GENERAL INFORMATION


Vehicle-speed sensitive electric power steering (whole range type) has been adopted. This system allows a light steering force during stationary steering manoeuvre or low speed driving, and a moderate steering force during medium or high speed driving.
For vehicles with this system, the electric power steering-ECU controls the motor current according to the vehicle speed and steering force of the steering wheel.
CAN (Controller Area Network) communication has been adopted in order to communicate with another ECUs for obtaining necessary information related to this control, achieving wiring harness saving and secure data communication.
note For more information about CAN, refer to GROUP 54C - General information .

SPECIFICATIONS


Item
 Specification
Motor
 Type
 Permanent magnetic field type
Rated voltage V
 DC12
Rated current Arms
 50
Torque sensor
 Type
 Noncontact type (Inductance detection type)
Electric power steering-ECU
 Control type
 Microcomputer control (16 bit)
Rated voltage V
 DC12

GENERAL DESCRIPTION ON SYSTEM




To improve operational reliability, the dual-circuit system has been adopted for the torque sensor. If any malfunction occurs in the electric power steering system, the fail-safe function of the electric power steering-ECU is activated, and the output current of the electric power steering-ECU applied to the motor is turned off. At the same time, the steering system enters manual mode, and informs a driver of the system malfunction by illuminating the warning lamp on the combination meter. The warning lamp illuminates when the following malfunctions occur: open circuit in the electric power steering system wiring harness, poor connection, malfunctions in the electric power steering-ECU, motor, or sensors.

ELECTRICAL PARTS AND FUNCTIONS


Parts Name
 Description about functions
Sensor
 Vehicle speed sensor (ABS-ECU or TCL/ASC ECU)
 Sends the vehicle speed signal to the electric power steering-ECU.
Torque sensor
 Detects a steering force, converts it into the voltage signal, and then sends the signal to the electric power steering-ECU.
Actuator
 Motor
 Generates assist torque by the steering operation to the steering gear using the signals sent from the electric power steering-ECU.
Electric power steering warning lamp
 Warns a driver of the system malfunction using the signal sent from the electric power steering-ECU.
Electric power steering-ECU
 Controls the actuators (motors) based on the signals sent from sensors.
Controls the self-diagnostic function and fail-safe function.
Controls diagnostic function (Compatible with M.U.T.-III).

SYSTEM CONFIGURATION




note Dashed lines indicate CAN-bus lines.
Engine-A-M/T-ECU*Engine Automated Manual Transmission Electronic Control Unit