Seat Illumination Circuit: Description
WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
The seat illumination can be canceled using the overhead junction block switch
The seat illumination is controlled by the main body ECU LH based on various signals received through BEAN communication
The main body ECU LH includes a MOS-FET (Metal Oxide Semiconductor - Field Effect Transistor) circuit that fades the seat illumination in and out by duty control
This MOS-FET circuit has an overheat protection function as a fail-safe If the main body ECU LH becomes excessively hot, the seat illumination turns off and remains off
Normal operation will resume when the conditions required to turn on the seat illumination are met again