Abstract: A method for operating an exhaust gas cleaning device for a motor vehicle, the exhaust gas cleaning device has a vehicle catalytic converter, a first lambda probe arranged upstream of the vehicle catalytic converter, and a second lambda probe arranged downstream of the vehicle catalytic converter. A signal gradient is determined chronologically between a first signal jump of a measured value of the first lambda probe and a second signal jump of the measured value in a second direction opposite to the first direction, and a signal delay of a measured value of the second lambda probe is determined after the second signal jump.

Abstract: A method for operating a drive device having a drive unit producing exhaust gas and an exhaust gas posttreatment device designed as a vehicle catalytic converter for posttreatment of the exhaust gas. A first measured value describing the residual oxygen content in the exhaust gas is measured by a first lambda sensor arranged upstream of the exhaust gas posttreatment device and a second measured value describing the residual oxygen content in the exhaust gas is measured by a second lambda sensor arranged downstream of the exhaust gas posttreatment device. The combustion air ratio of a fuel-air mixture used to operate the drive unit is set during an at least temporarily performed normal operating mode on the basis of the first measured value, the second measured value, and a threshold value for the second measured value.

Abstract: A method for operating a drive device having a drive unit producing exhaust gas and an exhaust gas posttreatment device designed as a vehicle catalytic converter for posttreatment of the exhaust gas. A first measured value describing the residual oxygen content in the exhaust gas is measured by a first lambda sensor arranged upstream of the exhaust gas posttreatment device and a second measured value describing the residual oxygen content in the exhaust gas is measured by a second lambda sensor arranged downstream of the exhaust gas posttreatment device. The combustion air ratio of a fuel-air mixture used to operate the drive unit is set during an at least temporarily performed normal operating mode on the basis of the first measured value, the second measured value, and a threshold value for the second measured value.

Abstract: The present invention relates to a method for diagnosing an exhaust gas system of an internal combustion engine with at least one three-way catalytic converter, at least one four-way catalytic converter and at least one binary lambda sensor, wherein during the testing of the functional operability of the at least one binary lambda sensor and/or of at least one four-way catalytic converter on the basis of a lambda change with a changeover of the internal combustion engine from a lean operation to a rich operation following a thrust operation clearing out at least one three-way catalytic converter occurs.

Abstract: A method for operating a drive device with a drive unit and an exhaust gas purification device. The gas exhaust purification device is provided with a catalytic converter through which an exhaust gas stream can flow, as well as with a first lambda sensor arranged upstream of the catalytic converter in the exhaust gas stream and with a second lambda sensor arranged downstream of the catalytic converter in the exhaust gas stream, wherein an oxygen filling value of an oxygen storage device of the catalytic converter is determined on the basis of a first lambda signal provided by the first lambda signal sensor as well as an offset value.

Abstract: In a method of operating a drive device, a probe temperature of an exhaust gas exhaust gas probe in an exhaust tract is measured, as the exhaust gas probe is heated by a probe heater. A temperature growth value representative of an increase in temperature of the exhaust gas probe is determined during heating of the exhaust gas probe, and the presence of a defect of the probe heater is recognized, when the temperature growth value deviates from an input value.

Abstract: A method for operating a drive device with an internal combustion engine and an exhaust gas tract having a storage catalytic converter for purifying exhaust gas, a first lambda probe disposed upstream of the storage catalytic converter and a second lambda probe disposed downstream of the storage catalytic converter, includes determining a lambda value for controlling a mixture composition for the internal combustion engine based on a measurement signal from the first lambda probe and an offset value. The offset value is determined with a trim control when a measurement signal of the second lambda probe is in a normal operating range of values, and is adjusted in a regeneration period, during which the storage catalytic converter regenerated, with a predetermined correction value when the measurement signal of the second lambda probe is outside the normal operating range of values. A corresponding drive device is also disclosed.

Abstract: A method for diagnosing a measurement of a pressure difference. The measurement is carried out with a measuring arrangement for a component of an exhaust gas device, the input of which is connected to a first exhaust gas pipe and the output of which is connected to a second exhaust gas. The measuring arrangement is provided with a pressure difference measuring device and with a first and second pressure measurement point, which are connected to the pressure difference measuring device for measuring the pressure difference between a pressure measured at the first pressure measurement point and at the second pressure measured at the second pressure measurement point. The pressure difference between the two pressure measurement points is measured with a pressure difference between measuring device.

Abstract: In a method of operating an exhaust emission control device, the presence of an actual pressure loss of a particulate filter is determined, and a model pressure loss is determined as a function of a state variable. On the basis of the actual pressure loss and the model pressure loss a pressure quotient is determined and a condition of the particulate filter is ascertained in a diagnostic mode in response to the pressure quotient.

Abstract: In a method of operating a drive device, a probe temperature of an exhaust gas exhaust gas probe in an exhaust tract is measured, as the exhaust gas probe is heated by a probe heater. A temperature growth value representative of an increase in temperature of the exhaust gas probe is determined during heating of the exhaust gas probe, and the presence of a defect of the probe heater is recognized, when the temperature growth value deviates from an input value.

Abstract: A method for operating an internal combustion engine includes the steps of determining an oxygen filling state of an oxygen storage of a catalytic converter by way of a first lambda signal provided by a first lambda probe and an offset value, the first lambda probe being arranged in an exhaust gas stream upstream of the catalytic converter; when a second lambda signal provided by a second lambda probe arranged in the exhaust gas stream upstream of the catalytic converter falls below a lower lambda signal threshold, setting the oxygen filling state to a first value corresponding to an empty oxygen storage and/or when the second lambda signal exceeds a upper lambda signal threshold setting the oxygen filling state to a second value corresponding to a full oxygen storage; immediately thereafter regulating the oxygen filling state during at least one regulation time period to a target filling state; and after expiration of the regulation time period adjusting the offset value by way of the second lambda signal.

