CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINE

摘要

A control system for an internal combustion engine having a plurality of cylinders and a switching mechanism for switching between an all-cylinder operation in which all of the cylinders is operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. Operating parameters of a vehicle driven by the engine is detected. The all-cylinder operation or the partial-cylinder operation is performed according to the detected operating parameters. An oxygen concentration sensor is provided in an exhaust system corresponding to the at least one cylinder which is halted during the partial-cylinder operation. A failure of the oxygen concentration sensor is diagnosed in a predetermined operating condition including a fuel-cut operation of the engine upon deceleration. The partial-cylinder operation is permitted after completion of the failure diagnosis.