Brake Control Warning Light Remains ON: Description
WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.
If the ECU stores a DTC, the brake warning light / yellow (minor malfunction) comes on in the combination meter
The skid control ECU is connected to the No. 1 meter ECU via CAN communication.