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 make sure that it's not the backup remote.
If your backup remote cannot unlock and lock the doors of your car, then it is likely that the main remote isn't functioning. Most problems with car remote keys result from circuitry or battery issues.
Battery
The battery inside the key fob may get worn out over the course of time. remote key fob repair is relatively easy to replace batteries, but it is crucial to make sure that you use the right type 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 also crucial to examine the battery compartment, as batteries that are not working properly can release toxic chemicals that could damage the remote. If replacing the batteries doesn't solve the problem, it may be that there are other issues that require professional attention. If the buttons are damaged or stuck, for example it might be necessary to take the remote apart and rework each component. You could also try reprogramming your car to recognize the new key fob.
Buttons
From frequent use, key fobs could get dirty and worn. This is not atypical, but it can cause buttons to cease working or require a difficult press to get them to function. This can be a huge hassle, especially if you are away from home and you need to start your vehicle. Even malfunctioning or worn-out buttons can be fixed with a bit of time and the tools you already have at home.
First, make sure that the batteries are properly placed and that the indentation at the back of the button is filled. Then, open the remote with care and inspect the circuit board. Look for signs of corrosion or other signs that buttons are worn out or damaged, such as missing the conductive paint. Use a Q-tip dipped into rubbing alcohol to gently clean any membrane contact that is damaged 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 it is pressed.
Examine the battery connector's terminals carefully for any loose solder connections. If this is the case, soldering them back in place may bring back function to the button. You can use the same method to restore functionality to any other loose connection inside the fob.
Finally, if any of the buttons made of rubber on the front of the key fob stop working or require a very hard press to work it is likely that the graphite disks at the back of the button are deteriorating and need to be replaced. You can do this by rubbing a pen across the disks. This will bring the button back to life.
If none of this is useful or if the button doesn't respond to a hard press, then it may be that the circuit board has become damaged. It is possible to fix this issue by cleaning and re-soldering your fob, but you should have another spare in case it doesn't work.
Circuitry
The circuit board of the remote control could be dirty regardless of whether the buttons on the key fob function or not. A very thorough inspection is usually enough to fix this problem. The most common causes of dirty circuit boards is water and damaged cases. A damaged case could let water and other debris to get into the circuit board, causing it to short out. Water can also destroy pins and small connectors on the board, which are known as via's.
If you're skilled enough to open your key fob, and you don't mind making an mess, you can remove the buttons from their sockets and put in new ones. Also, you should check the connections between battery terminals. If they're loose, the buttons may not function properly or become stuck in their down position. Soldering the terminals and button's back into place is typically all that's required to return the key fob that is not working to working condition.
Non-Remote transponder chips
The non-remote chips that are sealed are more durable than their remote fobs, however they are susceptible to breaking if a hole is drilled in them or if a car door handle or lawnmower runs over them. The failure of the fuse is usually to blame for non-remote chips failures.
If you are not comfortable opening the key fob, you may remove the circuitboard and utilize a multimeter to determine if the diode is working properly. If you're not comfortable doing this, head to your local hardware store or Oreilly's, and they'll usually have an RF frequency tester that will tell you whether the key fob is transmitting a signal.
Programming
Key fobs take a lot of abuse and aren't completely indestructible. They can lose their pairing to the car's receiver due to shock or a low battery, requiring the reprogramming. A professional auto locksmith or a dealer in the main can reprogram the keyfob and get it functioning again. If resetting or repairing your keyfob does not work it may be necessary to replace it.