Abstract: Methods and systems for evaluating robustness of vehicle diagnostics and monitoring. One system includes a memory, a communication interface, and an electronic processor. The electronic processor is configured to access diagnostic event data of a vehicle system. The electronic processor is also configured to determine a RQ variable for the current operation cycle based on a set of maximum debounce levels included in the diagnostic event data and a failure threshold. The electronic processor is also configured to store, in the memory, the RQ variable as RQ data at an end of the current operation cycle. The electronic processor is also configured to transmit, via the communication interface, the RQ data for an external robustness evaluation. The electronic processor is also configured to receive, via the communication interface, an update to the failure threshold based on the external robustness evaluation.

Abstract: When a temperature increasing process is performed, a CPU sets a target temperature of a catalyst to be lower when a coolant temperature is low than when the coolant temperature is high. The CPU decreases an increase coefficient of fuel in the temperature increasing process when a value obtained by subtracting an estimated value of a temperature of the catalyst from the target temperature is equal to or less than a first prescribed value.

Abstract: The present invention discloses is a method for collecting a temperature of a heating pipeline, the method comprising: collecting a circuit signal of a heating resistor; calculating a current resistance value of the heating resistor according to the circuit signal; and calculating a current temperature of the heating pipeline according to the current resistance value. By using the method for collecting the temperature of the heating pipeline, measurement of the temperature of the heating pipeline can be realized by directly measuring the resistance value of the heating resistor in the heating pipeline, which may avoid the use of an additional temperature sensor, thereby reducing the number of connecting wires or other accessories.

Abstract: A method of detecting a valve opening or closing event in a solenoid operated reductant injector valve includes applying a voltage to the solenoid to actuate the valve, the voltage having a chopped waveform. A resultant current through the solenoid is sampled at local maxima and minima. Values of a difference between the local maxima and subsequent local minima or between local minima and subsequent local maxima are determined. A rate of change of the difference values are determined and a valve opening or closing event based on the rate of change is determined.

Abstract: A sensor system for an engine for which an automatic stop-restart control is performed, the sensor system including: an exhaust gas sensor including a heater that heats a sensor element; and a control unit configured to: while the engine is stopped by the automatic stop-restart control, execute a preheat control of adjusting a temperature of the sensor element to a preheat temperature lower than an activation temperature; when an automatic start condition is satisfied, stop the preheat control and increase the temperature of the sensor element to the activation temperature; when an automatic stop condition is satisfied and a delay condition has not been satisfied, set the preheat temperature to a first temperature; and when the automatic stop condition is satisfied and the delay condition has been satisfied, set the preheat temperature to a second temperature higher than the first temperature.

Abstract: A control apparatus for an internal combustion engine includes an exhaust gas sensor that has a sensor element and a heater for electrically heating the sensor element, a sensor circuit that detects the electric current generated by the exhaust gas sensor, a controller configured to: carry out starting processing to start the internal combustion engine, learn a value of the output of the sensor circuit when the starting processing is carried out by the controller, and control a temperature of the sensor element by using the heater, and controls the temperature of the sensor element to less than the predetermined temperature until the learning of the output value of the sensor circuit by the controller is completed after the starting processing is carried out by the controller.

Abstract: Methods and systems are provided for an oxygen sensor heater. In one example, a method may include applying a less than maximum duty cycle of voltage to the oxygen sensor heater during an engine cold start (e.g., when a temperature of the oxygen sensor is less than its light-off temperature) and adjusting the applied duty cycle of voltage to maintain a constant amount of power. In this way, the oxygen sensor may be heated at a constant rate even as a resistance of the oxygen sensor heater increases, decreasing an amount of time before the oxygen sensor reaches its light-off temperature.

Abstract: A gas detection device includes a temperature control part configured to detect an element impedance by applying a high frequency voltage to an element part, and to control an electric power to be supplied to a heating part based on the detected element impedance. The temperature control part is configured, when the applied voltage control for SOx detection is being performed and at least a voltage decrease sweep is being performed, to perform a second element temperature control to stop detecting the element impedance to set the electric power to be supplied to the heating part to a predetermined electric power.

Abstract: An electric device capable of suppressing an influence of variation of a consumed current on a superimposed signal is provided. An electric device which transmits a superimposed signal obtained by superimposing a data signal on the operation signal according to a state of an operating element to the outside, includes a current consuming part configured to consume a current, and a current control part configured to control current consumption in a circuit including the current consuming part such that current variation of the superimposed signal following variation of the consumed current in the current consuming part is suppressed.

