DESCRIPTION

- AWD control unit controls distribution of drive torque between rear-wheel drive (0:100) and 4-wheel drive (50:50) conditions according to road conditions.
- AWD control unit controls fix the drive torque distribution for front and rear wheels to stabilize the start-up on icy roads.
- Makes possible stable driving, with no wheel spin, on snowy roads or other slippery surfaces.
- Via each relevant sensor, AWD control unit judges road conditions and the vehicle cornering condition and distributes appropriate torques to the front wheel to prevent the tight-corner braking phenomenon, as well as to improve steering stability in a curve and vehicle stability during acceleration in a straight line and high speed driving.
- It transmits/receives each signal from the following AWD control unit via CAN communication line.

  Component parts | Function
  ABS actuator and electric unit (control unit) | This part mainly transmits the following signals to AWD control unit via CAN communication.
  - Vehicle speed signal (ABS)
  - Stop lamp switch signal (brake signal)
  - Yaw rate sensor signal
  - Side G sensor signal
  - Decel G sensor signal
  ECM | This part mainly transmits the following signals to AWD control unit via CAN communication.
  - Accelerator pedal position signal
  - Engine speed signal
  TCM | Transmits the transmission fluid temperature signal to AWD control unit via CAN communication.
  Combination meter | Transmits conditions of parking brake switch to AWD control unit via CAN communication.
  Steering angle sensor | Transmits the steering angle sensor signal to AWD control unit via CAN communication.

NOTE：

- When driving, if there is a large difference between front and rear wheel speed which continues for a long time, fluid temperature of drive system parts becomes too high and AWD warning lamp blinks quickly. (When AWD warning lamp blinks, vehicle changes to rear-wheel drive conditions.) Also, optional distribution of torque sometimes becomes rigid before lamp blinks quickly, but it is not a malfunction.
- If AWD warning lamp is blinking quickly, stop vehicle and allow it to idle for some time. Blinking will stop and AWD system will be restored.
- When driving, AWD warning lamp may blink slowly if there is a significant difference in diameter of the tires. At this time, vehicle performance is not fully available and cautious driving is required. (Continues until the engine is turned OFF.)
- If the warning lamp blinks slowly during driving but remains OFF after the engine is restarted, the system is normal. If it again blinks slowly after driving for some time, vehicle must be inspected.
- While the AWD warning lamp is blinking or illuminating, the vehicle enters rear-wheel drive condition or weak 4-wheel drive condition.

OPERATION PRINCIPLE
ELECTRIC CONTROLLED COUPLING

1.AWD control unit supplies command current to the electric controlled coupling (AWD solenoid).

2.Control clutch is engaged by electromagnet and torque is detected in control clutch.

3.The cam operates in response to control clutch torque and applies pressure to main clutch.

4.Main clutch transmits torque to front wheels according to pressing force.

- Torques transmitted to the front wheel are determined according to the command current.