A determination device for an internal combustion engine executes a partial fuel cut-off process. The determination device determines that exhaust gas characteristics have deteriorated when the misfire rate of the internal combustion engine is greater than or equal to a determination threshold. The determination device sets the determination threshold to a first determination threshold when the calculated misfire rate is a misfire rate in a period of non-execution of the partial fuel cut-off process. Also, the determination device sets the determination threshold to a second determination threshold, which is less than the first determination threshold, when the calculated misfire rate is a misfire rate in a period of execution of the partial fuel cut-off process.

A determination device for an internal combustion engine executes a partial fuel cut-off process. The determination device determines that exhaust gas characteristics have deteriorated when the misfire rate of the internal combustion engine is greater than or equal to a determination threshold. The determination device sets the determination threshold to a first determination threshold when the calculated misfire rate is a misfire rate in a period of non-execution of the partial fuel cut-off process. Also, the determination device sets the determination threshold to a second determination threshold, which is less than the first determination threshold, when the calculated misfire rate is a misfire rate in a period of execution of the partial fuel cut-off process.

A PM sensor is arranged downstream of a one-side blocked filter that collects a particulate matter in exhaust gas of an engine, and first and second sensor abnormality diagnoses are executed based on output of the PM sensor. In the first sensor abnormality diagnosis, a filter-outflow PM amount (an amount of the PM flowing out from the one-side blocked filter) is estimated based on a working condition of the engine and a PM collection rate of the one-side blocked filter, and an occurrence of output abnormality of the PM sensor is determined by comparing a sensor-detection PM amount (an amount of the PM detected based on the output of the PM sensor) with the filter-outflow PM amount. In the second sensor abnormality diagnosis, an engine discharging PM amount (an amount of the PM discharged from the engine) is estimated based on a working condition of the engine, and an occurrence of output abnormality of the PM sensor is determined by comparing an increasing rate of the output of the PM sensor with an increasing rate of the engine discharging PM amount.

A method and a device for ascertaining a fluid injection quantity of an injection system. The injection system includes a high-pressure pump, a high-pressure region that adjoins the high-pressure pump, a pressure sensor, and an injector that is fed from the high-pressure region. The method includes detecting a measurement signal using the pressure sensor and segmenting a first pressure profile from the measurement signal. The first pressure profile characterizes the pressure profile prior to a fluid injection using the injector. The method also includes segmenting a second pressure profile from the measurement signal. The second pressure profile characterizes the pressure profile after the fluid injection using the injector. The method also includes performing a core density estimation using the first pressure profile and the second pressure profile, ascertaining a pressure difference, and ascertaining the fluid injection quantity using the pressure difference.

A system includes an aftertreatment system heater of an exhaust aftertreatment system coupled to an engine A controller coupled to the aftertreatment system heater is configured to determine a condition of an exhaust gas from an engine and compare the condition to a predefined threshold. If the condition of the exhaust gas does not meet the predefined threshold, the controller is configured to determine whether an engine operating condition is met for activating a cylinder deactivation operating mode for the engine. If the engine operating condition is met, the controller is configured to operate the engine in the cylinder deactivation operating mode by deactivating a cylinder of a plurality of cylinders. If the engine operating condition is not met, the controller is configured to activate the aftertreatment system heater to heat the exhaust gas.

A system includes an aftertreatment system heater of an exhaust aftertreatment system coupled to an engine A controller coupled to the aftertreatment system heater is configured to determine a condition of an exhaust gas from an engine and compare the condition to a predefined threshold. If the condition of the exhaust gas does not meet the predefined threshold, the controller is configured to determine whether an engine operating condition is met for activating a cylinder deactivation operating mode for the engine. If the engine operating condition is met, the controller is configured to operate the engine in the cylinder deactivation operating mode by deactivating a cylinder of a plurality of cylinders. If the engine operating condition is not met, the controller is configured to activate the aftertreatment system heater to heat the exhaust gas.

A controller for a common-rail injection system includes a plurality of fuel injectors, a common fuel supply line for the fuel injectors, a high-pressure pump for supplying the common fuel supply line with fuel, and a pressure sensor for determining the pressure in the common fuel supply line. A determination unit evaluates data of the pressure sensor and, from the pressure drop caused by an injection in the common fuel supply line, determines the fuel quantity actually injected during this injection or a value derived therefrom. An adaption unit uses the results of the determination unit in order to adapt the actuation of the fuel injectors. The determination unit carries out at least one test injection, and the actually injected fuel quantity or a value derived therefrom is effected by way of the test injection or injections.

An asymmetry cylinder de-activation (CDA) engine provided with a first, a second, a third and a fourth cylinder of which CDA apparatuses are mounted thereto respectively may include a crankshaft connected with pistons of each cylinder through a first, a second, a third and a fourth cranking journal respectively, and a controller configured to control operations of the CDA apparatuses, in which phase differences between cranking journals according to firing order may include 90±10 degrees and 270±10 degrees.

A microcomputer determines that an abnormality has occurred in calculation functions regarding calculation of an injection amount command value and the like, based on a deviation of the injection amount command value, in an increasing manner, from a monitoring injection amount. The microcomputer calculates, based on a cooling fluid temperature of an engine, a start-up injection amount such that the start-up injection amount becomes smaller when the cooling fluid temperature is high than when the cooling fluid temperature is low, and uses the start-up injection amount as the injection amount command value immediately after the completion of start-up of the engine. Besides, the microcomputer uses the smaller one of a start-up injection amount calculated this time and a monitoring start-up injection amount calculated last time, as a monitoring start-up injection amount that is used as the aforementioned monitoring injection amount immediately after the completion of start-up of the engine.

An ECU has a fuel pressure sensor that detects fuel pressure inside of a common rail. The ECU detects the fuel pressure at a predetermined frequency and calculates a drop amount of the fuel pressure in accordance with fuel injection by fuel injectors based on the detected fuel pressure. The ECU acquires a fluctuation amount of a fuel injection amount of each of the fuel injectors based on the drop amount of the fuel pressure and learns an injection characteristic of each of the fuel injectors, the injection characteristic indicating a correlation between the fuel injection amount and the fluctuation amount of the fuel injection. In a case in which a detection timing of the fuel pressure is within a fuel injection period of a predetermined fuel injector, the ECU disallows the learning of the injection characteristic using the fuel pressure detected in the fuel injection period.