Abstract: The invention relates to a procedure for a switching pressure calculation at a metering valve of a fuel metering device for metering fuel into an exhaust gas system of a combustion engine with a component that is assigned to the exhaust gas system of the combustion engine for a regeneration, for a temperature impinge and/or for a thermo management, whereby the fuel is injected before this component in streaming direction of the exhaust gas. The invention concerns furthermore a corresponding device for implementing the procedure.

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: The invention concerns a procedure for controlling a metering device for metering fuel into the exhaust gas duct of a combustion engine for the regeneration of a particle filter, whereby the metering device supplies the fuel to the exhaust gas duct over a security valve, a first fuel pipe, a metering valve, a second fuel pipe and an injection check valve and whereby the pressure of the fuel is determined between the metering valve and the injection check valve in the second fuel pipe. It is thereby provided that an opening pressure of the injection check valve is determined from the pressure course between the metering valve and the injection check valve.

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: In a diagnosis method for performing a system diagnosis, e.g., a diagnosis of a physical system, the system is transferred into a plurality of predefined system states, a system characteristic of the system is acquired in at least two system states of the plurality of predefined system states so as to obtain a state-specific curve of the system characteristic, and the state-specific curve of the system characteristic is analyzed in order to obtain a diagnosis result.

Abstract: A method of determining a pressure at a dosing valve of a fuel metering device for metering fuel into an exhaust gas system of a combustion engine with a component of the combustion engine assigned to an exhaust gas system for a regeneration, a temperature impingement and/or a thermo management. The fuel is injected in a flow direction of the exhaust gas in front of the component, and metering of the fuel is determined by an injection valve from a cycle duration and a duty cycle relation for controlling a shut-off valve and the dosing valve depending on a difference pressure. The method includes determining a pressure before the dosing valve via acquisition and processing of at least one replacement value deduced from a pressure sensor signal of a pressure sensor arranged in a flow direction of the fuel behind the dosing valve for recording a measured pressure.

Abstract: The invention relates to a procedure for a switching pressure calculation at a metering valve of a fuel metering device for metering fuel into an exhaust gas system of a combustion engine with a component that is assigned to the exhaust gas system of the combustion engine for a regeneration, for a temperature impinge and/or for a thermo management, whereby the fuel is injected before this component in streaming direction of the exhaust gas. The invention concerns furthermore a corresponding device for implementing the procedure.

Abstract: The invention concerns a procedure for controlling a metering device for metering fuel into the exhaust gas duct of a combustion engine for the regeneration of a particle filter, whereby the metering device supplies the fuel to the exhaust gas duct over a security valve, a first fuel pipe, a metering valve, a second fuel pipe and an injection check valve and whereby the pressure of the fuel is determined between the metering valve and the injection check valve in the second fuel pipe. It is thereby provided that an opening pressure of the injection check valve is determined from the pressure course between the metering valve and the injection check valve.

Abstract: A method of determining a pressure at a dosing valve of a fuel metering device for metering fuel into an exhaust gas system of a combustion engine with a component of the combustion engine assigned to an exhaust gas system for a regeneration, a temperature impingement and/or a thermo management. The fuel is injected in a flow direction of the exhaust gas in front of the component, and metering of the fuel is determined by an injection valve from a cycle duration and a duty cycle relation for controlling a shut-off valve and the dosing valve depending on a difference pressure. The method includes determining a pressure before the dosing valve via acquisition and processing of at least one replacement value deduced from a pressure sensor signal of a pressure sensor arranged in a flow direction of the fuel behind the dosing valve for recording a measured pressure.

Abstract: A method of operating a reagent metering device, which contains a metering valve that is controlled by a metering signal, at which the reagent pressure actual value is detected in the reagent path between the metering valve and the injection valve, and at which a metering rate nominal value is specified, and a device for implementing the method. The method includes influencing of the metering signal (s_DV) with the aid of a measure for the detected reagent pressure actual value and with the aid of a stored relation between the measure for the reagent pressure actual value and a metering rate actual value. The method enables an operating of the reagent metering device with only one pressure sensor in the reagent path between the injection valve and the metering valve.