FOUR WHEEL DRIVE CONTROL SYSTEM GENERAL

  1. OUTLINE

    1. A compact and lightweight full-time 2-speed VF4BM transfer is used.

    2. The 4WD control ECU actuates and controls the 2 shift motors in the transfer shift actuator assembly. This causes the VF4BM transfer to switch the transfer gear ratio between high and low and the center differential between free and lock.

    3. On the models with 1GR-FE or 1KD-FTV engine, the transfer position switch is used to switch the transfer gear ratio between high and low, and the center differential lock switch is used to switch the center differential between free and lock. The optimal drive mode is selected from 4 drive modes (H4F, H4L, L4F and L4L) in accordance with road surface conditions by operating these switches, thus enabling a drive that makes optimal use of drive torque performance.

    4. On the models with 2TR-FE or 5L-E engine, the transfer position switch is used to switch the transfer gear ratio between high and low and the center differential between free and lock. The optimal drive mode is selected from 3 drive modes (H4F, H4L, and L4L) in accordance with road surface conditions by operating these switches, thus enabling a drive that makes optimal use of drive torque performance.

    5. A low viscosity oil is used, also improving fuel consumption.

  2. SPECIFICATION

    Transfer Type VF4BM
    Drive Type Full-time
    Transfer Gear Ratio High 1.000
    Low 2.566
    Reduction Gear Type Single Pinion Planetary
    Center Differential Gear Type TORSEN*1 Limited Slip Differential (LSD)
    Oil Capacity 1.4 Liters (1.5 US qts, 1.2 Imp. qts)
    Oil Viscosity SAE 75W
    Oil Type Toyota Genuine Transfer Gear Oil LF or equivalent
    Weight (Reference)*2 41.2 kg (90.8 lb)

    Tech Tips

    *1: TORSEN is a registered trademark of JTEKT Corporation.

    *2: Weight shows the figure with the fluid fully filled.

  3. MAIN FEATURES

    1. Drive Mode Features

      Drive Mode Features
      H4F (High Speed 4WD and Center Differential Free) Achieves a high level of stability in any speed range and road condition. Using its own movement , the center differential distributes drive torque optimally to the front and rear wheels, and absorbs the rotation difference between them during steering.
      H4L (High Speed 4WD and Center Differential Lock) Ensures a high level of driveability in snowy and icy areas, on sand and on rough roads. By switching the center differential to lock, the front and rear torque distribution is stopped and drive torque is accurately transmitted.
      L4F (Low Speed 4WD and Center Differential Free)* Ensures a large amount of drive torque and engine braking force by switching the transfer gear ratio to low. Using its own movement, the center differential distributes drive torque optimally to the front and rear wheels, and absorbs the rotation difference between them during steering.
      L4L (Low Speed 4WD and Center Differential Lock) Used when a large amount of drive torque is especially needed such as when freeing the vehicle from mud. By switching the center differential to lock, the front and rear torque distribution is stopped and drive torque is accurately transmitted.

      • *: Models with 1GR-FE or 1KD-FTV engine