A control apparatus for the internal combustion engine has a multicore processor mounted with a plurality of the cores, calculates various tasks regarding an operation of the internal combustion engine, and distributes the tasks to the plurality of the cores respectively to perform a calculation, and a controller that makes the number of cores for use in the calculation smaller while fuel cutoff is carried out than before the fuel cutoff is carried out. The controller selects, as a designated core, at least one of the cores for use in a specific calculation associated with combustion of the internal combustion engine. The controller stops the designated core from being used while fuel cutoff is carried out. As the specific calculation associated with combustion, for example, it is possible to mention a combustion forecasting calculation of a cylinder model, a temperature forecasting calculation of a catalyst temperature estimation model, and a fuel adhesion amount forecasting calculation of a fuel adhesion model.

An internal combustion engine comprises an exhaust purification catalyst arranged in an exhaust passage of the internal combustion engine and being able to store oxygen in inflowing exhaust gas and an air-fuel ratio sensor arranged at a downstream side of the exhaust purification catalyst in a direction of exhaust flow and detecting an air-fuel ratio of exhaust gas flowing out from the exhaust purification catalyst and stops or decreases a feed of fuel to a combustion chamber as fuel cut control. The abnormality diagnosis system calculates a characteristic of change of an air-fuel ratio based on an output air-fuel ratio output from the air-fuel ratio sensor at the time when the output air-fuel ratio first passes a part of an air-fuel ratio region of a stoichiometric air-fuel ratio or more after an end of the fuel cut control, and diagnoses abnormality of the air-fuel ratio sensor based on the characteristic of change of the air-fuel ratio. As a result, the diagnosis system can diagnose the abnormality of deterioration of response of the downstream side air-fuel ratio sensor when necessary without fail when performing fuel cut control.

A system according to the principles of the present disclosure includes a storage capability module and at least one of an engine speed control module and a spark control module. The storage capability module determines a capability of a catalytic converter to store oxygen. The engine speed control module controls a speed of an engine based on the oxygen storage capability of the catalytic converter. The spark control module controls a spark timing of the engine based on the oxygen storage capability of the catalytic converter.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

A learning method for controlling opening or closing of an intake/exhaust valve of a vehicle may include a state determining step determining whether a vehicle state satisfies a learning entry condition, a learning frequency determining step determining whether a learning frequency is less than a preset reference frequency after the vehicle starts, when the vehicle state satisfies the learning entry condition, a change learning step learning an area of an inflow passage of the intake/exhaust valve that is changed due to a deposition of impurities, when the learning frequency while driving is less than the preset reference frequency after the vehicle starts, and an escape condition determining step determining whether the vehicle state satisfies a learning escape condition, after the learning step.

Various methods and arrangements for improving fuel economy in decel fuel cut-off (DFCO) operation of an internal combustion engine are described. In one aspect, a catalytic converter bypass valve diverts the pumped air in DFCO mode from flowing through a catalytic converter. The diverted, pumped air may flow through a bypass line or be returned to the engine intake manifold through an exhaust gas recirculation return line. Another aspect of the invention relates to directing the diverted pumped air through an emission control device.

An apparatus and method for controlling a fuel injection system of an internal combustion engine is disclosed. Each fuel injector in the system is operated to perform a predetermined injection pattern per engine cycle. A signal representative of a fuel pressure within the fuel rail during the operation of the fuel injectors is sampled. A Fourier analysis of the fuel rail pressure signal is performed to determine one or more harmonic components thereof. The determined harmonic components of the fuel rail pressure signal are used to calculate a dynamic fuel quantity that flows through a fuel injector during an injection pulse of the injection pattern. A fuel quantity actually injected by the fuel injector during the injection pulse as a function of the dynamic fuel quantity is calculated.

A method is provided for avoiding incorrect combustion misfire fault detection in an internal combustion engine in a motor vehicle with a dual mass flywheel. In order to detect combustion misfiring, a characteristic variable, which is dependent on the acceleration of the internal combustion engine, is determined continuously during the ongoing operation of the internal combustion engine and compared with a predefined irregular running threshold value. When the irregular running threshold value is exceeded, a combustion misfire is detected, wherein the frequency of detected combustion misfiring, for example at a specific number of crank shaft revolutions, is detected. When a defined frequency threshold is exceeded, a combustion misfire fault detection is activated. When a dual mass flywheel bounce is detected with the simultaneous detection of combustion misfiring, the injection of at least one cylinder is reduced or switched off for a predefined frequency or for a predefined time.

An internal combustion engine includes a port injector that injects fuel into an intake port and a direct injection injector that injects fuel directly into a combustion chamber. When the internal combustion engine is in a low load condition while requiring fuel injection, a controller stops fuel injection through the port injector so that an entire required fuel injection amount is injected through the direct injection injector. As a result of this processing, the fuel pressure of the direct injection injector is reduced quickly in the low load condition.

Methods and systems are provided for monitoring and adapting sensors and actuators in the induction system and exhaust system of an internal combustion engine during a period of time in which fresh air is flowing through the internal combustion engine without fuel delivery. According to the disclosure, the period of time in which fresh air is flowing through the internal combustion engine when fuel delivery is turned off and the monitoring and adapting is being carried out is extended by transferring torque produced by electric motor to the internal combustion engine.