside your vehicle because of shocks or a low-battery, which requires changing the program. A professional auto locksmith or main dealer, can reprogram your keyfob and get it functioning again. If resetting or fixing your key fob fails it may be necessary to replace it.