GENERAL INFORMATION




  • The ASC system integrates the traction control function and active stability control function.
  • When TCL detects the slip of the driving wheel (ex. during startup on low µ road), it automatically applies the brakes to the slipping driving wheel. At the same time, TCL reduces the engine output and prevents the wheel spin when it determines that the engine torque is too high for the road surface µ.
  • When the ASC determines that the vehicle is in a dangerous condition, it reduces the engine output and applies brake force to four wheels independently to control the vehicle behaviour, avoiding the critical state.
  • Fail-safe function assures the security.
  • Serviceability improvement
  • For wiring harness saving and secure data communication, the CAN* communication has been adopted as a tool of communication with another ECU.
note
  • *For more information about CAN (Controller Area Network), refer to GROUP 54C .
  • ABS and ASC are controlled by ASC-ECU.

CONSTRUCTION DIAGRAM





MAIN COMPONENTS AND FUNCTIONS
Name of part
 Number
 Functional description
Sensor
 Wheel speed sensor
 1
 Outputs the frequency signal in proportion to the rotation speed of each wheel to ASC-ECU.
Magnetic encoder for wheel speed detection
 2
 The wheel speed sensor is a pulse generator. When the magnetic encoder for wheel speed detection (a plate on which north and south pole sides of the magnets are arranged alternately) rotates, it outputs frequency pulse signal in proportion to each wheel speed.
Stop lamp switch
 3
 Outputs the signal indicating whether the brake pedal is depressed or not to ASC-ECU.
G & yaw rate sensor
 4
 Detects longitudinal and lateral acceleration of a vehicle, and outputs signal to ASC-ECU via the CAN line.
Steering wheel sensor
 5
 Detects the steering angle of the steering wheel, and outputs signal to ASC-ECU via the CAN bus line.
ASC OFF switch
 6
 Outputs the ON/OFF signal for TCL/ASC to ASC-ECU.
Brake fluid pressure sensor
 7
 Integrated into the hydraulic unit, and outputs the signal for the brake fluid pressure in the master cylinder to ASC-ECU.
Actuator
 Hydraulic unit
 8
 Drives the solenoid valve using the signal from ASC-ECU, and controls the brake fluid pressure for each wheel.
ABS warning lamp
 9
 Informs the driver of the system status by illuminating, flashing, or turning off the ABS warning lamp according to the signal from ASC-ECU.
ABS warning display
 10
 Informs the driver of the system status by illuminating or turning off the ABS warning display according to the signal from ASC-ECU.
Brake warning lamp
 11
 Used as the brake warning lamp for the parking brake, brake fluid level, and EBD control. Informs the driver of the system status by illuminating, flashing, or turning off the brake warning lamp according to the signal from ASC-ECU.
Brake warning display
 12
 Used as the brake warning display for the brake fluid level, and EBD control. Informs the driver of the system status by illuminating or turning off the brake warning display according to the signal from ASC-ECU.
ASC operation display
 13
 TCL function and ASC function use the same display. Depending on the signal from ASC-ECU, the ASC operation display informs the driver of the system status by flashing when the system operates and by illuminating when the system has malfunction.
ASC OFF display
 14
 Informs the driver of the system shutdown by illuminating by the signal from ASC-ECU. Informs the driver that the brake system overheats and the brake TCL stops by flashing the ASC OFF display for the duration of approximately 2 Hz.
ASC warning display
 15
 TCL function and ASC function use the same display. Depending on the signal from ASC-ECU, the ASC warning display informs the driver of the system status by illuminating when the system has malfunction.
Diagnosis connector
 16
 Sets the diagnosis code and establishes the communication with M.U.T.-III.
Engine-ECU
 17
 Controls the engine output based on the signal from ASC-ECU.
4WD-ECU
 18
 Outputs the drive status to ASC-ECU.
ASC control unit (ASC-ECU)
 19
 Controls the actuators (hydraulic unit) 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).

SCHEMATIC DIAGRAM




note Dashed lines indicate the CAN bus line.

TCL/ASC ELECTRICAL DIAGRAM