Abstract: An internal combustion engine includes an intake air temperature adjustment apparatus that adjusts the temperature of intake air, and a control apparatus that operates at least the intake air temperature adjustment apparatus. When the internal combustion engine operates in a stoichiometric EGR mode, the control apparatus operates the intake air temperature adjustment apparatus so that the temperature of intake air entering a combustion chamber enters a first temperature region. When the internal combustion engine operates in a lean mode, the control apparatus operates the intake air temperature adjustment apparatus so that the temperature of intake air entering a combustion chamber enters a second temperature region that is a lower temperature region than the first temperature region.

Abstract: Methods and systems are provided for ventilating a crankcase in a boosted engine. An example method may include selectively enabling one of crankcase ventilation and aspirator motive flow via an electrically controlled valve, the aspirator motive flow being enabled in response to a demand for vacuum from a vacuum consumer. In this way, the crankcase of the boosted engine may be ventilated until the vacuum consumer demands vacuum.

Abstract: Provided are a valve stop mechanism capable of switching intake valves and exhaust valves of deactivated cylinders between an openable/closable state and a closed state, and an engine speed control unit which controls the engine speed. The engine speed control unit controls the engine speed in such a manner that the amount of change in the engine speed with respect to time is reduced, as compared with a case in which a specific condition is not satisfied, when the specific condition that switching by the valve stop mechanism is not completed, and that connection between an engine and a power transmission unit is released is satisfied after issuance of a switching request from one of a reduced-cylinder operation and an all-cylinder operation to the other thereof.

Abstract: The present invention relates to a compression-ignition direct-injection internal-combustion engine with a compression ratio ranging between 13.5 and 16.5 including a combustion chamber limited on one side by upper face (44) of a piston (16) comprising a projection (48) arranged in the center of a concave bowl (46) with at least two mixing zones (Z1, Z2), a fuel injection comprising at least one injector (30) projecting fuel in at least two fuel jet sheets (36, 38) with different sheet angles (A1, A2). The fuel injector comprises two rows of injection orifices (33a, 33b) arranged one above the other with the number of orifices of each row (Ninf, Nsup) is greater than or equal to ?4·Ns+14 and less than or equal to ?4·Ns+16 for the lower sheet or ?4·Ns+18 for the upper sheet. Ns is the swirl number of this engine with a swirl number less than 1.5.

Abstract: A method and apparatus for regenerating a Lean NOx Trap in an internal combustion engine is disclosed. The internal combustion engine includes a Lean NOx Trap, a turbocharger having a turbine. An electronic control unit is configured to execute a regeneration event of the Lean NOx Trap, and regulate a position of an actuator affecting a rotating speed of the turbine using a closed-loop control strategy of an air pressure into an intake duct downstream of a compressor of the turbocharger and upstream of a throttle valve during the execution of the regeneration event.

Abstract: An internal combustion engine is provided with an EGR device and is configured to be capable of executing an operation based on a first air-fuel ratio and an operation based on a second air-fuel ratio leaner than the first air-fuel ratio. In a case where an ECU decreases the amount of air flowing into a combustion chamber and decreases an EGR rate in response to a predetermined torque reduction request for the internal combustion engine, the ECU performs the operation based on the first air-fuel ratio in a case where an immediately preceding EGR rate immediately before the torque reduction request is made is lower than a first threshold and performs a stratified combustion operation based on the second air-fuel ratio in a case where the immediately preceding EGR rate is equal to or higher than the first threshold.

Abstract: An electronic control unit detects a manner of fluctuation of a fuel pressure with injection of fuel by a fuel injection valve with the use of a fuel pressure sensor, and calculates a tendency of deviation of an actual fuel injection characteristic of the fuel injection valve with respect to a basic fuel injection characteristic on the basis of a result of comparison between a detected temporal waveform and a basic temporal waveform. The tendency of deviation is reflected at a predetermined reflection rate (R) at the time of updating a learned value (Gij) for compensating for an individual difference of the fuel injection valve. The predetermined reflection rate (R) is increased when an accumulated value (D) of a vehicle travel distance is shorter than a predetermined value (Dth) as compared with when the accumulated value (D) is longer than or equal to the predetermined value (Dth).

