Power Source Circuit: Description
WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.
This circuit supplies power source voltage from the battery to terminal B of the steering lock ECU The diagnosis information of the steering lock ECU is transmitted to the tester via the certification ECU as the steering lock ECU is not connected to the CAN communication system