Steering Column - Variable Gear Ratio Steering System

SYSTEM DIAGRAM

Part 1:

Part 2:

HINT:
*1: Warning information signals are transmitted via the following route:
Steering control ECU -> (CAN) -> Power steering ECU -> (CAN) -> Gateway ECU -> (BEAN) -> Combination meter

SYSTEM DESCRIPTION
1. GENERAL DESCRIPTION
(a) The VGRS (Variable Gear Ratio Steering) system controls the steering angle in accordance with vehicle speed. The system is controlled by the steering control ECU which operates the steering actuator mounted on the steering intermediate shaft. The operating angle of the steering actuator is added to the steering angle of the intermediate shaft in order to vary the turning angle of the front wheels in accordance with vehicle speed.
(b) When the VGRS system is operating normally, the steering wheel can be turned approximately 2.7 turns from lock to lock, with the engine running and the vehicle stopped.
(c) If a malfunction occurs in the VGRS system, steering actuator operation will immediately stop and the input and output shafts will be directly connected to enable the conventional steering mechanism to operate, maintaining steering function (fail-safe). At the same time, the master warning light (VGRS) will come on to inform the driver of the malfunction.
2. FUNCTIONS OF COMPONENTS
(a) Functions of VGRS system components