CONTROL DEVICE AND CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE

摘要

An electronic control unit (60) for an internal combustion engine (10) that includes an engine-driven alternator (70) diagnoses on the bases of an air-fuel ratio correction amount in air-fuel ratio feedback control whether a rich abnormality that the air-fuel ratio of air-fuel mixture is excessively rich is occurring in a fuel injection system. When the state of charge of a battery (80) charged with electric power generated by the alternator (70) is higher than or equal to a predetermined value, charging control for setting a voltage generated by the alternator (70) at a voltage (V2) lower than a normal generated voltage is executed. When the state of charge of the battery (80) is higher than or equal to the predetermined value, charging control for charging the battery (80) at the voltage (V2) is prohibited when a degree of mixing of fuel in lubricating oil of the internal combustion engine (10) is higher than or equal to a predetermined degree.