Driver Side Seat Belt Warning Light does not Operate: Description
WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition switch is ON, the center airbag sensor assembly communicates the status of the front seat inner belt assembly LH to the main body ECU using the CAN communication line. The main body ECU receives signals from the center airbag sensor assembly and transmits them to the combination meter assembly. When the seat belt is unfastened, the combination meter assembly flashes the driver seat belt warning light in the combination meter assembly. When the seat belt is fastened, the combination meter assembly stops flashing the front driver seat belt warning light.