### System Outline

Driving conditions are detected through indicators such as wheel speed, yaw rate sensor and steering angle signals, which are sent by ECUs, sensors and switches. The current delivered to the solenoid is controlled to provide the optimum torque to the rear wheels, in accordance with the driving conditions.

*Auto mode control

*The torque distribution to the rear wheels is increased at vehicle start, to ensure a stable start.

*The torque distribution to the rear wheels is reduced during slow speed driving to stabilize.

*During stable driving, the torque distribution to the rear wheels is discontinued, making the vehicle front wheel drive and reducing fuel consumption.

*During deceleration using the brakes, the 4 wheel drive is released to enhance the effect of the ABS/VSC control.

*Lock mode control

*The torque distribution to the rear wheels is fixed at the maximum level.

*At vehicle start, the torque distribution to the rear wheels is set at the maximum level to facilitate escape from the stuck condition.

*The mode automatically reverts to auto mode at a vehicle speed of 40 km/h or over.