Abstract: A process of forming an epitaxial substrate is disclosed, where the epitaxial substrate includes a nucleus forming layer made of aluminum nitride (AlN) grown on a substrate made of silicon carbide (SiC). The process includes steps of: (1) first measuring the first reflectivity R0 of a surface of the SiC substrate, (2) growing the nucleus forming layer made of AlN as measuring second reflectivity R1 of a grown surface of the AlN nucleus forming layer, and (3) ending the growth of the AlN nucleus forming layer when a ratio R1/R0 of the reflectivity enters a preset range.

Abstract: Disclosed are methods, systems, and computer-readable mediums for determining the composition of gaseous fuel. An initial gaseous fuel stream is provided that includes methane, non-methane hydrocarbons, and inert gases. Air is mixed into the initial fuel stream upstream of a first catalyst. The first catalyst oxidizes only the non-methane hydrocarbons of the initial fuel stream to produce a resultant fuel stream comprising methane and inert gases. Air is mixed into the resultant fuel stream downstream of the first catalyst and upstream of a second catalyst. The second catalyst oxidizes only the methane hydrocarbons of the resultant fuel stream to produce an output fuel stream. Mole ratios of the methane, the non-methane hydrocarbons, and the inert gases of the initial fuel stream are each determined.

Abstract: Methods and systems are provided for accurately inferring an exhaust temperature during steady-state and transient vehicle operation based on the duty cycle of an exhaust gas sensor heating element. A steady-state temperature is inferred based on an inverse of the duty cycle, and then adjusted with a transfer function that compensates for transients resulting from changes in vehicle speed, and load, and for the occurrence of tip-in and tip-out events. The inferred temperature can also be compared to a modeled temperature to identify exhaust temperature overheating conditions, so that mitigating actions can be promptly performed.

Abstract: A preheating control for controlling an energization of a heater is executed so that a sensor element of an exhaust gas sensor is preheated within a temperature range in which no element crack caused by water occurs until a predetermined preheating period elapses after an engine starts. In performing the preheating control, first, an energization duty of the heater is set to a preheating promotion energization duty to promptly raise a temperature of the sensor element until it is determined that the temperature of the sensor element reaches a predetermined upper limit temperature. After it is determined that the temperature of the sensor element reaches the upper limit temperature, the energization duty of the heater is set so that the temperature of the sensor element is maintained at the upper limit temperature to sufficiently raise the temperature of the overall sensor element during the preheating control.

Abstract: A method for diagnosing the function of an exhaust gas sensor in an exhaust gas. The function is evaluated here according to whether during a heating phase an operating temperature of the exhaust gas sensor has been reached for a predefined time period. It is taken into account here whether during the heating phase sufficient heating power has been available to carry out a successful heating phase.

Abstract: A multi voltage sensor system includes one or more charge pumps, a sensor bridge and readout circuitry. The one or more charge pumps are configured to provide a high voltage. The sensor bridge is biased by the high voltage and is configured to provide sensor values. The readout circuitry includes only low voltage components. The readout circuitry is configured to receive the sensor values.

Abstract: A direct fuel injection internal combustion engine fluidly coupled to an exhaust aftertreatment system is described and includes a plurality of fluidly coupled exhaust purifying devices and an exhaust gas sensor. A method of controlling the engine includes, activating, via a heater controller, a heating element of the exhaust gas sensor in response to starting the internal combustion engine. An exhaust gas feedstream is monitored to determine a temperature of the exhaust gas sensor. Engine control to effect heating of one of the exhaust purifying devices is permitted only when a temperature of the exhaust gas sensor is greater than a threshold temperature.

Abstract: Methods and systems are provided for reducing blackening of an oxygen sensor due to voltage excursions into an over-potential region. Before transitioning the sensor from a lower voltage to an upper voltage during variable voltage operation, an operating temperature of the sensor is reduced via adjustments to a sensor heater setting. The reduction in temperature increases the range of temperatures available to the sensor before the over-potential region is entered.

Abstract: Methods and systems are provided for reducing soot sensor electrode degradation in harsh chemical environment introduced as a result of desulfation of a lean NOx trap positioned upstream of the soot sensor. In one example, a method may include in response to the SOx load being higher than the threshold, prior to initiating desulfation of LNT, operating the soot sensor in a pre-desulfation mode where the negative electrode is connected to the positive electrode for a brief duration, while the positive electrode is disconnected from the positive electrode. However during desulfation, when H2S is released as a by-product, both the electrodes may be open, i.e. not connected to the positive electrode or ground, thereby reducing the possibility of sensor degradation.