Abstract: Provided is an internal combustion engine including a sparkplug disposed in the vicinity of the center portion of an upper wall surface of a combustion chamber. Tumble flow generated during lean burn operation is controlled such that the tumble flow shape changes according to the engine rotation speed between a first tumble shape (usual tumble shape) in which the flow direction of a gas around the sparkplug at the time of ignition is direction from an intake valve side toward an exhaust valve side in a latter half of a compression stroke, and a second tumble shape (? tumble shape) in which the flow direction of the gas is reversed in the latter half of the compression stroke from the direction from the intake valve side toward the exhaust valve side to the direction from the exhaust valve side toward the intake valve side.

Abstract: A multicylinder engine includes a plurality of intake ports, a plurality of in-cylinder injectors, and an electronic control unit. The electronic control unit is configured to initially set a value of a control parameter of the multicylinder engine, individually for each of the cylinders, such that there is a common regularity between a distribution among the cylinders, of a difference of the value of the control parameter of each of the cylinders from the value of the control parameter of a reference cylinder, and a distribution among the cylinders, of a difference of the distance of a narrowed portion of each of the cylinders from the distance of the narrowed portion of a reference cylinder. The control parameter is a parameter that determines an air-fuel ratio of an air-fuel mixture around an ignition plug at a time of ignition in stratified charge combustion operation.

Abstract: When switching the combustion mode from a stoichiometric mode to a homogeneous lean mode, a controller starts switching of the combustion mode after switching of the opening angle of a tumble control valve is started. When a target operating point of an internal combustion engine lies outside a predetermined operational region that is set in a range that excludes at least a low intake load factor region and includes at least a medium intake load factor and medium engine speed region, the controller sets the waiting time from the start of switching of the opening angle of the tumble control valve to the start of switching of the combustion mode to be longer than when the target operating point lies in the predetermined operational region.

Abstract: When the starting timing of a negative valve overlapping (NVO) period exists at the delayed-angle side of the starting timing of a first NVO period, fuel injection into a cylinder is not started; when the starting timing of an NVO period exists between the starting timing of the first NVO period and the starting timing of the second NVO period, fuel injection into the cylinder is started at a given timing that includes the exhaust top dead center; when the starting timing of an NVO period exists between the starting timing of the second NVO period and the starting timing of the third NVO period, fuel injection into the cylinder is started at a given timing that does not include the exhaust top dead center, and that exists at both the advanced-angle and delayed-angle sides of the exhaust top dead center.

Abstract: Methods and systems are provided for improving the detection and mitigation of high speed pre-ignition. In one example, high speed pre-ignition is detected based on concurrent or sequential changes in an integrated knock sensor output in a knock window as well as a pre-ignition window. The high speed pre-ignition is addressed using cylinder fuel deactivation and/or engine load limiting to reduce the risk for run-away pre-ignition.

Abstract: An intake air control device includes: an intake air flow channel that includes an air flow pipe furcated into multiple branch flow channels that communicate with the same combustion chamber; an intake air valve provided to the air flow pipe to adjust an opening degree of the air flow pipe in accordance with a rotation angle thereof; a swirl valve provided to any one of the multiple branch flow channels to adjust an opening degree of the branch flow channel in accordance with a rotation angle thereof; and a cam plate that is rotatable and has a first cam slot. The intake air valve has a first protrusion inserted in the first cam slot. The first cam slot has a first rotation section within which the first protrusion slides and rotates about the rotational shaft of the intake air valve in response to rotation of the cam plate.

