System Outline
WARNING: This page is about a different car, the 2008 Lexus IS 350 and 2008 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
* To reduce the steering force required by the driver, the appropriate amount of assist current is calculated from the torque sensor signal and the vehicle speed signal and is then output to the motor.
* If an abnormality is found in the system, the power relay and motor relay (Built in the ECU) are shut off to stop the assistance, and the warning lamp (P/S) illuminates in the meter.