CONTROLLER FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a controller for an internal combustion engine capable of accurately determining failure of an oxygen concentration sensor attached to the internal combustion engine switching partial cylinder operation and whole cylinder operation. SOLUTION: Failure of the oxygen concentration sensor is diagnosed in a predetermined operation condition including a fuel supply shut-off operation condition for shutting off fuel supply to the internal combustion engine. Partial cylinder operation is permitted (S25) on condition that failure diagnosis of the oxygen concentration sensor ends (S23) and it is determined that the oxygen concentration sensor is normal (S24) as a result of the diagnosis. Consequently, failure diagnosis of the oxygen concentration sensor is performed during whole cylinder operation to perform accurate diagnosis. COPYRIGHT: (C)2005,JPO&NCIPI