METHOD AND DEVICE FOR OPERATING AN INTERNAL COMBUSTION ENGINE

摘要

An internal combustion engine has a crankcase and an intake tract having a throttle valve, and a crankcase ventilation system having a switchable shut-off valve. Furthermore, a plurality of sensors are provided which each detect different operating parameters allocated to the internal combustion engine and output a measurement signal representing the respectively detected operating parameter. At least one of the sensors outputs a measurement signal which is representative of a load variable of the internal combustion engine. As a function of the different detected operating parameters, at least one estimated load parameter is determined by means of a dynamic model and as a function of a deviation between the estimated load variable and the detected load variable a corrective value of a characteristic value is determined. The corrective value and the characteristic value are used within the dynamic model. To implement a diagnosis, one or a plurality of diagnosis switching cycles (DIAG_CYC) are controlled, in which the shut-off valve is set to a closed switched position for a predetermined first period of time and the shut-off valve is set to an open switched position for a predetermined second period of time. As a function of a change to the corrective value in response to the one or the plurality of diagnosis switching cycles, a diagnosis value (DIAGW) is determined which is representative of a shut-off valve being in a correct or in an incorrect state.