Abstract: Methods and systems are provided for adjusting heater power of an oxygen sensor. In one example, a method for an engine includes adjusting heater power of a heating element of the oxygen sensor when the heater power increases by a threshold amount. The method includes subsequently increasing heater power back to a baseline power level responsive to a temperature of the heating element.

Abstract: A control device for an internal combustion engine includes: an EGR control unit executing open/close control over an EGR valve on the basis of an operating state of the engine; and a fuel injection control unit carrying out at least one of port injection and in-cylinder direct injection by operating at least one of a port injection injector and an in-cylinder direct injection injector on the basis of the engine operating state. The fuel injection control unit sets an EGR non-operation in-cylinder direct injection region, in which the port injection is stopped and the in-cylinder direct injection is carried out while the EGR valve is closed, within an operation range of the engine, and sets part of an EGR operation port injection permissible region, in which at least the port injection is carried out while the EGR valve is open, within the EGR non-operation in-cylinder direct injection region.

Abstract: A gas sensor control apparatus (1) includes a gas sensor (8) having an oxygen pump cell (14); a sensor drive circuit (52) which energizes the gas sensor; terminal voltage output means (54) which detects and outputs a terminal voltage of the oxygen pump cell; anomaly detection means (58) which compares the terminal voltage and a first threshold value, and when the terminal voltage exceeds the first threshold value, outputs a short circuit anomaly signal informing of a short circuit; a controller (55) which compares the terminal voltage and a second threshold value less than the first threshold value, and when the terminal voltage exceeds the second threshold value, generates a cell voltage anomaly signal informing of an application of an overvoltage to the oxygen pump cell; and command means (9) which, when receiving the short circuit anomaly signal or cell voltage anomaly signal, outputs a de-energization command.

Abstract: The present invention provides an abnormality diagnosis apparatus for an exhaust gas purification apparatus having an SCR catalyst, with which a misdiagnosis of an abnormality in the SCR catalyst even though the SCR catalyst is normal can be suppressed. In the present invention, a NOx purification ratio is determined using an estimated NOx inflow amount as a parameter, and an abnormality in the SCR catalyst is diagnosed on the basis of the NOx purification ratio. According to the present invention, a minimum NH3 adsorption amount is determined as an NH3 adsorption amount of the SCR catalyst in a condition where an actual NOx inflow amount reaches a maximum. When the minimum NH3 adsorption amount equals or exceeds a predetermined amount, a determination is made as to whether or not a NOx purification ability of the SCR catalyst has deteriorated from a normal condition by comparing the NOx purification ratio with a first threshold.

Abstract: A gas sensor control apparatus (1) for controlling a gas sensor (2) includes a change amount detection means (40); an element resistance detection means for detecting the element resistance Rpvs of a sensor element section (3) on the basis of the response change amount ?Vs; a heater energization control section for on-off controlling the supply of electric current to a heater section (4) by pluses PS having a fixed period T; and an instruction signal output section for instructing the change amount detection section (40) to detect the response change amount ?Vs at a third timing t3 which comes after elapse of a predetermined wait time TW from a second timing t2 (heater energization off) which changes in accordance with the pulse width PSW.

Abstract: If an amount of fuel is not increased and a direct injection air-fuel ratio learning has not been completed, fuel injection from a port fuel injection valve is stopped without executing EGR, fuel injection control is executed such that the fuel injection occurs only from an in-cylinder fuel injection valve, and the direct injection air-fuel ratio learning is executed. If the amount of the fuel is increased, the fuel injection from the port fuel injection valve is stopped without executing EGR and air-fuel ratio feedback control, and an engine and an EGR valve are controlled such that fuel injection occurs only from the in-cylinder fuel injection valve.

Abstract: A system includes an internal combustion engine producing an exhaust gas, an aftertreatment system receiving the exhaust gas, the aftertreatment system including a particulate filter positioned upstream of an SCR catalyst component, and a urea injector operatively coupled to the aftertreatment system at a position upstream of the SCR catalyst component. The system further includes a controller that interprets an exhaust temperature value, an ambient temperature value, and a urea injection amount. The controller determines a urea deposit amount in response to the exhaust temperature value, the ambient temperature value, and the urea injection amount, and initiates a desoot regeneration event in response to the urea deposit amount. The desoot regeneration event includes operating the engine at a urea decomposition exhaust temperature.

