A control apparatus is applied to an internal combustion engine where an EHC and a filter are arranged in this sequence from an upstream side. The control apparatus performs a regeneration process for removing particulate matter deposited in the filter through oxidation, and a recovery process for raising the temperature of exhaust gas to a temperature higher than in the case of the regeneration process and removing the particulate matter deposited at a front end portion of the EHC through oxidation when it is determined that the insulation resistance of the EHC is equal to or lower than a prescribed value. The control apparatus performs the regeneration process and then the recovery process when it is determined that the insulation resistance is equal to or lower than the prescribed value and the deposition amount of the particulate matter in the filter is equal to or larger than a prescribed amount.

A control apparatus of an internal combustion engine having an injector which directly injects fuel into a combustion chamber of a cylinder and a spark plug which ignites an air-fuel mixture containing the fuel injected by the injector includes an air-fuel ratio acquisition unit acquiring an air-fuel ratio of the air-fuel mixture in the combustion chamber, a nitrogen oxide concentration acquisition unit acquiring a concentration of nitrogen oxide in a combustion gas exhausted from the internal combustion engine, and a stratification level estimation unit estimating a level of stratification as a measure of level of distribution of the air-fuel mixture at a predetermined air-fuel ratio or below in a vicinity of the spark plug. The stratification level estimation unit estimates the level of stratification according to the air-fuel ratio acquired by the air-fuel ratio acquisition unit and the concentration of nitrogen oxide acquired by the nitrogen oxide concentration acquisition unit.

A method and system are provided with which it is possible to detect non-firing and untimely firing events in internal combustion and, if necessary, the temperature of the gas in the exhaust gas pipe. This is performed in general by measuring the speed of sound and determining the phase angle between the sender and receiver either arranged on different sides of the exhaust gas pipe or on the same side of the exhaust gas pipe. The receiver, depending on the measurement principle, can include one, two, or in special applications three receivers. Additionally, if necessary, it is possible to suppress the structure-borne sound influence on a speed of sound measurement with low cost and high stability.

A leak detection system for an engine air system is provided. The leak detection system may include a plurality of pressure sensors configured to retrieve pressure data from the engine air system, a plurality of temperature sensors configured to retrieve temperature data from the engine air system, and a controller in communication with each of the pressure sensors and the temperature sensors. The controller may be configured to receive the pressure data and the temperature data, compare the pressure data and the temperature data to one or more predefined data trends, and identify a leak within the engine air system based on the comparison.

The invention concerns a method for controlling a compression release brake mechanism in an combustion engine comprising an air inlet system and an exhaust manifold connected to a turbocharger provided with a variable turbine geometry (VTG) turbine, said exhaust manifold further comprising an exhaust gas recirculation (EGR) channel for recirculation of exhaust gas towards the air inlet system, wherein said turbine is further connected to a back pressure valve (BPV) provided in an exhaust channel, the method comprising determining a desired exhaust manifold gas pressure level on the basis of a measured engine speed and a desired braking torque; continuously monitoring a set of control parameters, including at least two of cylinder pressure, exhaust manifold pressure, turbine speed and turbine expansion ratio; controlling said BPV and said VTG by said control parameters, to drive one of the control parameters to a set maximum level; and controlling the EGR by said control parameters in a closed loop to allow exhaust gas to recirculate towards the air inlet system while driving a second of the set of control parameters to a set maximum level.

Various methods and systems are provided for a multi-fuel capable engine. The system includes a liquid fuel system to deliver liquid fuel to an engine, a gaseous fuel system to deliver gaseous fuel to the engine, and a control system. The control system can control and test the liquid and gaseous fuel systems.

A CPU stops combustion control of Cylinder #1 in order to perform a regeneration process of a GPF and performs a regeneration process of causing an air-fuel ratio of an air-fuel mixture in Cylinders #2 to #4 to be richer. When it is determined that a misfire has occurred because a misfire rate when the regeneration process is not being performed is equal to or greater than a predetermined value, the CPU determines that an internal combustion engine has returned to a normal state based on the premise that the misfire rate when the regeneration process is not being performed decreases.

A turbocharger system (1) of a combustion engine (4) comprises a turbocharger turbine (5) operable by exhaust gases, a valve (7) configured to control gas flow of pressurized gas from a pressurized gas reservoir (6) to the turbocharger turbine (5), and a sensor (8). Turbocharger system operation comprises injecting a test pulse of pressurized gas from the pressurized gas reservoir (6) to drive the turbocharger turbine (5) by means of controlling the valve (7), detecting an impact of injected pressurized gas on the turbocharger turbine (5) by means of the sensor (8), collecting data from the sensor (8), and diagnosing the turbocharger system (1) by evaluating an operational response of the turbocharger turbine (5) as a result of the injected test pulse of pressurized gas, based on the collected data.

Methods and systems using model based and iterative calculations of mass flow throughout an internal combustion engine system. A secondary air injection valve is provided to selectively allow intake air to pass to the exhaust side of the engine system to aid in exothermic reaction with exhaust gasses exiting the engine for various purposes. The iterative calculations of mass flow include estimation of the mass flow through the secondary air injection valve.

Systems and methods for operating an engine that includes an exhaust system with a carbonaceous soot trap described. In one example, a carbonaceous soot load estimate for the carbonaceous soot trap is performed when a differential pressure sensor is degraded. The carbonaceous soot estimate may be performed when the engine is not rotating.