Methods and systems for estimating engine exhaust gas temperature and adjusting engine operation based on the engine exhaust gas temperature are disclosed. In one example, an offset value for a resistive heating element of an oxygen sensor is determined so that the resistive heating element may be a basis for providing accurate engine exhaust gas temperatures.

A misfire detection device for an internal combustion engine is provided. A mapping takes time series data of instantaneous speed parameters as inputs. Each instantaneous speed parameter corresponds to one of a plurality of successive second intervals in a first interval. The instantaneous speed parameters correspond to the rotational speed of the crankshaft. The first interval is a rotational angular interval of the crankshaft in which compression top dead center occurs. The second interval is smaller than an interval between compression top dead center positions. The mapping outputs a probability that a misfire has occurred in at least one cylinder that reaches compression top dead center in the first interval. The mapping data defining the mapping has been learned by machine learning.

The disclosure relates to a method for ascertaining the flow through a timer valve. The method includes detecting the pressure upstream of the timer valve during an evacuation of a container arranged upstream of the timer valve, ascertaining the flow through the timer valve based on the detected pressure upstream of the timer valve and based on the temperature and the volume of the gas in the container. The method also includes comparing the flow ascertained during the evacuation and a modeled flow and/or comparing a variable dependent on the ascertained flow and a variable dependent on the modeled flow. Additionally, the method includes adapting the model in the event of a discrepancy between the flow ascertained during the evacuation and the modeled flow and/or in the event of a discrepancy between the variable dependent on the ascertained flow and the variable dependent on the modeled flow.

In a current-driving of a fuel injection valve to inject fuel through a single injection or a multi-stage injection, an energization time correction amount is calculated by performing area correction on a current flowing through the fuel injection valve. The single injection is switched to the multi-stage injection when the single injection is consecutively performed under a predetermined condition.

Multiple rotational irregularities in an internal combustion engine are determined. An uneven running value of a currently-ignited combustion chamber in a logical ignition sequence of a plurality of combustion chambers immediately after a logically-preceding ignited combustion chamber is determined. The uneven running value determined for the logically-preceding ignited combustion chamber exceeds a specified threshold value and indicates a fault in the logically-preceding ignited combustion chamber. A compensation factor is determined that. A compensated uneven running value of the currently-ignited combustion chamber from the uneven running value of the currently-ignited combustion chamber and the compensation factor is determined. The compensated uneven running value of the currently-ignited combustion chamber is compared with the specified threshold value to determine whether the currently-ignited combustion chamber has a fault.

A system and an approach for determining various flows in an internal combustion engine, such as an amount of recirculation exhaust gas flow through a controlled valve and a fresh air mass flow to an intake of an engine. Also, among the sensors accommodated in the system, is an inexpensive but slow-responding lambda sensor in the exhaust stream.

A method for determining a combination of an actual intake camshaft phase position of an intake camshaft and an actual exhaust camshaft phase position of an exhaust camshaft of a production internal combustion engine having at least one cylinder, wherein the method is performed in operation of the production internal combustion engine and the relevant actual phase position of the camshafts is determined in relation to an operating point of the production internal combustion engine.

An abnormality diagnosis system is applied to a fuel supply system including a fuel pump that pumps fuel from a fuel tank and a fuel pipe in which fuel discharged from the fuel pump flows. The abnormality diagnosis system stores a minimum fuel pressure in the fuel pipe in one trip after a main switch of the fuel supply system is turned on and until the main switch is turned off and data indicating a state when the minimum fuel pressure was recorded as diagnosis data in a storage device. In the abnormality diagnosis system, an execution device determines a failure spot associated with a decrease in fuel pressure in the fuel pipe using the diagnosis data stored in the storage device and diagnoses an abnormality of the fuel supply system.

A method detects coking in the inlet section of an internal combustion engine with direct fuel injection, a throttle valve and a variable inlet valve lift controller. A correction value calculated by the inlet valve lift controller as an offset value with a preset valve lift is determined. In parallel, a first quantity deviation test is carried out by which a first air ratio value is determined, which is formed from a first lambda value measured during the first quantity deviation test and a desired lambda value of the fuel combustion in the combustion chambers of the internal combustion engine, wherein, in the first quantity deviation test a load control process is carried out by way of the variable inlet valve lift controller. In a second quantity deviation test, a second air ratio value is determined which is formed from a lambda value measured during the second quantity deviation test and a desired lambda value of the fuel combustion. In the second quantity deviation test a load control process is carried out by way of the throttle valve. A comparison value is formed from the first air ratio value and the second air ratio value. Whether coking is present in the inlet section of the internal combustion engine is determined by combined evaluation of the comparison result and of the correction value.

An injection control device of capable of correcting an energization time even in an S/N non-guaranteeable situation includes: an energization controller calculating an energization time correction amount based on an area correction performed by an energization time correction amount calculator regarding electric current flowing in a fuel injection valve when the fuel injection valve is electrically driven for injecting fuel; and an energization instruction time calculator correcting an energization instruction time for fuel injection in a next cycle and thereafter by using the energization instruction time correction amounts in or before a current cycle.