Don't Buy Into These "Trends" Concerning Remote Key Repair
How to Fix a Key Fob That isn't Working
If your key fob does not work, you can fix it by following just a few steps. First, ensure that it's not your backup remote.
If your backup remote cannot unlock and lock the doors of your car, it is most likely that the primary remote is not working. The most common causes of key problems with your car remote are battery or circuitry issues.
Battery
The battery inside the key fob may wear out over time. It is simple to replace a battery. However it is essential that you use the correct type. You can check the owner's manual or contact the manufacturer to find out the right type. It is recommended to inspect the battery compartment carefully, as dead batteries sometimes leak caustic chemicals that can 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 the buttons seem stuck or damaged it could be necessary to take the remote apart and rework its components. You can also try reprogramming your car to recognize the new key fob.
Buttons
From repeated use, key fobs could get dirty and worn. This is not uncommon however, it can cause buttons to cease working or require a very hard press for them to work. This can be extremely frustrating, especially if you are away from home and you need to start your vehicle. Fortunately, even worn-out or damaged buttons can be fixed with a bit of time and some of the materials you have in the house.
First, make sure the batteries are up correctly and that the indentation on the back of the button is filled. Take the remote apart and inspect the circuit board. Examine for indications of rust or other signs the buttons are worn or damaged. For example, conductive paint may be missing. Use a Q-tip dipped in alcohol to 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 painting and prevent the button firing when pressed.
Also, be sure to check the battery connector's terminals to ensure a loose solder connection. Soldering them back into place will restore the button's functionality if this is the case. You can apply the same process to restore functionality to any other loose connection within the fob.
If, for instance, any of the buttons made of rubber on the front of the key fob have stopped working or require a very hard press to work it is likely the graphite disks at the back of the button are deteriorating and need to be replaced. You can usually do this by rubbing a pencil over the disks. This will bring the button back to life.
If none of this is helpful or if the button doesn't respond to a hard push It could be the case that the circuit board has become damaged. This can sometimes be repaired 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
If the key fob buttons function the circuit board that is inside your remote might be dirty. A very thorough inspection is usually enough to fix this issue. The most common causes of dirty circuit boards are water and damaged cases. A broken case can allow water and other debris into the circuit board, which can cause it to short out. Water can also destroy pins and small connectors on the board, referred to as via's.
If you're able to open your key fob and don't mind making some mess, we can take the buttons out of their sockets and then solder new ones. It's also worth checking the battery terminal connections. They can become extremely dirty and if they're loose, the buttons might not work or may even remain in their down position. Soldering repair car key fob and buttons into place is usually enough to return a malfunctioning fob back to working.
Non-Remote transponder chips
Sealed non-remote transponder chips are much more durable than the remote fobs that contain them however they are still susceptible to being cracked by a hole that is drilled into them or over by a lawnmower or car door handle. Most of the time, non-remote transponder chip malfunctions can be attributed to blowing fuses.
If you're handy enough to remove a sealed non-remote 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 the Oreilly's and they usually have a RF frequency tester that will determine whether the key fob sending signals.
Programming
Key fobs take many abuses and aren't completely indestructible. They can break their connection with the receiver in your vehicle because of shocks or a low battery, requiring changing the program. A professional auto locksmith or dealer will be able to reprogram your key fob and get it working again. In the rarer case that resetting and repairing your key fob fails it could be the time to replace it completely.