Abstract: A method for operating an internal combustion engine having two or more cylinders to which fuel can be supplied via an injection valve, it being possible to carry out a measurement injection for a cylinder in order to determine and/or adapt a characteristic quantity of the injection valve, and all the cylinders being ignited in the course of an ignition cycle. To improve the operating characteristics, a measurement injection is carried out for those cylinders that are contained in a specifiable selected set selected from all the cylinders.

Abstract: A method for assessing an injection behavior of at least one injection valve of an internal combustion engine includes putting the internal combustion engine into a special operating mode defined by control parameters and operating the engine in the special operating mode during a diagnostic time period, at least one operating parameter of the internal combustion engine being determined at least during the diagnostic time period, and at least one quantity characterizing the injection behavior of the at least one injection valve being evaluated at least during a segment of the diagnostic time period and being evaluated on the basis of the at least one operating parameter.

Abstract: A method for activating an injector in a fuel injection system in an internal combustion engine, the fuel injection system including a plurality of injectors and a quantity of fuel injected with the aid of an injector being a function of the activation period of the injector. An injector-individual correction value for the activation period is ascertained for at least one injector as a function of a pressure and a temperature of the fuel to be injected and the activation for this injector takes place under consideration of the injector-individual correction value.

Abstract: A method for operating an internal combustion engine having two or more cylinders to which fuel can be supplied via an injection valve, it being possible to carry out a measurement injection for a cylinder in order to determine and/or adapt a characteristic quantity of the injection valve, and all the cylinders being ignited in the course of an ignition cycle. To improve the operating characteristics, a measurement injection is carried out for those cylinders that are contained in a specifiable selected set selected from all the cylinders.

Abstract: A method for assessing an injection behavior of at least one injection valve of an internal combustion engine includes putting the internal combustion engine into a special operating mode defined by control parameters and operating the engine in the special operating mode during a diagnostic time period, at least one operating parameter of the internal combustion engine being determined at least during the diagnostic time period, and at least one quantity characterizing the injection behavior of the at least one injection valve being evaluated at least during a segment of the diagnostic time period and being evaluated on the basis of the at least one operating parameter.

Abstract: A method for determining a concentration of alcohol in a fuel mixture, where a characteristic curve for a parameter describing the dynamics of an injector, by which the fuel mixture is injected in an internal combustion engine, is ascertained; and where the concentration of alcohol is determined in light of a course of the characteristic curve. The invention also relates to a method for operating an internal combustion engine and a system for determining a concentration of alcohol in a fuel mixture.

Abstract: A method for activating an injector in a fuel injection system in an internal combustion engine, the fuel injection system including a plurality of injectors and a quantity of fuel injected with the aid of an injector being a function of the activation period of the injector. An injector-individual correction value for the activation period is ascertained for at least one injector as a function of a pressure and a temperature of the fuel to be injected and the activation for this injector takes place under consideration of the injector-individual correction value.

Abstract: A method for determining a concentration of alcohol in a fuel mixture, where a characteristic curve for a parameter describing the dynamics of an injector, by which the fuel mixture is injected in an internal combustion engine, is ascertained; and where the concentration of alcohol is determined in light of a course of the characteristic curve. The invention also relates to a method for operating an internal combustion engine and a system for determining a concentration of alcohol in a fuel mixture.

Abstract: A method for operating an internal combustion engine, in particular, of a motor vehicle. The internal combustion engine includes an injector having a nozzle needle for injecting fuel into a combustion chamber of the internal combustion engine, as well as an output stage component. A desired signal is specified for a lift characteristic of the nozzle needle. The injector is activated by the output stage component. A lift signal is ascertained that corresponds to the actual lift characteristic of the nozzle needle. An actual signal is ascertained from the lift signal. A deviation signal is ascertained in response to a deviation of the actual signal from the desired signal.