DYNAMIC TORQUE CONTROL AWD SYSTEM


  1. OUTLINE


    1. An MF1A type transfer that is compact and lightweight is used on AWD models.

    2. Dynamic Torque Control AWD is used on AWD models.

    3. Dynamic Torque Control AWD is a compact, lightweight and high performance AWD system that optimally controls the torque distribution to the front and rear wheels using an electromagnetic control coupling in the rear differential.

    4. The AWD system performs control in cooperation with the brake control system. The 4WD ECU assembly controls the drive torque distribution to the front and rear wheels in accordance with information received from the skid control ECU. These controls ensure a smooth acceleration and driving stability. For details, see the Brake Control/Dynamic Control Systems section.

  2. SPECIFICATION

    Transfer Type MF1A
    Gear Type Hypoid Gear
    Gear Ratio 0.439
    Transfer Ring Gear The No. of Teeth 41
    Transfer Driven Pinion Gear The No. of Teeth 18
    Oil Viscosity SAE 75W-85
    Oil Grade API GL-5
    Oil Type Toyota Genuine Differential Oil LT or equivalent
    Oil Capacity Liters (US qts, Imp. qts) 0.8 (0.85, 0.70)
    Weight (Reference)* kg (lb) 14.7 (32.4)

    *: The weight shown is the weight of the part fully filled with fluid.

  3. MAIN FEATURES


    1. Based on information provided by various sensors, the 4WD ECU assembly controls the amperage applied to the electromagnetic control coupling in order to distribute an appropriate amount of drive torque to the rear wheels when needed. The following describes the features and benefits of Dynamic Torque Control AWD:

      Feature Outline
      Traction performance Achieves stable start-off and acceleration performance.
      Driving stability performance Achieves stable cornering performance.
      Fuel economy Achieves better fuel economy by distributing an appropriate amount of drive torque to the rear wheels when needed.

    2. A differential lock switch has been provided. This enables the driver to select LOCK mode by operating the switch. The system optimally controls the torque distribution to the front and rear wheels in the respective modes

      Differential Lock Switch and Indicator Light Outline
      Off

      • Optimally distributes drive torque to the front and rear wheels.

      • Ensures optimal start-off performance during a start-off, based on information provided by various sensors.

      • Suppresses the tight corner braking phenomenon* during low-speed cornering.

      • Reduces the amount of torque distribution to the rear wheels and improves fuel economy when the system judges that the vehicle is traveling steadily.

      • Disengages the AWD during braking deceleration.
      On

      • Distributes the maximum torque limit to the rear wheels.

      • Distributes the maximum torque limit to the rear wheels during start-off.

      • Distributes optimal torque during low-speed cornering.

      • Disengages the AWD during braking deceleration.

      • Disengages the LOCK mode when the vehicle speed exceeds 40 km/h (25 mph).

      *: Tight corner braking phenomenon: a phenomenon in which an AWD vehicle may lurch and decelerate due to a rotational speed difference between the front and rear wheels, such as during low-speed cornering in AWD mode.

    3. The 4WD ECU assembly performs cooperative control with the skid control ECU, in order to control the drive torque distribution to the front and rear wheels in accordance with information received from the skid control ECU. These controls ensure smooth acceleration and driving stability.