Abstract: A device for generating exhaust gas including a exhaust gas channel and a system. The system includes: a plurality of Bragg gratings distributed in positions transversely to the direction of flow of an exhaust gas at the end of the exhaust gas channel; an optical wave guide structure includes at least one optical wave guide and the Bragg gratings; and a heating device arranged adjacently to the Bragg gratings and through which the Bragg gratings are subjected to heat, or a cooling device arranged adjacently to the Bragg gratings, through which the Bragg gratings can be subjected to cold. The optical wave guide structure and the heating device or the cooling device are arranged at the end of the exhaust gas channel at a distance from an outlet of the exhaust gas into the surroundings of the device.

Abstract: A method is provided for checking the functional capacity of a liquid-cooled exhaust manifold of an internal combustion engine, having an exhaust line connected to the exhaust manifold, in the course of which an exhaust gas sensor having an electrical heater is arranged. During the operation of the internal combustion engine, the electrical resistance of the exhaust gas sensor is determined, on the basis of which the current value of the exhaust gas temperature is evaluated, and compared to a target value of the exhaust gas temperature, which is expected at this point in the operation of the internal combustion engine. Depending on the result of the comparison, the functional capacity of the liquid-cooling of the exhaust manifold is estimated.

Abstract: An apparatus for controlling an internal combustion engine executes air-fuel ratio feedback control based on a detection result of an exhaust gas sensor and when the engine is shut down, stops energization of a heater of the exhaust gas sensor at a predetermined timing after shutdown of the engine, heater control of the exhaust gas sensor is executed, which is suitable for a case in which shutdown time of the engine is set long, and thus the exhaust gas sensor is protected from thermal shock. The control apparatus sets timing for stopping energization of a heater of an exhaust gas sensor after shutdown of the engine, to a point in time when a predetermined time set based on outside air temperature has elapsed, or a point in time when cooling water temperature of the engine has dropped to a predetermined temperature.

Abstract: A method for the self-diagnosis of an exhaust gas probe (20). The exhaust gas probe (20) has at least one heating element (26). The method includes a modeled heat output PH is determined for the heating element (26) by means of a computer program comparing parameters of the gas stream with a measured heat output, and determining, when the parameters of the gas stream exceeds the measured heat output by more than a defined tolerance limit, that one of the exhaust gas probe (20) is defective, and an exhaust gas section (17) in which the exhaust gas probe (20) is installed is faulty.

Abstract: In a method for heating a gas sensor (1), in particular an exhaust gas sensor for an exhaust system (5) of a motor vehicle (7), a temperature of the gas sensor (1) is determined and the heating process is influenced as a function of the temperature.

Abstract: An oxygen concentration sensor is disposed in an engine exhaust passageway. The alcohol concentration in the fuel used in the internal combustion engine is detected. A target impedance is set on the basis of the detected alcohol concentration. The actual impedance of a sensor element of the oxygen concentration sensor is detected. The heater output of the exhaust gas sensor is controlled so that the actual impedance becomes equal to the target impedance, whereby the temperature of the sensor element represented by the impedance becomes equal to a target temperature represented by the target impedance.

Abstract: A system and method for controlling engine operation includes a timer module that determines a time period from when a catalyst light-off mode is entered to when an oxygen sensor signal reaches an oxygen sensor threshold and a comparison module that generates an error signal and determines when the time period is above a time threshold.

Abstract: An inter-cylinder air-fuel ratio imbalance determination apparatus (determination apparatus) according to the present invention obtains, based on the output value of the air-fuel ratio sensor, an imbalance determination parameter which becomes larger as an air-fuel ratio fluctuation of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, during a parameter obtaining period. The determination apparatus energizes the heater of the air-fuel ratio sensor in such a manner that a temperature of the air-fuel ratio element during the parameter obtaining period is higher than a temperature of the air-fuel ratio element during a period other than the parameter obtaining period. Accordingly, the imbalance determination parameter is obtained while the responsiveness of the air-fuel ratio sensor is high, and thus, the inter-cylinder air-fuel-ratio imbalance determination having a high accuracy can be made.

