Locking and unlocking Model S with your key fob is conveniently hands-free. Although you must be carrying a paired key fob, there is no need to use it. Model S has sensors around the vehicle that can recognize the presence of a key fob within a range of approximately six feet (two meters). Therefore, you can keep your key fob in your pocket or purse and press the door handle to unlock and extend the handle. When carrying your key fob with you, you can also open the trunk without having to use the key by pressing the liftgate's exterior switch. If Walk-Away Door Lock is enabled, Model S automatically locks when you exit and the key fob is no longer in range (see Walk-Away Door Lock). Passive locking and unlocking is automatically enabled when you pair your key fob to Model S.
Although you can use the same key fob with multiple vehicles, it can only be paired to one vehicle at a time. To activate a paired key fob to a different vehicle, touch the flat side onto the driver's side door pillar and click any button on the key fob to confirm.
NOTE: For increased security, passive locking and unlocking disables after being stationary for five minutes while within vehicle range when the vehicle is not in use (for example, you are standing outside your vehicle). In this situation, you must shake or press a button on the key fob to re-enable passive locking and unlocking.
Replacing the Key Fob Battery
Under normal use, the key fob has a battery that lasts for up to one year, depending on key fob version and selected vehicle settings. When the battery is low, a message displays on the touchscreen.
To replace the key fob battery:
1. With the key fob placed button side down on a soft surface, release the bottom cover, using a small flat- bladed tool.
2. Remove the battery by lifting it away from the retaining clips.
3. While avoiding touching the battery's flat surfaces, insert the new battery (type CR2330) with the '+' side facing up.
NOTE: Wipe the battery clean before fitting and avoid touching the battery's flat surfaces. Finger marks on the flat surfaces of the battery can reduce battery life.
NOTE: CR2330 batteries can be purchased from any retailer that sells batteries.
4. Holding the bottom cover at an angle, align the tabs on the cover with the corresponding slots on the key fob, then press the cover firmly onto the key fob until it snaps into place.
5. Test that the key fob works by unlocking and locking Model S.
WARNING: Key fob batteries contain a chemical burn hazard and should not be ingested. The key fob contains a coin cell battery. If the coin cell battery is swallowed, it can cause severe internal burns within two hours and can lead to death. Keep new and used batteries away from children. If the battery compartment does not close securely, stop using the product and keep it away from children. If you think batteries might have been swallowed or placed inside any part of the body, seek immediate medical attention.