Abstract: A control system for an internal combustion engine for driving a vehicle, which controls an output torque of the engine, is provided. In this control system, a rapid change in a demand torque of the engine is detected, and a feedforward correction amount is generated during a correction period which is substantially equal to a resonance period of a powertrain of the vehicle, from a time when the rapid change in the demand torque is detected. An output torque control amount of the engine is corrected with the feedforward correction amount. A torque change amount integrated value is calculated by integrating an amount of change in the demand torque, and the feedforward correction amount is generated according to the torque change amount integrated value.

Abstract: A control system for an internal combustion engine for driving a vehicle, which controls an output torque of the engine, is provided. In this control system, a rapid change in a demand torque of the engine is detected, and a feedforward correction amount is generated during a correction period which is substantially equal to a resonance period of a powertrain of the vehicle, from a time when the rapid change in the demand torque is detected. An output torque control amount of the engine is corrected with the feedforward correction amount. A torque change amount integrated value is calculated by integrating an amount of change in the demand torque, and the feedforward correction amount is generated according to the torque change amount integrated value.

Abstract: A control system for an internal combustion engine having at least one intake valve and at least one exhaust valve is disclosed. The control system includes a valve operating characteristic varying mechanism and a hydraulic control valve for controlling a hydraulic pressure to be supplied to the valve operating characteristic varying mechanism. The valve operating characteristic varying mechanism continuously varies an operating phase of the at least one intake valve and/or the at least one exhaust valve of the engine. A cleaning operation of the hydraulic control valve is performed in a predetermined operating condition of the engine. An intake air amount of the engine is controlled according to an operating condition of the valve operating characteristic varying mechanism when the cleaning operation of the hydraulic control valve is performed.

Abstract: There is provided a throttle control system and method for an internal combustion engine as well as an engine control unit, which are capable of controlling a throttle valve without any trouble even when the throttle valve is frozen. The throttle control system controls the degree of opening of the throttle valve. The opening of the throttle valve detected during control of the throttle valve to a fully-closed position at a start of the engine is set to a smallest angle. A temperature of the throttle valve is detected. A lower limit value of the target degree of opening is set to a degree of opening larger than the detected smallest angle of the throttle valve, when the detected smallest angle is larger than a predetermined degree of opening and at the same time the detected temperature of the throttle valve is lower than a predetermined temperature.

Abstract: A controller provided in accordance with the invention determines a failure of a thermostat that opens and closes a passage through which cooling water circulates between a radiator and an engine. The controller prohibits the failure determination if a water temperature of the engine decreases by more than a predetermined amount during a predetermined period from the time when a rotational speed of the engine exceeds a predetermined rotational speed. Thus, when the thermostat opens due to a high rotational speed of the engine, the failure determination is prohibited. Therefore, it is avoided that the thermostat operating normally is judged to be faulty.

Abstract: A control system for an internal combustion engine having at least one intake valve and at least one exhaust valve is disclosed. The control system includes a valve operating characteristic varying mechanism and a hydraulic control valve for controlling a hydraulic pressure to be supplied to the valve operating characteristic varying mechanism. The valve operating characteristic varying mechanism continuously varies an operating phase of the at least one intake valve and/or the at least one exhaust valve of the engine. A cleaning operation of the hydraulic control valve is performed in a predetermined operating condition of the engine. An intake air amount of the engine is controlled according to an operating condition of the valve operating characteristic varying mechanism when the cleaning operation of the hydraulic control valve is performed.

Abstract: There is provided a throttle control system and method for an internal combustion engine as well as an engine control unit, which are capable of controlling a throttle valve without any trouble even when the throttle valve is frozen. The throttle control system controls the degree of opening of the throttle valve. The opening of the throttle valve detected during control of the throttle valve to a fully-closed position at a start of the engine is set to a smallest angle. A temperature of the throttle valve is detected. A lower limit value of the target degree of opening is set to a degree of opening larger than the detected smallest angle of the throttle valve, when the detected smallest angle is larger than a predetermined degree of opening and at the same time the detected temperature of the throttle valve is lower than a predetermined temperature.

Abstract: A controller provided in accordance with the invention determines a failure of a thermostat that opens and closes a passage through which cooling water circulates between a radiator and an engine. The controller prohibits the failure determination if a water temperature of the engine decreases by more than a predetermined amount during a predetermined period from the time when a rotational speed of the engine exceeds a predetermined rotational speed. Thus, when the thermostat opens due to a high rotational speed of the engine, the failure determination is prohibited. Therefore, it is avoided that the thermostat operating normally is judged to be faulty.