Bentley Key Fob Replacement Today's key fobs do more than unlock or even start cars. They also serve as a major anti-theft device. It is crucial to keep them. Key fobs can stop working for a variety of reasons. The most frequent cause is a dead battery. It is easily replaced. Other reasons are damage to the receiver module, water issues or signal interference. https://numberfields.asu.edu/NumberFields/show_user.php?userid=1424143