A key fob allows a driver to operate some basic functions of a vehicle remotely. It most commonly has lock/unlock on it, but may also include a trunk/tailgate release, panic, engine start, or other features.
Replacing the Battery
Some key fobs are easily opened with a flat blade screwdriver, while others are more difficult to open. This common Ford/Lincoln/Mercury key fob can be opened with a small flat head screwdriver. The chip comes out of the button rubber piece and the battery can easily be accessed.