Systems, methods, and apparatuses provided herein relate to a controller for determining a pressure differential across a fluid filter by receiving inlet pressure data regarding a pressure of the fluid upstream of the filtering element, receiving outlet pressure data regarding a pressure of the fluid downstream of the filtering element, receiving engine speed data regarding a speed of the engine, receiving temperature data regarding a temperature of the fluid, and determining a pressure drop across the filtering element based on the inlet pressure data, the outlet pressure data, the engine speed data, and the temperature data.

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.

Disclosed is a method for determining reliability regarding misfire determination of cylinders of an engine, comprising detecting a pressure in an exhaust manifold for a set of operation parameters comprising a certain range of crank angles for a certain engine load and certain engine speed so as to, for an actual cylinder setup of the engine, create pressure sample value patterns for combustion and misfire conditions. A template course is created for the thus created pressure sample value patterns comprising a set of sample points. The pressure for the created template courses is normalized at a desired crank angle. Difference values are determined based upon differences between sample points and corresponding detected and the normalized pressure values. The determined difference values are summarized so as to determine whether a predetermined share of the summarized difference values lies above or below a predetermined threshold value indicating reliability regarding misfire determination.

Disclosed is a method for determining reliability regarding misfire determination of cylinders of an engine, comprising detecting a pressure in an exhaust manifold for a set of operation parameters comprising a certain range of crank angles for a certain engine load and certain engine speed so as to, for an actual cylinder setup of the engine, create pressure sample value patterns for combustion and misfire conditions. A template course is created for the thus created pressure sample value patterns comprising a set of sample points. The pressure for the created template courses is normalized at a desired crank angle. Difference values are determined based upon differences between sample points and corresponding detected and the normalized pressure values. The determined difference values are summarized so as to determine whether a predetermined share of the summarized difference values lies above or below a predetermined threshold value indicating reliability regarding misfire determination.

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 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 pressure sensor assembly includes an external housing unit; a sensor unit received within the external housing unit, the external housing unit has an external surface including a mounting surface; a sensing element mounted within the sensor unit and including a pressure-sensing surface; a substrate upon which the mounting surface is mounted; an air passage to enable air to impinge on the sensing element; and a filling passage, separate from the air flow passage, for the introduction of an encapsulation material onto the sensor unit, during assembly. The encapsulation material covers at least a part of the external surface of the sensor unit but does not cover the pressure-sensing surface of the sensing element which remains directly exposed to air within the air passage.

A pressure sensor assembly includes an external housing unit; a sensor unit received within the external housing unit, the external housing unit has an external surface including a mounting surface; a sensing element mounted within the sensor unit and including a pressure-sensing surface; a substrate upon which the mounting surface is mounted; an air passage to enable air to impinge on the sensing element; and a filling passage, separate from the air flow passage, for the introduction of an encapsulation material onto the sensor unit, during assembly. The encapsulation material covers at least a part of the external surface of the sensor unit but does not cover the pressure-sensing surface of the sensing element which remains directly exposed to air within the air passage.

A method for the diagnosis of engine misfires in an internal combustion engine having at least one cylinder, and includes the steps of: Determining exhaust back pressure values of the individual cylinders over at least two working cycles, correlating the exhaust back pressure values with the camshaft position and/or the working cycle, determining the exhaust back pressure maxima and/or exhaust back pressure minima per working cycle, comparing the exhaust back pressure maxima and/or exhaust back pressure minima between the individual cylinders—in the case of multiple cylinders—and/or to maximum and/or minimum values from previous working cycles and determining the deviations, comparing the deviations to a predetermined threshold value. The invention also relates to a control device for carrying out the method and a motor vehicle including such a control device.

A compact assembly for accurately measuring the air flow in an air intake duct of an internal combustion engine that is easy to manufacture and maintain. The assembly includes a housing with an inlet opening, an outlet opening, a channel with an inner wall defining a predetermined cross-sectional area and a closure member that is movably mounted in the channel between a closed and opened position. A first annular chamber is situated upstream from the closure member and a second annular chamber is placed downstream of the closure member. Each chamber has an inner chamber wall with a number of apertures that are in fluid communication with the channel. A first pressure sensor is connected to the first chamber for measuring a pressure, and a second pressure sensor is connected to the first chamber and the second chamber for measuring a difference in pressure.