Sensor malfunction detecting system in vehicle control system

A sensor malfunction detecting system for a control system for a vehicle using output values from first, second and third sensors of three different types as control information, comprising:

• first calculating means for repeatedly calculating a first difference between an acceleration value based on an output from said first sensor and a value based on an output from said second sensor;
• second calculating means for repeatedly calculating a second difference between said acceleration value based on said output from said first sensor and a value based on an output from said third sensor;
• third calculating means for repeatedly calculating a third difference between said value based on said output from said second sensor and aid value based on said output from said third sensor;
• determining means for repeatedly determining whether said first difference calculated by said first calculating means, said second difference calculated by said second calculating means and said third difference calculated by said third calculating means are respectively within prescribed first, second and third ranges that are respectively calculated based on at least one of an initial variation error of one of said sensors, a temperature drift of one of said sensors, a degradation of one of said sensors, and a calculation accuracy of one of said calculating means;
• counter means for storing first, second and third count values corresponding to said first, second and third sensors, respectively, and for selectively updating said first, second and third count values in accordance with a result of said determining by said determining means, in which every time it is determined by said determining means that only one of said first, second and third differences is within said first, second and third prescribed ranges respectively, one of said count values corresponding to one of said sensors which is not related to calculation of said difference that was determined to be within said respective prescribed range is updated;
• and
• malfunction determining means for determining, when any one of said first, second and third count values updated by said counter means reaches a prescribed target value, that one of said sensors corresponding to said any one of said first, second and third count values that reaches said prescribed target value is malfunctioning;
• wherein said determining means and said counter means are respectively implemented by arithmetic operations in a processor.