INTAKE OXYGEN CONCENTRATION SENSOR DIAGNOSTIC SYSTEM FOR INTERNAL COMBUSTION ENGINE AND INTAKE OXYGEN CONCENTRATION SENSOR DIAGNOSTIC METHOD FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an intake oxygen concentration sensor diagnostic system for an internal combustion engine and an intake oxygen concentration sensor diagnostic method for the internal combustion engine capable of more accurately diagnosing an intake oxygen concentration sensor checking whether it is normal.SOLUTION: A system 100 includes an internal combustion engine 1, an intake passage 11, an exhaust passage 21, a supercharger 30, an EGR device 40, an intake oxygen concentration sensor 16 and a controller 80. The controller 80 makes a first determination when the operating state of the internal combustion engine 1 is in a first operating region set in an EGR stop region. When a first flag indicating the determination result of the first determination is in an ON state, the intake oxygen concentration sensor 16 is diagnosed as normal.SELECTED DRAWING: Figure 1