Key Lock-in Prevention Function does not Work Properly: Description
WARNING: This page is about a different car, the 2007 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.
To prevent the key from being locked in the vehicle, the multiplex network body ECU prevents the doors from being locked by monitoring 2 switches: 1) the unlock warning switch, which turns ON when the key is inserted into the ignition key cylinder; and 2) the driver side courtesy light switch, which turns ON when the driver side door is opened.