Abstract: The embodiment relates to a method for detecting a power-changing manipulation of an internal combustion engine (100), wherein the internal combustion engine (100) has an intake tract (110) and a pressure sensor (116, 118) which is arranged in the intake tract (110). The method has the following steps: acquiring a signal profile (440) over a specific time period by means of the pressure sensor (116, 118), providing a modelled signal profile (430) over the specific time period, from which periodically repeating modelled signal profile sections (432) which are characteristic of expected periodically repeating pressure changes in the intake tract (110) are ascertained, comparing a signal portion of an acquired signal profile section (442) with the corresponding signal portion of the corresponding modelled signal profile section (432) in order to detect the power-changing manipulation of the internal combustion engine (100).

Abstract: The embodiment relates to a method for detecting a power-changing manipulation of an internal combustion engine (100), wherein the internal combustion engine (100) has an intake tract (110) and a pressure sensor (116, 118) which is arranged in the intake tract (110). The method has the following steps: acquiring a signal profile (440) over a specific time period by means of the pressure sensor (116, 118), providing a modelled signal profile (430) over the specific time period, from which periodically repeating modelled signal profile sections (432) which are characteristic of expected periodically repeating pressure changes in the intake tract (110) are ascertained, comparing a signal portion of an acquired signal profile section (442) with the corresponding signal portion of the corresponding modelled signal profile section (432) in order to detect the power-changing manipulation of the internal combustion engine (100).

Abstract: A method and a device for checking the functionality of a crankcase ventilation system of an internal combustion engine is provided. The system has a low-load vent line and a high-load vent line between a crankcase outlet of a crankcase and a respectively associated introduction point into an air path of the internal combustion engine, in which method and device the pressure prevailing in the crankcase is measured by a crankcase pressure sensor and is compared with a crankcase pressure modeled on the assumption of a fault-free crankcase ventilation system, and in which method and device information items regarding the presence of a fault and of an associated fault location in the crankcase ventilation system are determined from the comparison result.

Abstract: Various embodiments may include a method for checking the plausibility of the functionality of a crankcase ventilation system of an internal combustion engine, wherein crankcase ventilation system has a crankcase, an intake tract equipped with an intake manifold, and a connecting line arranged between the crankcase and the intake manifold, the method comprising: detecting an occurrence of a negative load change; in response, comparing a measured intake manifold pressure with a modelled intake manifold pressure using acquired operating variables of the internal combustion engine and of a crankcase model; and determining on the basis of the comparison result whether the connecting line arranged between the crankcase and the intake manifold becomes blocked or drops out.

Abstract: Various embodiments may include a method for checking the plausibility of the functionality of a crankcase ventilation system of an internal combustion engine, wherein crankcase ventilation system has a crankcase, an intake tract equipped with an intake manifold, and a connecting line arranged between the crankcase and the intake manifold, the method comprising: detecting an occurrence of a negative load change; in response, comparing a measured intake manifold pressure with a modelled intake manifold pressure using acquired operating variables of the internal combustion engine and of a crankcase model; and determining on the basis of the comparison result whether the connecting line arranged between the crankcase and the intake manifold becomes blocked or drops out.

Abstract: A method for operating an exhaust gas aftertreatment system is provided that comprises at least one first SCR device and at least one second SCR device. Furthermore, a dosing device for reactant for supplying the SCR devices is provided upstream of the first SCR device in the exhaust gas flow direction. In one embodiment, a target overall efficiency ?Des of the SCR devices is specified. Using modeling of the exhaust gas aftertreatment system, depending on the target overall efficiency ?Des a target value ?1,Des is determined that represents the degree of charge of the first SCR device with reactant. The dosing of the reactant is adjusted accordingly to achieve the target value ?1,Des.

Abstract: A method for operating an exhaust gas aftertreatment system is provided that comprises at least one first SCR device and at least one second SCR device. Furthermore, a dosing device for reactant for supplying the SCR devices is provided upstream of the first SCR device in the exhaust gas flow direction. In one embodiment, a target overall efficiency ?Des of the SCR devices is specified. Using modeling of the exhaust gas aftertreatment system, depending on the target overall efficiency ?Des a target value ?1,Des is determined that represents the degree of charge of the first SCR device with reactant. The dosing of the reactant is adjusted accordingly to achieve the target value ?1,Des.

Abstract: A SCR catalyst system, comprising a first SCR catalyst (1) and a second SCR catalyst (2) which is disposed in the exhaust gas tract downstream of the first SCR catalyst (1). At least one metering device (12) for metering in a reducing agent solution is disposed in the exhaust gas tract upstream of a first SCR catalysis element (13) of said first SCR catalyst (1). The SCR catalyst system does not require a device for metering a reducing agent solution into a second SCR catalysis element (21) of the second SCR catalyst (2).

Abstract: A SCR catalyst system, comprising a first SCR catalyst (1) and a second SCR catalyst (2) which is disposed in the exhaust gas tract downstream of the first SCR catalyst (1). At least one metering device (12) for metering in a reducing agent solution is disposed in the exhaust gas tract upstream of a first SCR catalysis element (13) of said first SCR catalyst (1). The SCR catalyst system does not require a device for metering a reducing agent solution into a second SCR catalysis element (21) of the second SCR catalyst (2).