Patent ID: 8190351
Filing Date: 2012-05-29
Classification: F02D,G01M,Y02T

Abstract:
1. A diagnostic control apparatus for internal combustion engines that controls the fuel injection quantity to each cylinder and also diagnoses the presence and extent of variations in the air/fuel ratio or output in engine cylinders, wherein the diagnostic control apparatus measures the time required for the crankshaft to rotate to a specified angle for each cylinder; and along with deriving the 0.5 order component as the rotation fluctuation component for each two rotations of the crankshaft per each cylinder or the 1.0 order component as the rotation fluctuation component for each single rotation of the crankshaft based on the measured, required time; also makes a count of the number of times that the 0.5 order component or 1.0 order component deviated from the preset range in the period set for each cylinder; and diagnoses that an error has occurred in the output or in the air/fuel ratio for a particular cylinder when the count exceeds a specified value.