Abstract: A method for monitoring a gas sensor (14) which comprises two electrochemical measuring cells (20, 30) and which is arranged in an exhaust tract (10) of an internal combustion engine (11), wherein the sensor elements (20, 30) exhibit a substantially identical sensitivity towards a first gas component and a different sensitivity towards a second gas component and are insensitive towards further gas components. In an operating state in which an exhaust gas stream at the gas sensor (14) contains less of the second gas component than of the first gas component a concentration of the first gas component is calculated from each of the sensor signals from the sensor elements (20, 30) and a defect in a sensor element (20, 30) is deduced from the concentrations of the first gas component.

Abstract: The invention relates to a method for monitoring a NOx sensor (10) having an oxygen-ion-conducting solid electrolyte and having at least one cavity (12), wherein at least one cavity (12) of the NOx sensor is flooded with a defined oxygen concentration during a self-diagnosis of the NOx sensor. The gradient of a pump current resulting therefrom is evaluated and, in the case of a deviation in comparison with reference values, possibly impaired dynamics of the NOx sensor are inferred.

Abstract: A method for monitoring a gas sensor (14) which comprises two electrochemical measuring cells (20, 30) and which is arranged in an exhaust tract (10) of an internal combustion engine (11), wherein the sensor elements (20, 30) exhibit a substantially identical sensitivity towards a first gas component and a different sensitivity towards a second gas component and are insensitive towards further gas components. In an operating state in which an exhaust gas stream at the gas sensor (14) contains less of the second gas component than of the first gas component a concentration of the first gas component is calculated from each of the sensor signals from the sensor elements (20, 30) and a defect in a sensor element (20, 30) is deduced from the concentrations of the first gas component.

Abstract: A method is presented for checking the functional capability of a nitrogen oxide sensor (10) which has a first chamber (12) and a second chamber (14), wherein the first chamber has a first oxygen pump cell (20) and the second chamber has a second pump cell (34), in a normal operating mode of the nitrogen oxide sensor (10), an oxygen concentration level in the first chamber is reduced to a predetermined first value with the first pump cell, and an oxygen concentration level in the second chamber is reduced to a second value with the second pump cell, said second value being lower than the first value.

Abstract: The invention relates to a method for monitoring a NOx sensor (10) having an oxygen-ion-conducting solid electrolyte and having at least one cavity (12), wherein at least one cavity (12) of the NOx sensor is flooded with a defined oxygen concentration during a self-diagnosis of the NOx sensor. The gradient of a pump current resulting therefrom is evaluated and, in the case of a deviation in comparison with reference values, possibly impaired dynamics of the NOx sensor are inferred.

Abstract: A method is presented for checking the functional capability of a nitrogen oxide sensor (10) which has a first chamber (12) and a second chamber (14), wherein the first chamber has a first oxygen pump cell (20) and the second chamber has a second pump cell (34), in a normal operating mode of the nitrogen oxide sensor (10), an oxygen concentration level in the first chamber is reduced to a predetermined first value with the first pump cell, and an oxygen concentration level in the second chamber is reduced to a second value with the second pump cell, said second value being lower than the first value.

Abstract: A method for monitoring a particulate filter in the exhaust duct of an internal combustion engine operated with gasoline, as a device for implementing the method are described. A first exhaust-gas temperature is determined upstream of the particulate filter and a second exhaust-gas temperature is determined downstream from the particulate filter, and a presence and/or a correct functioning of the particulate filter is inferred from a difference between the first and the second exhaust-gas temperature or from a differing time characteristic curve of the first and the second exhaust-gas temperature.

Abstract: A method for diagnosing a sensor element for detecting at least one fraction of a gas component of a gas in a measuring gas chamber, in particular a sensor element for detecting oxygen in an exhaust gas of an internal combustion engine. The sensor element includes at least one first electrode, to which the gas may be applied, and at least one second electrode, the first electrode and the second electrode being connected via at least one solid electrolyte. A diagnostic signal is applied between the first electrode and the second electrode, a response signal being detected between the first electrode and the second electrode.

Abstract: The present invention relates to a method for monitoring a pollutant conversion capacity of a catalytically coated, oxidizing exhaust gas aftertreatment component (29) in an exhaust gas system (13) of an internal combustion engine (15). A nitrogen oxide sensor (31, 32) is disposed in each case in the flow path of the exhaust gas upstream of and downstream of the oxidizing exhaust gas aftertreatment component (29), a capacity of said oxidizing exhaust gas aftertreatment component (29) for converting NO to NO2 being ascertained from a comparison of the two signals (Z?, Z?) of the nitrogen oxide sensors (31, 32). Additional independent claims relate to an open-loop and/or closed-loop control device (17), a computer program and a computer program product.

Abstract: A method for monitoring the capability of a catalytic converter to convert nitrogen monoxide into nitrogen dioxide in the exhaust gas of an internal combustion engine, the catalytic converter being arranged in an exhaust gas duct of the internal combustion engine and the catalytic converter being followed downstream by a collecting particle sensor. It is in this case provided that, in a monitoring cycle, a decrease in the particle loading of the particle sensor during the operation of the internal combustion engine under predetermined operating conditions is taken to conclude an adequate capability of the catalytic converter to convert from nitrogen monoxide to nitrogen dioxide.

