Brake Warning Light Remains ON [08/2013 - ]: Description

WARNING: This page is about a different car, the 2014 Lexus ES 300h. 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.

If any of the following is detected, the brake warning light / red (malfunction) remains on:

The skid control ECU (brake booster with master cylinder assembly) connector is disconnected from the brake booster with master cylinder assembly.
The brake fluid level is insufficient.
The parking brake is applied.
EBD operation has been disabled.