A hydraulic cam phaser includes at least one of an advance chamber and a retard chamber for receiving hydraulic fluid for advancing or retarding a rotational position of the camshaft. The hydraulic actuation system includes a hydraulic accumulator in selective communication with the at least one of the advance and retard chambers of the hydraulic cam phaser. A first system oil pump provides lubrication oil to the valvetrain system, and the hydraulic actuation system includes a second oil pump for supplying oil to the hydraulic accumulator. The second oil pump is controlled with a clutch device connecting the second oil pump to the engine drive system. The internal combustion engine includes a controller which controls actuation of the clutch device to actuate the clutch device during deceleration of the vehicle.