Method and Control Unit for Diagnosing a Valve Lift Adjustment System of an Internal Combustion Engine

摘要

A method assesses the functional capability of a gas exchange valve lift adjuster of an internal combustion engine as a function of a measure of rotational oscillation amplitudes of a camshaft. The measure of the rotational oscillation amplitudes is formed repeatedly. In a situation in which the gas exchange valve lift adjuster is to change the valve lift, it is checked whether a change in the measure of the rotational oscillation amplitudes occurs. The gas exchange valve lift adjuster is assessed as being functional if a measure for the change is greater than a predetermined threshold value. A control unit is programmed to perform such steps.