Abstract: A procedure to diagnose a particle filter disposed in an exhaust gas area of an internal combustion engine as well as a device to implement the procedure is proposed. Provision is made to ascertain the degree of efficiency of the particle filter on the basis of the upstream particle flow occurring upstream in front of the particle filter and on the basis of the downstream particle flow occurring downstream behind the particle filter. The ascertainment of the degree of efficiency of the particle filter allows for an On-Board-Diagnosis of the particle filter, with which compliance with specified exhaust gas threshold values can be assured.

Abstract: A method for diagnosing a sensor element for detecting at least one fraction of a gas component of a gas in a measuring gas chamber, in particular a sensor element for detecting oxygen in an exhaust gas of an internal combustion engine. The sensor element includes at least one first electrode, to which the gas may be applied, and at least one second electrode, the first electrode and the second electrode being connected via at least one solid electrolyte. A diagnostic signal is applied between the first electrode and the second electrode, a response signal being detected between the first electrode and the second electrode.

Abstract: A method for operating an internal combustion engine in whose exhaust-gas region at least one SCR catalytic converter is disposed, which is acted upon by a reagent contributing to the NOx conversion in the SCR catalytic converter, and a device for implementing the method. The reagent level in the SCR catalytic converter is controlled or regulated to a predefined reagent setpoint level, which is specified to at least a maximum value, which corresponds to an SCR catalytic converter completely filled with reagent. In this way the SCR catalytic converter is always operated at the highest possible efficiency at which the highest possible NOx conversion takes place.

Abstract: Method for diagnosing a NOx readings recorder which acquires a NOx concentration in an exhaust gas tract of an internal combustion engine and comprises two measuring chambers (110, 120), wherein the exhaust gas to be measured is supplied to the first measuring chamber (110) and an oxygen concentration is set by means of a first oxygen ion pump current (IP1), wherein the second measuring chamber (120) is connected to said first measuring chamber (110) and wherein both measuring chambers are disposed in a solid electrolyte, the oxygen content in the second measuring chamber (120) is determined; the oxygen content is additionally determined by a separate device; the two values characterizing the oxygen concentration are compared and a defective sensor is then suggested if the oxygen concentration value determined in the second measuring chamber (120) deviates from the oxygen concentration value determined by the separate sensor device by a predeterminable magnitude.

Abstract: A method for metering a reagent which an emission control device situated in the exhaust duct of an internal combustion engine requires for removing at least one exhaust gas component from the exhaust gas and a device for executing the method are described. The fluid level of the reagent stored in a reagent tank is measured. The measured change in the fluid level is compared to at least one measure for the change in the fluid level calculated as a function of consumption. An error signal is output when the comparison result exceeds a predefined threshold value. This approach enables reliable information to be provided about the fluid level of the reagent in the reagent tank.

Abstract: The invention relates to a method for diagnosing a particle filter used for filtering particles out of the exhaust gas of an internal combustion engine, wherein a collecting particle sensor is disposed downstream of the particle filter in the direction of flow of the exhaust gas and wherein a measurement for the loading of the particle sensor is determined from an output signal of the particle sensor.

Abstract: A method for monitoring the capability of a catalytic converter to convert nitrogen monoxide into nitrogen dioxide in the exhaust gas of an internal combustion engine, the catalytic converter being arranged in an exhaust gas duct of the internal combustion engine and the catalytic converter being followed downstream by a collecting particle sensor. It is in this case provided that, in a monitoring cycle, a decrease in the particle loading of the particle sensor during the operation of the internal combustion engine under predetermined operating conditions is taken to conclude an adequate capability of the catalytic converter to convert from nitrogen monoxide to nitrogen dioxide.

Abstract: The present invention relates to a method for monitoring a pollutant conversion capacity of a catalytically coated, oxidizing exhaust gas aftertreatment component (29) in an exhaust gas system (13) of an internal combustion engine (15). A nitrogen oxide sensor (31, 32) is disposed in each case in the flow path of the exhaust gas upstream of and downstream of the oxidizing exhaust gas aftertreatment component (29), a capacity of said oxidizing exhaust gas aftertreatment component (29) for converting NO to NO2 being ascertained from a comparison of the two signals (Z?, Z?) of the nitrogen oxide sensors (31, 32). Additional independent claims relate to an open-loop and/or closed-loop control device (17), a computer program and a computer program product.

Abstract: Method for diagnosing a NOx readings recorder which acquires a NOx concentration in an exhaust gas tract of an internal combustion engine and comprises two measuring chambers (110, 120), wherein the exhaust gas to be measured is supplied to the first measuring chamber (110) and an oxygen concentration is set by means of a first oxygen ion pump current (IP1), wherein the second measuring chamber (120) is connected to said first measuring chamber (110) and wherein both measuring chambers are disposed in a solid electrolyte, is characterized by the following steps: the pump voltage at an inner pump electrode in said first measuring chamber (110) and at an oxygen electrode (124) in said second measuring chamber (120) is reduced at a predeterminable operating point such that the oxygen content of the exhaust gas appears in the second measuring chamber (120) at a NOx measuring electrode (126) disposed therein; the oxygen content in said second measuring chamber (120) is determined; said oxygen content is additio

Abstract: The invention relates to a method for diagnosing a particle filter used for filtering particles out of the exhaust gas of an internal combustion engine, wherein a collecting particle sensor is disposed downstream of the particle filter in the direction of flow of the exhaust gas and wherein a measurement for the loading of the particle sensor is determined from an output signal of the particle sensor.