How to Fix a Key Fob That isn't Working
If your key fob isn't working There are a few simple steps that can be taken to fix it. First, ensure that it's not your backup remote.
If your backup remote is unable to lock and unlock the doors of your vehicle, it is likely that the main remote isn't functioning. Most car remote key failures are caused by circuitry or battery issues.
Battery
It is not uncommon for the battery inside a car key fob to wear out. It is simple to replace batteries. However it is crucial that you use the correct kind. how to repair car key lock can consult the owner's manual or contact the manufacturer to determine the right type. It's recommended to examine the battery compartment thoroughly since dead batteries may release caustic chemicals that could harm 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 buttons seem stuck or damaged, it may be necessary to take the remote apart and rebuild its components. You could also try reprogramming your car to recognize the new key fob.
Buttons
Key fobs can get dirty and worn-out from frequent use. This is not unusual however, it can cause buttons to cease functioning or require a long press to function. This can be a hassle particularly when you're away from home and need to turn on your car. Fortunately, even worn-out or damaged buttons can be fixed with just a bit of time and some of the materials you might already have in the home.
First, make sure the batteries are up correctly and that the indentation on the back of the button is filled. Then, carefully open the remote and examine the circuit board. Check for evidence of rust, or other indications that the buttons have been damaged or worn. For example, conductive paint may be missing. Utilizing a Q-tip that has been dipped in rubbing alcohol, gently clean any membrane contacts that have become worn or have conductive paint missing. Do not rub too vigorously as this can damage the conductive paint, and block the button from firing when pressed.
Examine the battery connector's terminals carefully 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 procedure to restore functionality to any other loose connection within the fob.
In the end, if any of the rubber buttons on the front of the key fob aren't functioning or require a hard press to work it is likely that the graphite disks that are on the back of the button are wearing out and require replacement. It is usually done by rubbing a pen across the disks. This should bring the button to life.
If all of this doesn't help or if the button does not respond to a firm press, then it may be because the circuit board itself has become damaged. It is possible to fix this by a quick clean and re-soldering, but it is best to have an extra fob on hand in the event that this method does not work for you.
Circuitry
The circuit board inside your remote control may be dirty, regardless of whether the buttons on the key fob function or not. This issue can be fixed through a thorough examination. Broken and damaged cases are the most common causes of boards that are dirty. A damaged case allows water and other debris to get in and short out the electronic components. Water can also eat through pins and vias, which are the tiny connectors that are found on the board.
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 then solder new ones. It's also worth examining the battery terminal connections. If they're loose, the buttons might not function or get stuck in their down position. Soldering the terminals and buttons to their proper positions is usually enough to restore a non-working fob to working.
Non-Remote transponder chips
The non-remote chips sealed in a sealed case are more durable than remote fobs. However, they can be cracked when a hole is made in them or in the event that a door handle of a car or lawnmower runs over them. Fuse failures are usually the cause of non-remote chip failures.
If you are not comfortable opening the key fob, you may remove the circuitboard and use a multimeter to check that the diode is working correctly. If you're not sure with this, you can go to your local Oreilly or hardware store and use their RF frequency tester. This will inform you whether the key fob sends a signal.
Programming
Key fobs are subject to lots of abuse and aren't indestructible. They may lose their connection with the receiver in your vehicle because of shocks or a low-battery, which requires changing the program. A professional auto locksmith or a main dealer will be able to reprogram your key fob and get it working again. If, in the unlikely event that resetting and fixing your key fob isn't working, it could be time to replace it all over again.