Car Remote Key Repair Modern car remote keys are very useful and convenient, but they can be frustrating when they stop functioning. There are fortunately, simple fixes that are able to bring them back up and running. First, try replacing the battery. The majority of fobs are powered by lithium coin cells. These are cheap and easy to locate. Broken Electronics The electronic circuit board that is in your car key remote transmits and interprets signals to your vehicle. If the board is damaged the key fob won't