Abstract: A steering angle detecting system for a vehicle includes a sensor responsive to rotation of a steering wheel for generating angular pulses corresponding in number to the steering angle of the steering wheel. Another sensor generates a reference pulse at a predetermined angle of the steering wheel. The angular pulses are counted by a counter. The steering angle detecting system is determined to be abnormal if the counted value of the counter is not within a predetermined value range when the reference pulse is generated. Further, the rate of change of the counted value by the counter is detected, and the steering angle detecting system is determined to be abnormal if the detected rate of change of the counted value is greater than a predetermined value. Further, the steering angle detecting system is determined to be abnormal if the detected rate of change of the counted value has continued to be smaller than a predetermined value for a predetermined time period or longer.

Abstract: A driving wheel slip control device has a prohibition determining device for determining a prohibition region in which an engine control operation such as fuel suspension or an ignition stop is carried out, and a prohibition device for prohibiting the engine control operation even if an excessive or abnormal slip is generated. Prevention of a resonance and an engine stall are realized in addition to an expansion of a slip control region.

Abstract: A device for detecting a bad or bumpy road from a moving vehicle includes a plurality of wheel speed detectors for detecting the corresponding wheel speeds of a plurality of different wheels, an arithmetic circuit for calculating a difference between values detected in the individual wheel speed detectors, a filter, receiving outputs from the arithmetic circuit, for processing only components in a predetermined frequency band, and a determination circuit for determining if a vehicle is travelling on a bad road based on outputs from the filter. The device easily detects a bad road from a moving vehicle on the basis of outputs from said wheel speed detectors, without being affected by instantaneous variations in the wheel speeds.