Key Unlock Warning Switch
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition off. Locate and disconnect key unlock warning switch 2-pin electrical harness connector. See Figure. Using a DVOM, check for continuity across switch terminals. With key in ignition, continuity should exist. With key removed from ignition, continuity should not exist. If continuity is not as specified, replace key unlock warning switch.