Abstract: In an internal-combustion-engine control apparatus provided with an exhaust gas sensor control device that outputs a detection signal detected by an exhaust-gas sensor, while switching amplification factors of an amplification circuit or offset voltages of an offset circuit, it is determined whether the exhaust-gas sensor is in an activation state or not, and an electric current flowing into the exhaust-gas sensor is stopped, in the case where it is determined that the exhaust-gas sensor is in a non-activation state; the amplification factors of the amplification circuit are switched so that there is detected an air-fuel ratio signal at the time when an electric current flowing into the exhaust-gas sensor is stopped, and it is determined whether or not the offset circuit is abnormal, based on whether the respective air-fuel ratio signals at the amplification factors are within a predetermined range.

Abstract: A fault analysis method for a lambda probe of an internal combustion engine, in particular for detecting a heater input, has the following steps: measurement of an air ratio in the exhaust gas of the internal combustion engine by a lambda probe, control of the air ratio in the exhaust gas of the internal combustion engine by a lambda probe by a lambda controller intervention in accordance with the measured air ratio, and evaluation of the lambda controller intervention in order to detect a fault.

Abstract: The present invention relates to a fuel identification system and method normally applied to internal combustion engine vehicles of the flex-fuel type by means of which it is possible to identify the composition of the fuel used at each point in time, particularly the ratio used in a gasoline/ethanol blend or detect the presence of air or fuel in the vapor state in the fuel line, using the same device that heats the fuel.

Abstract: Various systems and methods are described for operating an engine in a vehicle in response to an ambient humidity generated from an exhaust gas sensor. One example method comprises, during engine non-fueling conditions, where at least one intake valve and at least one exhaust valve of the engine are operating, generating an ambient humidity from the exhaust gas sensor and, under selected engine combusting conditions, adjusting an engine operating parameter based on the ambient humidity.

Abstract: A degradation detector of an exhaust gas sensor is disclosed. The detector comprises a first heater resistance estimator (16) for estimating a resistance of a heater that heats the exhaust gas sensor, based on a device resistance of the exhaust gas sensor; a heater resistance calculator (17) for calculating a resistance of the heater, based on a heater current of the heater; and a degradation determiner (18) for determining whether the exhaust gas sensor is degraded, by comparing the estimated resistance of the heater and the calculated resistance of the heater.

Abstract: An air-fuel ratio sensor early activation feedback system and method includes an air-fuel ratio sensor for measuring an air-fuel ratio in an exhaust gas generated by an internal combustion engine and a heater for heating the air-fuel ratio sensor. A controller activates the heater prior to startup of the engine based on prior startup times for the engine.

Abstract: A heating module for an oxygen sensor comprises an estimated mass module, a cumulative mass module, and a temperature control module. The estimated mass module determines an estimated mass of intake air to remove condensation from an exhaust system after startup of an engine. The cumulative mass module determines a cumulative mass of intake air after the engine startup. The temperature control module adjusts a temperature of an oxygen sensor measuring oxygen in the exhaust system to a first predetermined temperature after the engine startup and adjusts the temperature to a second predetermined temperature when the cumulative air mass is greater than the estimated air mass, wherein the second predetermined temperature is greater than the first predetermined temperature.

Abstract: A vehicle-mounted engine control apparatus can accurately measure the resistance value of a label resistor arranged in an exhaust gas sensor for correcting characteristic variation thereof by using a reduced number of wires. An electric heater of the exhaust gas sensor, which is powered from a second power supply wire, as well as the label resistor and air fuel ratio measurement elements are connected to the apparatus which is powered from an on-vehicle battery through a first power supply wire. A power feed voltage of the apparatus is input to a multichannel AD converter through voltage dividing resistors, so that a positive end potential of the label resistor is measured alternatively. A negative end potential of the label resistor is input to the converter as a divided voltage thereof with a fixed resistor. The label resistance value is calculated from a fixed resistor current and a label resistor voltage.

Abstract: An oxygen sensor generating an accurate output concerning low-concentration exhaust gas positioned downstream of a three-way catalyst. The oxygen sensor includes an exhaust gas side electrode exposed to an exhaust gas; a reference gas side electrode exposed to a reference gas serving as a reference for oxygen concentration; and an electrolyte positioned between the exhaust gas side electrode and the reference gas side electrode. Further, a reduction mechanism positioned toward a front surface of the exhaust gas side electrode ensures the ratio of the amount of exhaust gas introduced to the exhaust gas side electrode to the amount of an exhaust gas flow to the outside of the oxygen sensor is smaller than the ratio of the amount of exhaust gas introduced to an electrode for the air-fuel ratio sensor to the amount of an exhaust gas flow to the outside of the air-fuel ratio sensor.

