Unlock Warning Switch Circuit: Description
WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.
The key unlock warning switch comes on when the ignition key is inserted into the ignition key cylinder and goes off when the ignition key is removed.
The theft warning ECU operates the key confinement prevention function while the key unlock warning switch is on.