Passive entry is a keyless access system that allows you to lock and unlock your car doors without physically using the key fob. As long as the key fob is on your person—in your pocket or bag—you can simply grab the door handle to unlock the car and press a button on the handle to lock it. The system uses a low-frequency radio signal to communicate between the car and the key fob when you are within a specified range, typically 3 to 6 feet.
The core technology involves sensors in the door handles and a receiver in the car that constantly searches for the unique signal from your key fob. This is part of a broader system often called a Passive Keyless Entry (PKE) system. When paired with a push-button start feature, it creates a seamless experience where you never need to take the key out of your pocket to enter, start, and drive the vehicle.
The primary benefits are convenience and security. It’s incredibly handy when your hands are full with groceries or children. From a security standpoint, the signal is encrypted to prevent relay attacks, where thieves use devices to amplify the key fob's signal from inside your home to unlock the car parked outside. However, storing the key fob in a Faraday pouch or a metal container at home can provide an extra layer of security against such sophisticated theft attempts.
| Feature/Aspect | Details |
|---|
| Typical Operating Range | 3 to 6 feet (1 to 2 meters) from the door handle |
| Communication Technology | Low-frequency radio signal (RFID) |
| Commonly Paired With | Push-Button Start system |
| Standard Security Feature | Rolling code encryption to prevent code grabbing |
| Potential Vulnerability | Relay attack (amplifying the key fob's signal) |
| Countermeasure | Using a signal-blocking Faraday pouch or box |
| Power Source for Key Fob | Standard coin-cell battery (e.g., CR2032) |
| Battery Life | Typically 3 to 5 years with normal use |
