Footwell Light Circuit: Description
WARNING: This page is about a different car, the 2006 Lexus IS 350 and 2006 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
The main body ECU RH receives information regarding the door lock position switches, door courtesy switches, and engine switch, and turns on each footwell light.
This illumination setting can be canceled using the light control rheostat.