Patent ID: 8812220
Filing Date: 2014-08-19
Classification: F02D,F02M,Y02T

Abstract:
1. A diagnostic apparatus for an internal combustion engine, comprising: an EGR portion capable of executing an individual-cylinder EGR in which EGR gas is distributed and supplied individually to cylinders of the internal combustion engine; a knock detection portion programmed to detect a knock index value that represents a degree of knocking, separately for each of the cylinders; an abnormality detection portion programmed to determine a presence or an absence of a variation abnormality, in which air/fuel ratios of the cylinders vary among the cylinders, during execution of the individual-cylinder EGR by the EGR portion, and programmed to pinpoint an abnormal cylinder when determining that the variation abnormality is present, and programmed to calculate an imbalance index value that represents degree of variation regarding the abnormal cylinder; and an abnormality location pinpointing portion programmed to pinpoint an abnormality location in the abnormal cylinder based on the imbalance index value and the knock index value of the abnormal cylinder.