Abstract: In a method of operating an exhaust emission control device, the presence of an actual pressure loss of a particulate filter is determined, and a model pressure loss is determined as a function of a state variable. On the basis of the actual pressure loss and the model pressure loss a pressure quotient is determined and a condition of the particulate filter is ascertained in a diagnostic mode in response to the pressure quotient.

Abstract: A method for operating a drive device with an internal combustion engine and an exhaust gas tract having a storage catalytic converter for purifying exhaust gas, a first lambda probe disposed upstream of the storage catalytic converter and a second lambda probe disposed downstream of the storage catalytic converter, includes determining a lambda value for controlling a mixture composition for the internal combustion engine based on a measurement signal from the first lambda probe and an offset value. The offset value is determined with a trim control when a measurement signal of the second lambda probe is in a normal operating range of values, and is adjusted in a regeneration period, during which the storage catalytic converter regenerated, with a predetermined correction value when the measurement signal of the second lambda probe is outside the normal operating range of values. A corresponding drive device is also disclosed.

Abstract: A process is proposed for determining the lambda value upstream from the exhaust catalytic converter in which variation in the lambda value (??) from the stoichiometric value is determined on the basis of variation in the charging (?OSC) of the oxygen reservoir (7) of the exhaust catalytic converter (6) and variation in the charging (?OSC) of the oxygen reservoir (7) is ascertained from the voltage signal (U?downstream) of a binary lambda probe (8) associated with the exhaust catalytic converter (6). In accordance with the proposal a control probe upstream from the exhaust catalytic converter can be omitted; this results in cost savings.

Abstract: A method for operating an internal combustion engine includes the steps of determining an oxygen filling state of an oxygen storage of a catalytic converter by way of a first lambda signal provided by a first lambda probe and an offset value, the first lambda probe being arranged in an exhaust gas stream upstream of the catalytic converter; when a second lambda signal provided by a second lambda probe arranged in the exhaust gas stream upstream of the catalytic converter falls below a lower lambda signal threshold, setting the oxygen filling state to a first value corresponding to an empty oxygen storage and/or when the second lambda signal exceeds a upper lambda signal threshold setting the oxygen filling state to a second value corresponding to a full oxygen storage; immediately thereafter regulating the oxygen filling state during at least one regulation time period to a target filling state; and after expiration of the regulation time period adjusting the offset value by way of the second lambda signal.

Abstract: In a method for operating an exhaust gas purifying device, with at least one catalyst for filtering exhaust gas and at least one lambda sensor arranged in the exhaust gas, an end of a time period assigned to a maximum or minimum of a delayed signal value supplied by the lambda sensor is determined in that a variable value tracks the signal value and, if the signal value falls short of or exceeds the variable value by a specific difference value, the end of the time period is determined. The end of a time period is corrected on the basis of the time constant of the delay.

Abstract: The output signal of a pre-catalytic converter lambda probe and the output signal of a controller are used to determine an inherent delay time of the pre-catalytic converter lambda probe, for example due to aging of the probe, by measuring, for example, the separation between maxima in these output signals. The pre-catalytic converter lambda probe is installed in an exhaust gas system of an arrangement wherein an internal combustion engine operated under controlled conditions. The determined delay time can be used to determine the oxygen storage capacity of an oxygen store associated with a catalytic converter in the arrangement by determining with the pre-catalytic converter lambda probe the start of a time interval over which integration takes place, and determining the actual end time of the integration by adding the delay time to an end time determined from an output signal of the post-catalytic converter lambda probe.

Abstract: The invention relates to a method that is intended for operating an internal combustion engine of a motor vehicle and that flushes the temporarily unused injection valves with fuel for the purpose of preventing and/or removing deposits. In order to make possible in a simple way a complete conversion of the undesired exhaust gas constituents in a catalytic converter of an exhaust gas aftertreatment system of the internal combustion engine when the internal combustion engine is running, the invention proposes flushing the temporarily unused injection valves with fuel during an overrun mode of the internal combustion engine.

Abstract: An offset in the signal of a pre-catalytic converter lambda probe of an exhaust gas system of an internal combustion engine affects a measured oxygen intake storage capacity and a measured oxygen removal storage capacity of an oxygen store with identical magnitude, but with opposite mathematical sign, so that their sum is independent of the offset. The oxygen intake storage capacity and the oxygen removal storage capacity are hereby determined until the output signal of the post-catalytic converter probe exceeds an intermediate threshold value of, for example, 0.45 V for intake and 0.8 V for removal. Exposure of the oxygen store to rich and/or lean exhaust gas is maintained after this threshold value has been crossed to ensure that the oxygen store is indeed sufficiently filled after the oxygen intake storage capacity has been measured, or is sufficiently emptied after the oxygen removal storage capacity has been measured.

Abstract: The invention relates to a process for the lambda control of an internal combustion engine with exhaust catalyst, having a lambda probe mounted downstream from the exhaust catalyst as control probe, a probe by means of which a post-catalyst lambda value of an exhaust gas flow leaving the exhaust catalyst is registered. Furthermore, a lambda control mechanism is provided by means of which the post-catalyst lambda value is set to a predetermined value such that a specific, predetermined degree of oxygen charging of an oxygen reservoir of the exhaust catalyst is set, the value predetermined for the degree of charging with oxygen of the oxygen reservoir being predetermined as a function of a predetermined degree of conversion of the exhaust catalyst.