Circuit Inspection
WARNING: This page is about a different car, the 2003 Lexus GS 430, 2003 Lexus GS 300, 2002 Lexus GS 430, and 2002 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
The key unlock warning switch goes on when the ignition key is inserted in the key cylinder and goes off when the ignition key is removed. The body ECU No. 2 operates the key confinement prevention function while the key unlock warning switch is on.