Smart Unlock
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The smart unlock feature prevents the driver door from locking with the key in the ignition lock cylinder. When the vehicle security module receives a LOCK command from a door lock control switch, and the key is in the ignition lock cylinder with the driver door open, the vehicle security module commands the driver door to UNLOCK.