Stop Light Disconnection Warning
WARNING: This page is about a different car, the 2008 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
If any stop light wiring is faulty when the brake pedal is depressed with the ignition SW set at ON, the light failure sensor detects a voltage difference and is activated to turn on the rear lights warning light in the combination meter to warn the driver. The warning light is remained lit until the ignition SW is turned to the OFF position.