A system and method for controlling an exhaust gas recirculation (EGR) system in a hybrid vehicle using an intrusive monitor include adjusting EGR flow through an EGR valve based on an average pressure difference between pressure measured from a manifold absolute pressure (MAP) sensor and inferred pressure determined from mass air flow (MAF) into an intake of an engine when engine speed, throttle and camshaft timing position change is below a corresponding threshold. The measured pressure and inferred pressure are determined when the EGR valve is in a closed position and an open position.

A controller for a motor vehicle having an internal combustion engine, and a device for detecting a fire in a fluid conduit, the device having a fluid state sensor for detecting a state variable of a fluid that is conducted in the fluid conduit, are provided. The determination of a fire situation is performed in a manner dependent on a signal of the fluid state sensor.

Proposed is a method and system for controlling an Exhaust Gas Recirculation (EGR) device in high-load driving, and an internal combustion engine vehicle including the system. The method of controlling an EGR device in high-load driving compares a ratio of pressures at a front end and a rear end of a throttle valve with a preset critical value that is a reference for determining high-load driving, performs Wide Open Throttle (WOT) control for fully opening the throttle valve when the ratio of pressures is larger than the preset critical value, determines whether engine torque due to the WOT control and use of EGR satisfies torque requested by a driver, and corrects throttle opening or stops use of EGR, depending on whether the engine torque due to use of EGR together with the WOT control satisfies the requested torque.

Proposed is a method and system for controlling an Exhaust Gas Recirculation (EGR) device in high-load driving, and an internal combustion engine vehicle including the system. The method of controlling an EGR device in high-load driving compares a ratio of pressures at a front end and a rear end of a throttle valve with a preset critical value that is a reference for determining high-load driving, performs Wide Open Throttle (WOT) control for fully opening the throttle valve when the ratio of pressures is larger than the preset critical value, determines whether engine torque due to the WOT control and use of EGR satisfies torque requested by a driver, and corrects throttle opening or stops use of EGR, depending on whether the engine torque due to use of EGR together with the WOT control satisfies the requested torque.

An internal combustion engine having intake and exhaust manifolds, a turbocharger with a compressor, and at least one of: an exhaust gas recirculation (EGR) valve and a variable geometry turbine (VGT). The system further includes a control computer configured to determine at least one of torque demand, pressure across the compressor, and pressure gradient ratio between the exhaust manifold and the intake manifold relative to one of exhaust manifold pressure, intake manifold pressure, and 1. The control computer performs at least one of: closing the EGR valve in response to the determined at least one of torque demand, pressure across the compressor, and pressure gradient ratio, and lessening restriction provided by the variable geometry turbine responsive to the determined at least one of torque demand, pressure across the compressor, and pressure gradient between the exhaust manifold and the intake manifold.

An upper-limit threshold value and a lower-limit threshold value of a fore-and-aft differential pressure of an EGR control valve is calculated based on an intake-air quantity detected by an airflow meter. An actual fore-and-aft differential pressure of the EGR control valve is calculated from detected values of an upstream-side pressure sensor and a downstream-side pressure sensor. Then, these threshold values are compared with the actual fore-and-aft differential pressure, and when the actual fore-and-aft differential pressure exceeds the upper-limit threshold value or when the actual fore-and-aft differential pressure is less than the lower-limit threshold value, it is determined that the pressure loss of an intake and exhaust system has changed. If it is determined that the pressure loss of an intake and exhaust system has changed, EGR is inhibited, and if not so, EGR is permitted to be performed. These threshold values are varied depending on a target EGR rate.

A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

This engine includes an EGR device. The engine is provided with: an EGR gas temperature sensor; an EGR valve; an EGR control unit; an EGR valve position detection unit; a diagnosis unit; a first timer; a second timer; and a diagnosis control unit. The diagnosis unit diagnoses whether the EGR gas temperature sensor has failed, on the basis of a detected value from the EGR gas temperature sensor. The first timer, when the EGR valve is open, performs counting in accordance with the passage of time. The second timer, if a count value of the first timer is greater than or equal to a first threshold value set in advance, and if a predetermined condition is satisfied, performs counting in accordance with the passage of time. The diagnosis control unit prohibits diagnosis by the diagnosis unit if a count value of the second timer is less than a second threshold value set in advance, and permits the diagnosis if the count value is greater than or equal to the second threshold value.

This engine includes an EGR device. The engine is provided with: an EGR gas temperature sensor; an EGR valve; an EGR control unit; an EGR valve position detection unit; a diagnosis unit; a first timer; a second timer; and a diagnosis control unit. The diagnosis unit diagnoses whether the EGR gas temperature sensor has failed, on the basis of a detected value from the EGR gas temperature sensor. The first timer, when the EGR valve is open, performs counting in accordance with the passage of time. The second timer, if a count value of the first timer is greater than or equal to a first threshold value set in advance, and if a predetermined condition is satisfied, performs counting in accordance with the passage of time. The diagnosis control unit prohibits diagnosis by the diagnosis unit if a count value of the second timer is less than a second threshold value set in advance, and permits the diagnosis if the count value is greater than or equal to the second threshold value.

A method of determining an operational status of an exhaust gas recirculation valve of an internal combustion engine arrangement, the EGR valve being configured to control a flow of combusted exhaust gas from an exhaust manifold to an inlet manifold of the ICE arrangement. The method comprising controlling the EGR valve to transition from a closed position; obtaining a signal indicative of a variation of temperature level of the gas present in the inlet manifold at a duration between a first point in time and a second point in time when the EGR valve assumes the open position; determining, based on the signal indicative of the variation of the temperature level, a velocity value indicative of a maximum increase in change of temperature level during the time period between the first point in time and the second point in time; comparing the velocity value with a predetermined threshold; and determining that the EGR valve is operational when the velocity value is higher than the predetermined threshold.