Abstract: An electronic control unit sets a misfire determination threshold to a first value in the cylinder injection mode, and sets the misfire determination threshold to a second value smaller than the first value in the port injection mode, and determines that a misfire occurs in the engine when a rotation fluctuation of the engine is larger than the misfire determination threshold. In a case where the cylinder injection mode is changed to the port injection mode, when a predetermined period has elapsed from the change, the electronic control unit changes the misfire determination threshold from the first value to the second value.

Abstract: A piston is used for an engine including: an ignition plug disposed in the vicinity of a central axis of a cylinder; intake and exhaust ports disposed at positions where the ignition plug is interposed therebetween; and an injector disposed at a position offset from the ignition plug toward the intake port to inject fuel sprays toward a crown surface of the piston. The piston includes: a recess formed by recessing the crown surface of the piston with respect to other portions of the crown surface, in which the recess includes a step on an outer peripheral edge over the entire circumference thereof with respect to the other portions, and a pair of lateral sides formed straightly so as to extend substantially in parallel to a straight line connecting the injector and the ignition plug when seen in a direction of the cylinder axis.

Abstract: A controller injects fuel into a cylinder at a high fuel pressure of 30 MPa or higher, at least in a period between a terminal stage of a compression stroke and an initial stage of an expansion stroke when an operating mode of an engine body is at least in a first specified sub-range of a low load range, and at least in a second specified sub-range of a high load range. The controller sets an EGR ratio in the first specified sub-range to be higher than an EGR ratio in the second specified sub-range, and advances start of fuel injection in the first specified sub-range to start of fuel injection in the second specified sub-range.

Abstract: A control system for a spark-ignition internal combustion engine configured to produce tumble flow in a cylinder is provided. The spark-ignition internal combustion engine includes an ignition plug configured to ignite an air-fuel mixture in the cylinder. The control system includes a tumble flow rate controller configured to change a position of a vortex center of the tumble flow as viewed in a direction of a center axis of the cylinder, so as to control a flow rate of the tumble flow around the ignition plug at the ignition timing of the ignition plug.

Abstract: A method to determine the injection pattern in the intake stroke of the combustion cycle of the cylinders of a direct-injection internal combustion engine, which includes determining the overall quantity of fuel to be injected for each combustion cycle of each cylinder during the intake stroke; determining the maximum quantity of fuel to be injected for each partial injection as a function of the value of the start of injection angle, of the speed and of the load of the internal combustion engine; and determining the number of partial injections and the objective quantity to be injected for each partial injection as a function of the quantity of fuel to be injected for each combustion cycle of each cylinder during the intake stroke and of the maximum quantity of fuel to be injected for each partial injection.

Abstract: A method for a turbocharged engine, comprising: during high load conditions, in response to an elevated engine temperature, after port injecting a first quantity of a first gaseous fuel, direct injecting a second quantity of a second, liquid fuel at a first timing that is a function of a desired air-fuel ratio. In this way, engine power may be maximized while simultaneously decreasing the maximum combustion temperature and mitigating engine knock.

Abstract: An engine (10) is a cylinder injection engine, and includes an injector (21) that directly injects a fuel into a combustion chamber (23), and an ignition plug (34) that generates an ignition spark in the combustion chamber (23). An ECU (40) performs multiple first injections to each produce an air-fuel mixture of a lean air-fuel ratio in the combustion chamber (23) before an ignition in one combustion cycle of the engine, and performs a second injection to produce an air-fuel mixture of a rich air-fuel ratio in the combustion chamber (23) before the ignition and after the first injection. In particular, the ECU implements the multiple first injections in such a manner that the first injection implemented early among the multiple first injections produces an air-fuel mixture leaner than that of the first injection implemented subsequently. The ECU implements the second injection only once immediately before an ignition timing.

Abstract: A GDCI engine has a piston arranged within a cylinder to provide a combustion chamber. According to one embodiment, the GDCI engine operates using a method that includes the steps of supplying a hydrocarbon fuel to the combustion chamber with a research octane number in the range of about 30-65. The hydrocarbon fuel is injected in completely stratified, multiple fuel injections before a start of combustion and supplying a naturally aspirated air charge to the combustion chamber.

