Abstract: A control system includes an electrical heating catalyzer, a measuring device and an electronic control unit. The measuring device measures an insulation resistance between a catalyst carrier and case of the electrical heating catalyzer. The electronic control unit determines that the electrical heating catalyzer has a failure when a variation width of the insulation resistance is smaller than or equal to a set value in a historical variation in the insulation resistance measured by the measuring device.

Abstract: There are disclosed an information-display-equipped electric-heating-type heater, and a method of using the above information. An information-display-equipped electric-heating-type heater includes a tubular honeycomb structure made of a conductive material and having porous partition walls to define and form a plurality of cells which become through channels for a fluid and extend from one end face to the other end face, and a circumferential wall positioned in an outermost circumference; and a pair of electrodes disposed on the circumferential wall of the honeycomb structure, and information concerning a heater performance of the electric-heating-type heater is displayed in the honeycomb structure.

Abstract: A method that includes in-vehicle systems and practices for determining whether a NOx sensor in an exhaust stream is performing properly.

Abstract: A vehicle includes: an engine; an EHC (electrically heated catalyst) electrically heated for purifying exhaust gas of the engine; a temperature sensor for sensing the temperature of the EHC; and an ECU that controls the EHC in temperature. The ECU performs a first estimation process and a second estimation process to estimate the temperature of the EHC and accordingly controls electric power applied to energize the EHC, the first estimation process being performed to estimate the temperature of the EHC based on an output of the temperature sensor before the engine starts, the second estimation process being performed to estimate the temperature of the EHC based on the temperature of the exhaust gas emitted by the engine after the engine is started.

Abstract: A catalyst degradation detection method for use with a zero ceria catalyst. The method uses techniques to measure transient responses to engine control events of upstream and downstream sensors to determine catalyst degradation and performance. By measuring transient behavior, the method can determine catalyst degradation and performance based on the limited oxygen storage of precious metal catalysts that do not include added ceria or other materials with high oxygen capture rates.

Abstract: The invention relates to an arrangement (1) for operating an exhaust gas post-treatment device, particularly of a motor vehicle, wherein the arrangement (1) comprises a plurality of consumers (3-12) and a controller (2), wherein the controller (2) comprises at least one switching device (13) for switching the consumers (3-12) on and off. According to the invention, the consumers (3-12) are grouped according to function, and connected to one switch (17-21) each of the switching device (13). The invention further relates to a method for operating an exhaust post-treatment device.

Abstract: In a diesel engine equipped with a system for automatic regeneration of a particulate filter, an automatic regeneration mode is inhibited in the case where there is recorded a number higher than a pre-set threshold of unfavorable event. When the automatic regeneration mode is inhibited, an on-demand regeneration mode is simultaneously enabled, which can be activated manually by the driver. If an on-demand regeneration is not performed before the vehicle has covered a certain mileage since the automatic regeneration mode was inhibited, the vehicle is set in a condition of limited performance.

Abstract: An example method includes interpreting an NH3 composition value at a position upstream of a selective reduction catalyst (SCR) element fluidly disposed in the exhaust conduit of an engine, interpreting a NOx composition value at a position downstream of the SCR element, and determining an NH3 sensor rationality threshold in response to the upstream NH3 composition value. The method further includes determining an NH3 sensor health value as indicating a sensor failure in response to the downstream NOx composition value exceeding the NH3 sensor rationality threshold.

Abstract: An internal combustion engine operating at a lean air/fuel ratio includes a reductant injection system configured to dispense reductant into an exhaust gas feedstream upstream of a selective catalytic reduction device. The reductant injection system includes a reductant delivery system fluidly coupled to a reductant dispensing device that is configured to dispense the reductant. A method for monitoring the reductant injection system includes commanding the reductant dispensing device to dispense reductant at a prescribed reductant flowrate, controlling the reductant delivery system to a preferred operating state, monitoring operation of the reductant delivery system and estimating a reductant flowrate as a function of the monitored operation of the reductant delivery system, and diagnosing operation of the reductant injection system as a function of the prescribed reductant flowrate and the estimated reductant flowrate.