Abstract: A control apparatus for a gas sensor with a built-in heater is provided which can prevent damage to, deterioration of, and reduction in accuracy of detection of, a gas sensor. When an ignition switch is turned ON, supply of electricity to a heater 27 starts, and when the temperature in the vicinity of a gas sensor 15 (gas temperature of gas detection chamber 24) Ts becomes greater than a predetermined temperature #Ti at start, or when a predetermined electricity supply time after start of supply of electricity to the heater 27 has elapsed, the gas sensor 15 is started. The flow of off-gas is started simultaneously with starting of the gas sensor 15, or after starting. When the ignition switch is turned OFF, the flow of off gas is stopped, and the supply of electric power to the gas sensor 15 is stopped.

Abstract: An exhaust gas sensor for detecting oxygen concentration in exhaust gas is disposed in an exhaust pipe of an internal combustion engine. The sensor including a heater is controlled by a system that includes an electronic control unit. Water vapor contained in the exhaust gas is condensed on the sensor when the exhaust gas temperature is low. If the water condensation occurs while the sensor is heated by the heater, a sensor element may be cracked due to local cooling by the condensed water. To avoid the water condensation, the exhaust gas temperature is raised by retarding ignition timing of the engine for a certain period after the engine is started. After the exhaust gas is heated to a certain level, the sensor is heated. Alternatively, heating of the sensor is prohibited until the exhaust gas temperature becomes to a level at which no water condensation occurs. Thus, the cracking of the sensor element is avoided while making a delay of sensor activation minimal.

Abstract: in a method for heating a gas sensor (1), in particular an exhaust gas sensor for an exhaust system (5) of a motor vehicle (7), a temperature of the gas sensor (1) is determined and the heating process is influenced as a function of the temperature.

Abstract: An air-fuel ratio sensor early activation feedback system and method includes an air-fuel ratio sensor for measuring an air-fuel ratio in an exhaust gas generated by an internal combustion engine and a heater for heating the air-fuel ratio sensor. A controller activates the heater prior to startup of the engine based on prior startup times for the engine.

Abstract: A control input (DUT) for controlling a heater (13) which heats an active element (10) of an exhaust gas sensor (8) includes at least one of another component depending on the difference between temperature data of the active element (10) and a target temperature, a component depending on the target temperature, and a component depending on the temperature data of the active element (10). The control input is determined by an optimum control algorithm. A component depending on the temperature of an exhaust gas and the component depending on the target temperature are determined based on a predictive control algorithm. The temperature of the active element (10) of the exhaust gas sensor (8) is thus controlled stably at a desired temperature.

Abstract: A control system for an internal combustion engine includes an exhaust gas purifying device, an exhaust gas temperature sensor, and temperature estimating device. The exhaust gas purifying device is provided to an exhaust duct of the internal combustion engine. The exhaust gas temperature sensor is provided in the exhaust duct on an upstream side of the exhaust gas purifying device. The temperature estimating device estimates a first exhaust gas temperature on a downstream side of the exhaust gas purifying device through a transfer function, which is expressed by a plurality of identical first-order lag elements, based on a second exhaust gas temperature on the upstream side of the exhaust gas purifying device sensed by the exhaust gas temperature sensor.

Abstract: In one embodiment of an engine (1) in which air-fuel ratio feedback control is performed based on output of an exhaust gas sensor (100) disposed in an exhaust path, when the engine (1) starts in an extremely low temperature state (e.g., ?20 to ?30° C.), a heater (200) that heats a sensor element (110) of the exhaust gas sensor (100) is not powered immediately after the engine (1) starts, rather, power to the heater (200) is started when an engine coolant water temperature has reached a temperature near an air-fuel ratio feedback control starting water temperature.

Abstract: An internal combustion engine has at least one cylinder and an exhaust gas tract, in which an exhaust gas sensor, that can be heated in a controlled manner, is arranged. An exhaust gas temperature of an exhaust gas flowing in the exhaust gas tract is determined as a function of the heating power (P_HEAT) supplied to the exhaust gas sensor. An estimated value of the exhaust gas temperature is determined as a function of a physical model of the combustion of the air/fuel mixture and of the exhaust gas tract as a function of at least one operating variable of the internal combustion engine, but independent of the heating power supplied to the exhaust gas sensor. Model parameters of the physical model are adapted as a function of a deviation of the estimated value and of the exhaust gas temperature determined by the supplied heating power.