Abstract: A method for determining a filling level of a fluid tank in a motor vehicle, enables both a detection of an ascent or a descent of the motor vehicle with the aid of multiple pieces of position data ascertained in succession via a position determination system, and a plausibility check of the measuring value of the filling level sensor, in that a grade of an associated route section is ascertained for the ascertained position data, a selection of at least two route sections having different grades is carried out, and a measuring value of the filling level sensor to be expected is ascertained for each of them, and a comparison of the measuring values to be expected with the measured measuring values is carried out.

Abstract: A method is made available for monitoring a pressure sensor (18) in a pressure-controlled delivery and metering system for a liquid reactant of a catalytic converter, in particular of an SCR catalytic converter. The delivery and metering system is provided for delivering the reactant from a tank (10) and for metering the reactant via a pressure line (16) and a metering module (19). In order to monitor the pressure sensor (18) which is located in the pressure line (16), a flow rate measurement is carried out in the pressure line (16) and/or in a return path (17) taking into account the relationship between the pressure p and the corresponding flow rate v.

Abstract: A method for determining a filling level of a fluid tank in a motor vehicle, enables both a detection of an ascent or a descent of the motor vehicle with the aid of multiple pieces of position data ascertained in succession via a position determination system, and a plausibility check of the measuring value of the filling level sensor, in that a grade of an associated route section is ascertained for the ascertained position data, a selection of at least two route sections having different grades is carried out, and a measuring value of the filling level sensor to be expected is ascertained for each of them, and a comparison of the measuring values to be expected with the measured measuring values is carried out.

Abstract: A method is made available for monitoring a pressure sensor (18) in a pressure-controlled delivery and metering system for a liquid reactant of a catalytic converter, in particular of an SCR catalytic converter. The delivery and metering system is provided for delivering the reactant from a tank (10) and for metering the reactant via a pressure line (16) and a metering module (19). In order to monitor the pressure sensor (18) which is located in the pressure line (16), a flow rate measurement is carried out in the pressure line (16) and/or in a return path (17) taking into account the relationship between the pressure p and the corresponding flow rate v.

Abstract: A procedure for checking the functionality of a reducing agent pump (172) of a NOx-reduction system of a combustion engine (110) is thereby characterized, in that it is checked, whether the pump (172) reaches a default engine speed value in a defined time interval within defined limits.

Abstract: The invention relates to a method for detecting an error in a component assembly of a motor vehicle, the component assembly having a functional control unit and at least one function module to be controlled by the functional control unit as components. According to the method, a check is made by the functional control unit to determine whether a combination of individual errors is present for at least one component of the component assembly. When the combination of individual errors is thereby present, an occurrence of the error is verified by the functional control unit and a signal for implementing an emergency functional strategy is transmitted by said control unit to an engine control unit.

Abstract: A procedure for checking the functionality of a reducing agent pump (172) of a NOx-reduction system of a combustion engine (110) is thereby characterized, in that it is checked, whether the pump (172) reaches a default engine speed value in a defined time interval within defined limits.

Abstract: The invention relates to a method for detecting an error in a component assembly of a motor vehicle, the component assembly having a functional control unit and at least one function module to be controlled by the functional control unit as components. According to the method, a check is made by the functional control unit to determine whether a combination of individual errors is present for at least one component of the component assembly. When the combination of individual errors is thereby present, an occurrence of the error is verified by the functional control unit and a signal for implementing an emergency functional strategy is transmitted by said control unit to an engine control unit.