Methods and systems are provided for monitoring a fuel injector of an internal combustion engine. In one embodiment, a method includes: receiving a set of feature data, the feature data sensed from a fuel injector during a fuel injection event; processing, by a processor, the set of feature data with a decision tree model to generate a prediction of a fault status; and selectively generating, by the processor, a notification signal based on the prediction.

A multilayer component is disclosed. In an embodiment, a multilayer component includes a main body having a plurality of alternately arranged ceramic layers and inner electrodes and at least two outer electrodes for electrically contacting the inner electrodes, wherein the at least two outer electrodes have a different polarity, and wherein the outer electrodes have a different geometric shape and/or a different size and/or a different arrangement at an outer surface of the main body for identifying the different polarity.

A method of determining the nature of a fault in the operation of a hydraulic fuel injector includes sending an actuation pulse to an actuator of the injector, the actuation pulse being above the minimum drive pulse of the injector. The method also includes analyzing a signal from an accelerometer of the injector to determine if there is a high frequency vibration component subsequent to the end of the activation pulse. The method also includes determining the functionality of a needle control valve of the injector dependent on the outcome of analyzing the signal from the accelerometer.

An estimation unit estimates a fuel pressure on a discharge side of a high-pressure pump based on an amount of fuel injection with a fuel injection valve from a time point at which a detected fuel pressure changes from a higher status than a first pressure to a lower status, assuming that the fuel has not been discharged with the high-pressure pump. The determination unit determines that a relief valve is in an open status based on a dropping mode of the estimated fuel pressure and a dropping mode of the detected fuel pressure.

A fuel injector system includes an injector body having a proximal end and a distal end, the injector body defining a nozzle having an outlet. The injector system includes a spill valve fluidly connected to the outlet and having a spill valve member movable between an open position and a closed position. The injector system includes a control valve including a control valve member movable between an open position and a closed position. The injector system includes a check valve fluidly connected to the outlet, the control valve including a check valve needle movable between an open position and a closed position. The injector system also includes an electrical monitoring circuit configured to output a signal indicative of at least one of the open position or the closed position of the spill valve member.

A fuel injector interface device and associated method include an interface device having a plurality of input leads and a plurality of output leads. The input leads are communicatively linked to the fuel pressure sensor on the common rail of a vehicle fuel injection system. The output leads are communicatively linked to a display device such as a diagnostic scope. Circuitry positioned within the interface device detects the rail pressure signals, filters the signals, and outputs data to the display device representing a graphical depiction of the same. A method of using the interface device includes generating the signals, mapping the signals to an individual fuel injector of the vehicle's engine cylinder and determining fluctuations in the strength of the displayed signals to determine anomalies in a particular fuel injector.

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.

The present invention relates to an injector for injecting fuel, comprising an injector housing, a movable nozzle needle which is arranged in the injector housing and has a nozzle needle tip, a nozzle needle seat for receiving the nozzle needle tip, and a mechanical switch which upon contact of the nozzle needle tip with the nozzle needle seat assumes a closed state and upon interruption of the contact assumes an open state, wherein the injector is provided with an input line and an output line for actuating a movement of the nozzle needle, and the switch includes a first terminal and a second terminal. The injector is characterized in that the first terminal of the switch is connected to the input line and the second terminal of the switch is connected to the injector housing.

A method for monitoring a pressure sensor in a direct injection system including at least one common rail, a high-pressure fuel pump, a hydraulic circuit connecting the high-pressure pump to the common rail, a passive pressure-limiting valve connected to the hydraulic circuit, configured to open once the pressure in the hydraulic circuit is greater than a threshold pressure, so as to discharge the fuel, including the steps of detecting the opening of the pressure-limiting valve, measuring the pressure P.sub.MES corresponding to the time of opening of the pressure-limiting valve and comparing the measured pressure P.sub.MES to the threshold pressure P.sub.1 in order to detect a drift in the pressure sensor.

A method for operating a fuel injection system for a vehicle is provided. In particular, the fuel injection system includes an injection nozzle having a nozzle body, a nozzle orifice and a nozzle needle movable in the nozzle body. The method including: measuring an actual injection timing of the injection nozzle during injection based on an electrical signal generated by the nozzle needle through an electric contact with the nozzle body so that the electrical signal identifies an open state and a closed state of the injection nozzle; calculating a deviation of the actual injection timing from a scheduled injection timing of the fuel injection system; and controlling the injection nozzle by adjusting injection parameters of the injection nozzle based on the evaluated deviation.