Abstract: In order to improve the steering and handling characteristics of a four wheel drive vehicle wherein at least one of the front and rear sets of wheels are provided with an auxiliary steering device, the steering condition of the vehicle is sensed and in the event that the steering is such that yaw can be easily induced the amount of power which is distributed to the front wheels is decreased relative to the amount prior the instant steering condition being established and vice versa.

Abstract: A vehicular height control system includes means for detecting road roughness condition on the basis of a vehicular height indicative signal which is produced by a vehicular height sensor. The control system also includes means for detecting the road roughness condition satisfying a predetermined condition for disabling vehicular height control. Disabling of vehicular height control keeps the control system free from fluctuation of vehicular height indicative signal value due to uneveness of the road surface.

Abstract: A suspension and steering control system includes a mode selection which enables a normal mode wherein the suspension is conditioned to produce a soft damping and sufficient power assistance to the steering to produce light steering characteristics and a sporty mode wherein the suspension is conditioned to produce a firm ride and the power assistance to the steering lowered to produce heavier steering characteritics. The system further includes an arrangement for sensing parameters which are related to the attitude of the vehicle and/or the suspension thereof and for (a) during the normal mode, temporarily conditioning the suspension to produce the firm ride characteristics if the attitude of the vehicle is apt to change beyond a predetermined amount, and for (b), during the sporty mode, temporarily conditioning the suspension to produce the soft ride in the event that no substantial changes in the vehicle attitude related parameters are sensed.

Abstract: An electronically controlled power steering system comprises a vehicle speed sensor, a steering wheel angle sensor, a power steering gear including a control valve, a bypass valve for regulating a flow rate of hydraulic fluid supplied to the control valve of the power steering gear in response to a control signal generated by a controller. The controller is operative responsive to sensor output signals of the sensors for generating the control signal. With the controller, the control signal is varied in response to the vehicle speed and the steering wheel angle when the steering wheel angle is less than a predetermined value, but this varying tendency of the control signal in response to the steering wheel angle is restrained when the steering wheel angle is not less than the predetermined value.

Abstract: A suspension control system employs a road sensor monitoring road roughness or smoothness and producing a road condition indicative signal. The control system also employs other sensor or sensors for monitoring at least one preselected suspension control parameter, such as vehicle speed, steering angular variation and so forth, other than road roughness. The suspension switches between relatively hard and relatively soft characteristics based on the preselected suspension control prameters. In order to make suspension control more precisely suited to the vehicle driving conditions, the control characateristics of the suspension system are adjusted depending upon the road condition.

Abstract: A vehicle height control system controls suspension assemblies to adjust the vehicle height within a predetermined height range. The vehicle height control system is further active to reduce differences in height at respective positions of the vehicle body so as to be within a predetermined acceptable height difference range.