A car fob, formally known as a key fob, is a small, handheld remote control device that locks, unlocks, and often starts your vehicle. It's the primary way most people interact with their cars today, replacing traditional metal keys. Modern fobs use radio frequency identification (RFID) to communicate securely with the car's computer system.
The most common functions are locking and unlocking the doors from a distance. Many fobs also have a button to open the trunk or liftgate. On vehicles with a push-button start system, the fob's presence is detected inside the car, allowing you to start the engine by pressing a button. Some advanced fobs even feature remote start, which lets you turn on the car's engine to heat or cool the interior before you get in.
Beyond convenience, a key fob is integral to your car's security. It contains a unique digital code that pairs with your specific vehicle. This prevents others from easily unlocking or starting your car. Most systems also have an immobilizer function; the engine will not start unless it recognizes the correct fob, which significantly reduces theft.
Replacing a lost key fob can be expensive, often costing several hundred dollars, as it requires specialized programming by a dealer or qualified locksmith. The battery inside is typically a small, user-replaceable coin cell (like a CR2032) that lasts for several years.
| Common Key Fob Function | Description |
|---|
| Lock/Unlock | Remotely secures or opens the vehicle's doors. |
| Panic Alarm | Activates the car's horn and lights to draw attention. |
| Trunk Release | Unlatches the trunk or liftgate remotely. |
| Remote Start | Starts the engine from outside to precondition the cabin. |
| Passive Entry | Doors unlock automatically when you touch the handle with the fob nearby. |
