Abstract: A method for ascertaining a variable characterizing a flow rate of a fuel injector during an operation of an internal combustion engine, to which the fuel injector is assigned. At least two input values for a data-based model are ascertained, and at least one output value is determined with the aid of the data-based model, on the basis of which a value for the variable characterizing the flow rate of the fuel injector is ascertained. The data-based model combines at least two methods differing from one another for ascertaining a variable characterizing a flow rate of a fuel injector.

Abstract: A method for ascertaining a variable characterizing a flow rate of a fuel injector during an operation of an internal combustion engine, to which the fuel injector is assigned. At least two input values for a data-based model are ascertained, and at least one output value is determined with the aid of the data-based model, on the basis of which a value for the variable characterizing the flow rate of the fuel injector is ascertained. The data-based model combines at least two methods differing from one another for ascertaining a variable characterizing a flow rate of a fuel injector.

Abstract: In a method for adapting at least one injector of an injection system, in particular of a common-rail injection system of an internal combustion engine of a motor vehicle, where injections take place based on a characteristics map with at least two input variables and at least one output variable, a transition is carried out into a learning mode in which only discrete values are permitted for one of the at least two input variables of the characteristics map.

Abstract: In a method for adapting at least one injector of an injection system, in particular of a common-rail injection system of an internal combustion engine of a motor vehicle, where injections take place based on a characteristics map with at least two input variables and at least one output variable, a transition is carried out into a learning mode in which only discrete values are permitted for one of the at least two input variables of the characteristics map.

Abstract: In a method for operating a fuel injection system for an internal combustion engine of a motor vehicle, an output signal of a pressure sensor which characterizes a fuel pressure in a pressure accumulator is evaluated. An undesirably high fuel pressure in the pressure accumulator and/or a fault in the fuel injection system is/are inferred at the time when the output signal assumes a maximally possible value for at least a predefinable monitoring period.

Abstract: A method and a device for controlling an internal combustion engine are described. At least one injector meters a certain fuel quantity to the internal combustion engine at a certain point in time on the basis of a first signal and/or a second signal. At least the first and/or the second signal is/are corrected using a correction value. The correction value is adapted on the basis of at least one information value which is provided by at least one compensation procedure.