Abstract: A control apparatus of a premixed charge compression ignition engine that includes an engine body having a cylinder and intake and exhaust passages, and causes a mixture gas to self-ignite inside the cylinder is provided. The apparatus includes a fuel injector for injecting fuel into the cylinder, a water injector for injecting supercritical water or subcritical water into the cylinder, an EGR passage for communicating the exhaust and intake passages and recirculating, as EGR gas, a portion of an exhaust gas discharged from the cylinder to the intake passage, an EGR valve for adjusting an EGR gas recirculation amount, and a controller. The controller includes an engine load determining module for receiving a parameter and determining whether an engine operating state is a first state where the engine load is below a switch load or a second state where the engine load is the switch load or above.

Abstract: In one embodiment, a method of determining correct engine phase in an internal combustion engine without a cam sensor, the engine having a plurality of piston-cylinders that cause rotation of a crankshaft and a fuel delivery assembly associated with each of the plurality of piston-cylinders, the method comprising monitoring an engine parameter, modifying an amount of fuel delivered to a known piston-cylinder, advancing a spark time one of the plurality of piston-cylinders, and determining an actual engine phase based on a change in the engine parameter.

Abstract: Methods and systems are provided for improving engine knock control by accounting for a drop in charge cooling efficiency of a knock control fluid at higher temperatures. In response to the prediction of an elevated temperature of a knock control fluid at a time of release from a direct injector, a pulse width of the injection is adjusted. Any knock relief deficits are compensated for using alternate engine adjustments, such as boost or spark timing adjustments.

Abstract: An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode. Operation of the engine includes determining a combustion pressure parameter for each cylinder. Fueling for each cylinder is controlled responsive to a target state for the combustion pressure parameter for the corresponding cylinder. An end-of-injection timing and a corresponding spark ignition timing for each cylinder are controlled responsive to a target mass-burn-fraction point for an engine operating point.

Abstract: Methods and systems are provided for leveraging engine skip-fire operation during an engine cold-start to expedite catalyst heating. Based on the heat flux required, the engine may be operated with a group of cylinders selectively deactivated, with spark retard on remaining active cylinders increased, and with engine speed increased to reduce NVH issues during the skip-fire operation. The combination of parameters may be adjusted based on changes in exhaust temperature and NVH limits of the engine.

Abstract: A control technique for an engine having a two-step variable valve lift system includes a controller receiving a pressure in an intake manifold of the engine from a manifold absolute pressure (MAP) sensor and a position of an EGR valve of the engine from an exhaust gas recirculation (EGR) sensor. In response to the controller detecting an upcoming HL-to-LL valve state transition, a set of airflow actuators of the engine is controlled, based on the intake manifold pressure and the EGR valve position, to generate a first torque reserve. In response to generating the first torque reserve, the controller then commands the HL-to-LL transition and depletion of the first torque reserve during the HL-to-LL transition to mitigate torque disturbance associated with this transition.

Abstract: A fuel injection control device is adapted for a fuel injection system including an injector and a high-pressure pump that raises pressure of fuel and supplies the fuel to the injector. The fuel injection control device includes a selecting unit for selecting by which one of full lift injection and partial injection to inject fuel, and a pump control unit for controlling operation of the high-pressure pump such that a pressure of fuel supplied to the injector coincides with a target pressure. The selecting unit selects the partial injection when a required injection quantity of fuel is equal to or smaller than a partial maximum injection quantity. A fuel injection system includes the fuel injection control device, the injector, and the high-pressure pump.

