Method for the functional diagnosis of a charge moving flap

The method for the function diagnosis of a charge movement valve in an internal combustion engine entails reducing the injection volume required for engine idling, measuring a base value for running irregularity, measuring a test value for running irregularity and comparing these values to detect a possible error function of the charge movement valve. In a full charge or partial charge regime, especially in the upper partial charge regime, the actual value of mass air flow directed to the engine is measured and compared with a nominal value in order to detect a possible error function of the charge movement valve. Independent claims are also included for the following: (A) a control unit in which the method is carried out; (B) a motor vehicle including the control unit and in which the aforesaid method is carried out; and (C) a computer program product to carry out the aforesaid method.