Two-step valve lifter control systems and methods

摘要

A valve lifter control system includes a valve lifter control module and a forced transition determination module. The valve lifter control module determines a desired lift state of a valve lifter based on at least one of engine speed and engine load. The forced transition determination module initiates a forced transition of the valve lifter from the low-lift state to the high-lift state based on manifold vacuum independently of the desired lift state.