Circuit Description
WARNING: This page is about a different car, the 2004 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
The unlock warning switch turns on when the key is inserted in the ignition key cylinder and the door courtesy switch turns on when the driver's door is opened, and the integration relay monitors both switches conditions. According to these switches conditions, the integration relay controls the door locking operation not to lock the doors while both switches are on, in order to prevent the key from being confined.