Patent ID: 7588013

Claim:
A method for controlling an engine system that includes an engine which produces drive power by burning fuel; and a variable valve timing system which includes an actuator and which changes opening/closing timing of at least one of an intake valve and an exhaust valve provided in the engine, comprising: applying a torque, used to reduce an engine speed in a predetermined speed reduction pattern, to an output shaft of the engine, when a command to stop the engine is issued, changing the opening/closing timing by changing a rotational phase difference between a camshaft, which drives the valve of which the opening/closing timing is changed, and a crankshaft by a change amount corresponding to an operation amount of the actuator, when the engine is operating, setting a ratio of the change amount of the opening/closing timing with respect to the operation amount of the actuator to a lower value when the opening/closing timing is within a first phase region than when the opening/closing timing is within a second phase region, and determining whether a current state is a speed reduction enabled state in which it is possible to bring the opening/closing timing into the first phase region by the time the engine is stopped if reduction in the engine speed in the speed reduction pattern is started at a present moment that is after issuance of the command to stop the engine; and controlling an operation to reduce the engine speed after the command to stop the engine is issued, based on a result of a determination as to whether the current state is the speed reduction enabled state.