Abstract: An oxygen sensor diagnosis control system of a hybrid electric vehicle is provided. The system of a hybrid electric vehicle eliminates an uncertainty of the number of diagnoses of an oxygen sensor and restrains diagnoses of the oxygen sensor in a hybrid electric vehicle. The system of a hybrid electric vehicle includes a hybrid controller operates a vehicle, and determines conversion of an oxygen sensor diagnosis mode based on a result obtained by calculating an oxygen sensor diagnosis index. Additionally, the controller determines whether a condition for diagnosing an oxygen sensor is satisfied when the oxygen sensor diagnosis index decreases to initiate a diagnosis inducing mode or a compulsory diagnosis mode.

Abstract: A compression ignition internal combustion engine includes: a cylinder block and a cylinder head; a piston including a cavity that defines a combustion chamber in cooperation with the cylinder block and the cylinder head; and a nozzle for injecting fuel into the combustion chamber.

Abstract: A method for controlling an engine in various operating modes and for controlling an engine having dual injectors, may include selecting a number of injectors configured to inject fuel based on an operating mode of the various operating modes, and injecting fuel based on a selection of whether to inject fuel while an intake valve is open, or to inject fuel while the intake valve is closed.

Abstract: Methods and systems are provided for leveraging engine skip-fire operation during an engine cold-start to expedite catalyst heating. Based on the heat flux required, the engine may be operated with a group of cylinders selectively deactivated, with spark retard on remaining active cylinders increased, and with engine speed increased to reduce NVH issues during the skip-fire operation. The combination of parameters may be adjusted based on changes in exhaust temperature and NVH limits of the engine.

Abstract: An apparatus includes an engine output module that determines an engine output power parameter for an engine. The apparatus includes an output power threshold module that determines if the engine output power parameter is below an output power threshold. The apparatus includes a NOx module that determines a nitrogen oxide (“NOx”) efficiency of a selective catalytic reduction (“SCR”) system in response to the output power threshold module determining that the determined engine output power parameter is below the output power threshold. The SCR system is in exhaust receiving communication with the engine. The apparatus includes a NOx threshold module that determines if the NOx efficiency is below a NOx efficiency threshold, and a NOx warning module that sends a NOx alarm signal in response to the NOx threshold module determining that the NOx efficiency is below the NOx efficiency threshold.

Abstract: Methods and systems are provided for controlling exhaust emissions by adjusting an injection profile for different fuels injected into an engine cylinder from different fuel injectors during engine start and crank. By splitting fuel injection during start and cranking so that fuel of lower alcohol content is port injected and fuel of higher alcohol content is direct injected as one or multiple injections, the soot load of the engine can be reduced and fuel economy can be improved.

Abstract: A spark-ignition direct injection engine is provided. The engine includes an engine body, a fuel injection valve, a fuel pressure setting mechanism, an ignition plug, and a controller. The controller switches between a compression-ignition mode where the engine body is operated to perform compression-ignition combustion and a spark-ignition mode where the engine body is operated to perform spark-ignition combustion. Immediately after switching from the spark-ignition mode to the compression-ignition mode, the controller operates the engine body in a compression-ignition initial mode where the fuel pressure is set to be 30 MPa or above and the fuel injection valve is controlled to perform the fuel injection in a period from a late stage of the compression stroke to an early stage of the expansion stroke so that the gas mixture self-ignites to combust.

Abstract: An engine control device controls control amounts of a variable valve mechanism and a spark plug, the control amounts in a homogeneous lean operation region set in a first load region are different from that in a non-lean operation region which is a stoichiometric or rich operation region set in a second load region higher than the first load region. The control device performs control, in other operation region set in a third load region between the first and second load region, so that an air-fuel ratio of the internal combustion engine is equal to that of non-lean operation region, the control amount of the variable valve mechanism is equal to that of homogeneous lean operation region and the control amount of the spark plug is equal to that of the non-lean operation region in accordance with an operation amount of an accelerator pedal.

