Door Mirror Foot Light 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 turning on and off of the door mirror foot lights is controlled by the main body 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 door mirror foot lights 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 door mirror foot lights turn off and remain off
Normal operation will resume when the conditions required to turn on the door mirror foot lights are met again