Headlight Beam Level Control ECU Communication Circuit: Description
WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.
Body ECU sends signals that the headlight is ON and the daytime running light is on to the headlight beam level control ECU and operates the headlight beam level control system.
Headlight beam level control ECU receives the vehicle speed signal from the skid control ECU.