Self-diagnosing apparatus and method for determining occurence of failure in inner cylinder pressure responsive sensor applicable to engine combustion detecting/controlling system

摘要

In a self-diagnose apparatus and method for detecting an occurrence of failure in any one of a plurality of inner pressure responsive sensors due to a variety mode of failures, an integral value IMEP.sub.i within a predetermined integral interval of an inner cylinder pressure P for each engine cylinder is calculated, under an engine steady- state driving condition, a weight mean value BGIMEP.sub.i for each engine cylinder of the integral value IMEP.sub.i and a weight mean value TBGIMP for all cylinders are calculated, respectively, and a deviation JGIMEP between BGIMEP.sub.i and TBGIMP is calculated. If JGIMEP≧SLSNS (threshold value), the self-diagnose apparatus and method determine that any one of the inner cylinder pressure responsive sensors which corresponds to one of the cylinders which indicates the result of JGIMEP≧SLSNS has failed.