Abstract: Disclosed is a method and a device for predicting the failure time of the pressure limiting valve of a high-pressure fuel pump of a motor vehicle. The method includes measuring a characteristic parameter of the pressure limiting valve each time the motor vehicle has been switched off, determining and storing a variable determined by using the measured characteristic parameter, determining the time profile of the variable determined from the characteristic parameter, predicting the future profile of the variable determined from the characteristic parameter, and comparing the predicted future profile of the variable determined from the characteristic parameter with a predetermined wear limiting value. The comparison is to predict the time at which the predicted future profile of the variable determined from the characteristic parameter reaches the predetermined wear limiting value.

Abstract: A method according to the invention for checking the plausibility of the function of a pressure sensor in an injection system of an internal combustion engine includes acquiring a calibrated actuation profile, by which peak current values for opening at least one electrically actuatable injection valve are assigned to existing internal pressures. An existing internal pressure is measured in the form of an actual sensor pressure value by the pressure sensor. The method includes obtaining the electrical peak current value corresponding to the measured sensor pressure value from a calibrated actuation profile, such that the corresponding electrical peak current value acquired in this way is applied to the injection valve. Subsequently, an opening state of the injection valve is monitored in reaction to the applied electrical peak current value, and a functional state of the pressure sensor is assigned as a function of the opening state of the injection valve.

Abstract: Disclosed is a method and a device for predicting the failure time of the pressure limiting valve of a high-pressure fuel pump of a motor vehicle. The method includes measuring a characteristic parameter of the pressure limiting valve each time the motor vehicle has been switched off, determining and storing a variable determined by using the measured characteristic parameter, determining the time profile of the variable determined from the characteristic parameter, predicting the future profile of the variable determined from the characteristic parameter, and comparing the predicted future profile of the variable determined from the characteristic parameter with a predetermined wear limiting value. The comparison is to predict the time at which the predicted future profile of the variable determined from the characteristic parameter reaches the predetermined wear limiting value.

Abstract: A method according to the invention for checking the plausibility of the function of a pressure sensor in an injection system of an internal combustion engine includes acquiring a calibrated actuation profile, by which peak current values for opening at least one electrically actuatable injection valve are assigned to existing internal pressures. An existing internal pressure is measured in the form of an actual sensor pressure value by the pressure sensor. The method includes obtaining the electrical peak current value corresponding to the measured sensor pressure value from a calibrated actuation profile, such that the corresponding electrical peak current value acquired in this way is applied to the injection valve. Subsequently, an opening state of the injection valve is monitored in reaction to the applied electrical peak current value, and a functional state of the pressure sensor is assigned as a function of the opening state of the injection valve.