Key-in-Ignition Warning Chime
WARNING: This page is about a different car, the 2002 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
The key-in-ignition warning chime will sound when the driver door is opened with the key in the ignition switch and the ignition switch in OFF or ACC. It will continue to sound until the key is removed, the driver door is closed, or the ignition switch is turned to RUN or START.