Key Unlock Warning Switch
WARNING: This page is about a different car, the 2000 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect key unlock warning switch 2-pin connector (located in steering column, near ignition switch). With key in ignition, check continuity between switch terminals No. 1 and 2. Continuity should exist. With key removed from ignition, check continuity between terminals No. 1 and 2. Continuity should not exist. If continuity is not as specified, replace key unlock warning switch.