Abstract: The present invention is provided with: an injection timing detection unit; an engine rotation speed detection unit; an engine load detection unit; and a storing unit for storing control data of the variation in optimal ignition timing with respect to engine speed and engine load, and control data of correction coefficient pertaining to optimal ignition timing with respect to the engine load at a specific fuel injection timing. Referring to the control data, the variation in the optimal ignition timing is determined based on the detected fuel injection timing and the detected engine rotation speed; and, referring to the control data, the variation in the optimal ignition timing is determined based on the specific fuel injection timing and the detected engine speed, and the deviation between the respective variation in the optimal injection timing is determined.

Abstract: A control apparatus for an internal combustion engine includes an electronic control unit. The electronic control unit corrects a target air-fuel ratio in an air-fuel ratio control with a first correction value set based on a degree of variation among cylinders in terms of a fuel amount to be injected from the port injector, and a second correction value set based on a degree of variation among the cylinders in terms of a fuel amount to be injected from the in-cylinder injector. A first correction amount of the target air-fuel ratio by the first correction value is set to be larger as an injection amount ratio of the intake-port fuel injection valve is larger, and a second correction amount of the target air-fuel ratio by the second correction value is set to be larger as an injection amount ratio of the in-cylinder fuel injection valve is larger.

Abstract: Methods and systems are provided for performing mitigating actions in response to detecting a fuel injector leak. In one example, a method may include in response to detecting a fuel injector leak, performing first high pressure mitigating actions including increasing a fuel rail pressure, increasing a pulse width delivered to the leaking fuel injector, and commanding fuel injection during compression stroke; in response to the first mitigating actions not reducing the leak below a threshold rate, performing second high pressure mitigating actions including increasing the fuel rail pressure, increasing the pulse width delivered to the leaking injector, and commanding fuel injection during intake stroke for a cylinder receiving fuel from the leaking injector; and in response to the second mitigating actions not reducing the leak below the threshold rate, reducing the fuel rail pressure, and commanding intake stroke fuel injection to all cylinders.

Abstract: Methods and systems are provided for reducing late burn induced cylinder pre-ignition events. Forced entry of residuals from a late burning cylinder into a neighboring cylinder may be detected based on engine block vibrations sensed in a window during an open exhaust valve of the late burning cylinder. In response to the entry of residuals, a pre-ignition mitigating action, such as fuel enrichment or deactivation, is performed in the neighboring cylinder.

Abstract: A method involves controlling a fuel injector to inject a first quantity of a fuel into a cylinder from a plurality of cylinders, of an engine and detecting a first value of a parameter associated with the engine. The method further involves controlling the fuel injector to inject a second quantity of the fuel different from the first quantity of the fuel, into the cylinder of the engine and detecting a second value of the parameter associated with the engine. The method also involves comparing the first value with the second value and detecting a hardware anomaly associated with the engine based on the comparison of the first value with the second value.

Abstract: A control device of a spark-ignition engine is provided. The control device includes a main body of the engine, a fuel injection valve, an ignition plug, and a controller. According to an engine operating state, the controller switches between a compression-ignition mode in which compression-ignition combustion is performed, and a spark-ignition mode in which spark-ignition combustion is performed. The controller switches from the spark-ignition mode to the compression-ignition mode by performing in order, a first stage where an air-fuel ratio of mixture gas is set to a predetermined value and the spark-ignition combustion is performed, a second stage where the air-fuel ratio of the mixture gas is set leaner than the first stage and the compression-ignition combustion is performed, and a third stage where the air-fuel ratio of the mixture gas is set richer than the second stage and the compression-ignition combustion is performed.

Abstract: A fuel-filter malfunction detection device detects a clogging of a fuel filter when specified conditions are satisfied. In a clogging detection, a command discharge quantity to a high-pressure pump is increased more than a total of a fuel injection quantity and a leakage of the fuel supply system while a pressure-reducing valve is closed. When the fuel filter is clogged, a discharge quantity of the high-pressure pump is decreased relative to the command discharge quantity and a differential pressure is generated between an estimated common-rail pressure and an actual common-rail pressure. When an integrated moving average of the averages of the differential pressure is greater than or equal to a specified value, an ECU determines that the fuel filter has a malfunction. Then, a malfunction flag is turned ON.

