Methods and systems are provided for providing passive boost pressure monitoring for slow response with higher confidence. A response time of a boost pressure feedback control loop following a boost pressure deviation that is triggered by either system disturbances or operator torque demand is monitored. Slow boost behavior is correlated with boost control degradation affecting drivability and emissions.

Various embodiments may include a method for checking the plausibility of the functionality of a crankcase ventilation system of an internal combustion engine, wherein crankcase ventilation system has a crankcase, an intake tract equipped with an intake manifold, and a connecting line arranged between the crankcase and the intake manifold, the method comprising: detecting an occurrence of a negative load change; in response, comparing a measured intake manifold pressure with a modelled intake manifold pressure using acquired operating variables of the internal combustion engine and of a crankcase model; and determining on the basis of the comparison result whether the connecting line arranged between the crankcase and the intake manifold becomes blocked or drops out.

A method of detecting a defeat device includes: determining turbo operation when a turbocharger of a vehicle is operated; determining flow rate of the air to be applied to an intake manifold wherein it is determined whether which flow rate out of a first flow rate of the air passing through a throttle valve and a second flow rate of the air measured by a hot-film air mass flow (HFM) sensor is used as the flow rate of the intake manifold; determining whether pressure in the intake manifold is in a normal range based on the flow rate of the intake manifold; and determining that the defeat device is installed if it is determined that the pressure in the intake manifold is not in the normal range and storing information of the defeat device.

A method for determining a desired intake manifold pressure of an internal combustion engine by means of an iterative method, wherein a cylinder charge is determined for an intake manifold pressure iterated during the iterative method, and the desired intake manifold pressure is determined as a function of the cylinder air charge that has been determined. In addition, a control device for carrying out the method is provided.

An operating method for a fresh-air feed device for an internal combustion engine is configured for feeding fresh air from the environment surrounding the internal combustion engine into at least one combustion chamber of the internal combustion engine. A controllable throttle valve is configured for varying a through-flowable area of the fresh-air feed device and for at least partially shutting off the fresh-air feed device. The device has a compressor which is arranged upstream of the throttle valve in an intended through-flow direction from the environment into the combustion chamber, which is configured for conveying an air mass flow in the intended through-flow direction in the fresh-air feed device. A pre-compressor section of the device is arranged upstream of the compressor, an intermediate section is arranged downstream of the compressor device and upstream of the throttle valve, and a post-throttle section is arranged downstream of the throttle valve. A first air pressure sensor is arranged in the pre-compressor section, and a second air pressure sensor is arranged in the post-throttle section. In a first operating state, a first air pressure is measured via the first air pressure sensor. In a second step in the first operating state, a second air pressure is measured via the second air pressure sensor. Based on the second air pressure, a theoretical air pressure for the intermediate section is ascertained in a manner dependent on a theoretically through-flowable area set by the throttle valve. The theoretical air pressure is compared with the first air pressure or with a comparison value for the first air pressure. In the event of a deviation of the theoretical air pressure from the first air pressure or from the comparison value beyond an error threshold value, a corrective value for the ascertainment of the theoretical air pressure is determined.

Various embodiments may include a method for operating an internal combustion engine having a wastegate turbocharger comprising: measuring an intake pipe pressure; determining a cylinder air mass from the pressure; injecting an amount of fuel into a cylinder of the internal combustion engine based on the air mass; determining and a plausible intake pipe pressure gradient for a current engine operating point; calculating a gradient of the measured intake pipe pressure during a full-load acceleration; comparing the stored plausible intake pipe pressure gradient to the calculated gradient; identifying manipulation of the intake pipe pressure sensor if the difference between the stored plausible intake pipe pressure gradient and the calculated gradient exceeds a selected threshold value; and limiting a power output of the engine if manipulation is identified.

An engine diagnostic system includes a control system having a controller operatively connected to an engine. A monitoring system has a sensor operatively connected to the engine. A diagnostic system is operatively connected to the engine. The diagnostic system is configured to implement a sensor diagnostic procedure that includes a sensor health test. The sensor health test includes comparing a measured value of a sensor to an expected value and determining the health of the sensor based on the difference between the measured value and the expected value. The sensor diagnostic procedure can also include telematics data analysis.

A controller for an internal combustion engine includes a processing circuit configured to execute a calculating process that calculates a returned air amount and an operating process that operates a fuel injection valve so that an air-fuel ratio of a mixture that is burned in a combustion chamber is controlled to a target value. The operating process includes under a condition in which the returned air amount is increased, having the fuel injection valve inject fuel increased in amount from a constant fuel amount, which is an amount of fuel injected when the returned air amount is unchanged, and under a condition in which the returned air amount is decreased, having the fuel injection valve inject fuel decreased in amount from the constant fuel amount.

An EGR apparatus includes an EGR passage to allow part of exhaust gas discharged from an engine to an exhaust passage to flow as EGR gas into an intake passage; an EGR valve to regulate an EGR flow rate in the EGR passage; various sensors for detecting an engine running state; and an ECU to control the EGR valve based on the detected running state to diagnose abnormality in the EGR valve. The ECU calculates a reference intake pressure according the detected engine rotation speed and load by reference to a reference intake pressure map showing a relationship of the reference intake pressure to engine rotation speed, and engine load, and determine whether or not the EGR valve has abnormality in opening/closing by comparing the reference intake pressure with the detected intake pressure.

Methods, devices, estimators, controllers and algorithms are described for estimating working chamber air charge during engine operations. The described approaches and devices are well suited for use in dynamic firing level modulation controlled engines. Manifold pressure is estimated for a time corresponding to an induction event associated with a selected working cycle. The manifold pressure estimate accounts for impacts from one or more intervening potential induction events that will occur between the time that the manifold pressure is estimated and the time that the induction event associated with the selected working cycle occurs. The estimated manifold pressure is used in the estimation of the air charge for the selected working cycle. The described approach may be used to individually calculate the air charge for each induction event at any time that the engine is operating in a mode that can benefit from the individual cylinder air charge estimations.