Brake Control Warning Light does not Come ON [04/2018 - ]: Description
WARNING: This page is about a different car, the 2022 Toyota Avalon, 2021 Toyota Avalon, 2020 Toyota Avalon, and 2019 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.