Abstract: If an engine body is under a load greater than a predetermined load, a controller selects a first fuel feeding mode in which more fuel is fed during a compression stroke than during an intake stroke if the engine body has a temperature equal to or below a predetermined temperature, and selects a second fuel feeding mode in which more fuel is fed during the intake stroke than during the compression stroke if the temperature of the engine body is higher than the predetermined temperature. Immediately after a switch from the first fuel feeding mode to the second fuel feeding mode as the temperature of the engine body rises, the controller sets a correction factor for making an augmenting correction to a fuel amount to be greater than that before the switch.

Abstract: Systems and methods for operating an engine of a vehicle during high engine loads are presented. In one example, fuel may be conserved at higher driver demand torques by limiting engine torque when the engine is operated in an economy mode. Additionally, two accelerator pedal position based fuel enrichment schedules are provided for operating the engine in different operating modes.

Abstract: Methods for controlling vacuum within a brake booster by modifying powertrain operation include determining an intake manifold vacuum in response to actuation of a brake pedal. Increasing the intake manifold vacuum if the brake booster vacuum is less than a desired brake booster vacuum. In some embodiments, the transmission is downshifted to increase engine speed and intake manifold vacuum. In other embodiments, engine torque is reduced to increase intake manifold vacuum and the torque of the electric machine is increased to maintain a constant output torque.

Abstract: An exhaust circulation apparatus that can improve fuel combustion and suppress discharged NOx by expanding an operating region in which homogeneous lean combustion is possible. The exhaust circulation apparatus includes a homogeneous lean combustion unit for performing homogeneous lean combustion in a predetermined lean-burn region, and an EGR apparatus for performing EGR that recirculates a portion of gas that flows through an exhaust system of the internal combustion engine to an intake system. When performing homogeneous lean combustion, the exhaust circulation apparatus controls the EGR apparatus to perform EGR. An LPL-EGR apparatus that recirculates gas flowing through an exhaust passage on a downstream side of a turbine to an intake passage on an upstream side of a compressor is used as the EGR apparatus. Preferably, an air-fuel ratio is controlled so as to be 22:1 and an EGR rate is controlled so as to be between 10% and 20%.

Abstract: A method is disclosed for controlling a concentration of oxygen that is measured by an oxygen sensor of an after-treatment system of an internal combustion engine when a regeneration of an after-treatment device is required. The method may be a computer-implement method. An oxygen sensor target value is lowered in a stepped phase as a function of an exhaust gas flow speed as the exhaust gas passes through the after-treatment system. The oxygen sensor target value is lowered evenly as a function of the exhaust gas flow speed and by a filter phase when a measured air/fuel ratio value is less than or equal to an AFR threshold value and until the oxygen sensor target value is equal to an oxygen sensor final target value. The oxygen concentration is controlled by applying the oxygen sensor target value.

Abstract: A method for diagnosing a failure of a fuel pressure sensor for a high-pressure pump of a GDI engine includes a data collection step of collecting information on a state of a vehicle. A sensor condition determination step determines whether data collected in the data collection step meets conditions for determining the failure of the fuel pressure sensor. A failure determination step determines whether the fuel pressure value of the pressure sensor for the high-pressure pump is greater than or equal to a first reference value, and simultaneously, whether a fuel amount learning value is greater than or equal to a second reference value.

Abstract: A cylinder injection valve that injects fuel inside a cylinder and an intake passage injection valve that injects fuel inside an intake passage are provided. When it is determined that deposit greater than or equal to a predetermined amount accumulates, the fuel is forcibly injected by the cylinder injection valve (deposit removing control). The deposit removing control is performed when a pressure of the fuel supplied to the cylinder injection valve is greater than or equal to a predetermined value and an engine load is relatively high. On the other hand, the deposit removing control is not performed when the pressure of the fuel supplied to the cylinder injection valve is greater than or equal to the predetermined value and the engine load is low.