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.

To provide a sensor control device capable of identifying a short circuit terminal with a simple configuration and whose identification operation is not easily affected by environmental conditions around the sensor. The sensor control device includes a short circuit detection unit that detects a short circuit of a sensor having a plurality of terminals, a resistance value control unit that increases a resistance value of an element between the terminals when the short circuit of the sensor is detected by the short circuit detection unit, and a short circuit terminal identification unit that identifies at which of the plurality of terminals a short circuit occurs when the resistance value control unit increases the resistance value of the element between the terminals to a set value or greater.

A method detects a fault, in particular coking, in the intake tract of an internal combustion engine with direct fuel injection, a throttle valve, and a variable intake valve lift controller. The method has the steps of a) carrying out a first quantity deviation test, by which a first air ratio value is ascertained that is formed from a lambda value, which is measured during the first quantity deviation test, and a desired lambda value of the fuel combustion in the fuel chambers of the internal combustion engine, wherein in the first quantity deviation test, a load control is carried out by the variable intake valve lift controller; b) carrying out a second quantity deviation test, by which a second air ratio value is ascertained that is formed from a lambda value, which is measured during the second quantity deviation test, and a desired lambda value of the fuel combustion in the fuel chambers of the internal combustion engine, wherein in the second quantity deviation test, a load control is carried out by the throttle valve; and lastly c) determining a comparison result from the first air ratio value and the second air ratio value, the presence of a fault in the intake tract of the internal combustion engine being detectable using the comparison result.

An evaluation and control unit, designed as an ASIC, for operating a broadband lambda sensor that includes at least one electrical line. The evaluation and control unit includes at least one electrical terminal for electrically connecting to the electrical line of the broadband lambda sensor, and a device for determining a setpoint value of a current flowing into the electrical terminal and for comparing this setpoint value with the current actually flowing into the electrical terminal and for comparing with the aid of comparators the electrical potential being applied to the electrical terminal with predefined limits.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

A method for estimating the ageing of an exhaust gas sensor (16) placed in an exhaust line (14) of a diesel internal combustion engine (10) of an industrial vehicle (1) includes: —acquiring (S100) an initial value of an estimated remaining lifetime (50) of the exhaust gas sensor; —measuring (S102) the time spent by the engine in each of several predefined engine operation modes during a predefined time period; —for each of the engine operation modes, calculating (S104) a lifetime loss value depending on the time spent by the engine in said engine operation mode during the predefined time period and on a predefined ageing rate associated to said engine operation mode; —updating (S106) the estimated remaining lifetime value by subtracting each calculated lifetime loss value from the initial value.

The invention relates to an internal combustion engine with an air intake system and an exhaust system is embodied as an internal combustion engine, in particular a gasoline engine, that is charged by means of an exhaust gas turbocharger. At least one three-way catalytic converter is arranged in the exhaust system of the internal combustion engine. Furthermore, a low-pressure exhaust gas recirculation system is provided that connects the exhaust system downstream from a turbine of the exhaust gas turbocharger and upstream from the at least one three-way catalytic converter to the air intake system upstream from a compressor of the exhaust gas turbocharger. The invention further relates to a method for exhaust aftertreatment of such an internal combustion engine.

A method for operating an internal-combustion engine having an exhaust gas catalyst, a first exhaust gas sensor upstream of the exhaust gas catalyst and a second exhaust gas sensor downstream of the exhaust gas catalyst. A fill level of an exhaust gas component that can be stored in the exhaust gas catalyst is determined using a theoretical catalyst model, into which, as the input value, a signal of the first exhaust gas sensor (a first signal); a signal of the second exhaust gas sensor (a second signal); and a target signal are provided. The target signal corresponds to the signal that would be expected at the determined fill level in the exhaust gas catalyst. The catalyst model is reinitiated when the deviation of the second signal from the target signal exceeds a predetermined threshold value. The fill level is also regulated, and an air-fuel mixture is adjusted.

Methods and systems are provided for detection of cylinder misfire in an engine. In one example, a system may comprise a first cylinder and second cylinder of the engine having exhaust flows combined together in an exhaust system before being combined with other cylinders of the engine. The first cylinder and second cylinder may share an exhaust gas sensor mounted in the exhaust in a position to sense exhaust from the first cylinder and second cylinder, and being positioned before exhaust from other cylinders is combined with sensed exhaust from the first cylinder and second cylinder. The system may further include a control system with instructions stored therein to indicate detected misfire in one or more of the first and second sensors based on an output from the exhaust gas sensor.

Methods and systems are provided for adapting a target impedance of an oxygen sensor. In one example, a method may include updating a target impedance of an oxygen sensor based on a difference between an estimated voltage across a sensing element of the oxygen sensor and a reference RMS voltage of the sensing element. The temperature of the oxygen sensor may be adjusted based on the updated target impedance.