Abstract: A control apparatus for an internal combustion engine is provided, the control apparatus being capable of effectively suppressing the inflow of fresh air into a catalyst due to an operational delay of the valve stop mechanism when an execution request for fuel cut is issued. There is provided a valve stop mechanism capable of changing the operational states of intake valves and exhaust valves between a valve operating state and a valve closed/stopped state. The operational states of the intake and exhaust valves are changed into the valve closed/stopped state, if the engine rotational speed decreases to or below a predetermined rotational speed when the engine rotational speed is higher than the predetermined rotational speed in a case where an execution request for fuel cut is detected and the temperature of the catalyst is not lower than a predetermined temperature during operation of an internal combustion engine.

Abstract: The present invention provides for a system for controlling NOx emissions based on the calculation of an error given by the difference between a first measured value obtained from a NOx sensor (7) and a second one estimated from a NOx estimation. Said sensor (7) can be used in an adaptation loop, where an open-loop or closed-loop EGR control system is adapted such that the expected NOx emissions (from the EGR controller) match the ones measured with the NOx sensor under steady-state conditions.

Abstract: A control device for an internal combustion engine includes a SCR system disposed in an exhaust passage and a particulate matter sensor disposed downstream of the SCR system. The control device applies a particulate matter trapping voltage to the particulate matter sensor, and acquires an output of the particulate matter sensor at a first timing after the start of application of the particulate matter trapping voltage. The control device executes predetermined control in accordance with the output. If a second timing at which an integrated operating time period of the internal combustion engine in a predetermined operating state in which urea-related substances discharged to downstream of the SCR system increase reaches a reference time period after starting application of the particulate matter trapping voltage is earlier than the first timing, the control device stops the predetermined control.

Abstract: Method for controlling regeneration within an after-treatment component of an engine comprises receiving an upstream temperature signal, receiving a downstream temperature signal, and calculating a temperature difference based on a difference between the upstream temperature signal and the downstream temperature signal. The temperature difference is compared to a predetermined temperature change limit to determine whether the temperature difference is less than or greater than the predetermined temperature change limit. If the temperature difference is less than the predetermined temperature change limit, an estimate of accumulated particulate matter in the after-treatment component is calculated using a primary soot accumulation model. If the temperature difference is greater than the predetermined temperature change limit, an estimate of accumulated particulate matter in the after-treatment component is calculated using a secondary soot accumulation model.

Abstract: An exhaust emission control system of an internal combustion engine includes: a bypass passage (22) provided in an exhaust passage (14) of the engine and arranged to bypass a main passage (16) as a part of the exhaust passage, a NOx adsorbent (28) provided in the bypass passage and adapted to adsorb at least NOx as one of components contained in exhaust gas, a channel switching device (30) that switches a channel of the exhaust gas between the main passage and the bypass passage, an adsorption control device (50) that controls the channel switching device, based on operating conditions of the engine, so as to cause the exhaust gas to flow through the bypass passage, and an adsorbing capability determining device (50) that determines, when the adsorbing capability of the NOx adsorbent degrades, whether the degradation in the adsorbing capability is a surmountable degradation from which the NOx adsorbent can recover, or an insurmountable degradation from which the NOx adsorbent cannot recover.

Abstract: An adaptive method is used for LNT desulfation and regeneration. The desulfation method involves adapting the amount of sulfur loading to trigger a desulfation event in accordance with the current adsorption capacity of the LNT. The method involves monitoring the current sulfur loading and the current LNT adsorption capacity. This data is used to calculate a loading amount “trigger”, whose value varies over the LNT lifetime. Whenever this trigger amount is reached, a desulfation event is performed. The regeneration method is similar, with the baseline data and loading threshold being determined by NOx loading rather than sulfur loading.

Abstract: A catalyst degradation detection device, determines whether a three-way catalyst has degraded on the basis of the maximum value of the amount of oxygen stored by the catalyst. When determining whether the three-way catalyst has degraded, the amount of stored oxygen is calculated, and the responsiveness of change in the output signal of an oxygen sensor to oxygen concentration change in catalyst-downstream exhaust is measured. Then, on the basis of the responsiveness of the oxygen sensor which measured the oxygen storage amount, the oxygen storage amount is corrected by reducing the same such that the worsened the measured responsiveness relative to a reference value, the greater the reduction in the oxygen storage amount used in determining whether the three-way catalyst has degraded. The corrected oxygen storage amount used is prevented from deviating from the correct value on the basis of a worsening of the responsiveness of the oxygen sensor.

Abstract: Aggregation of particulate matter is facilitated. Provision is made for an electrode that is arranged in an exhaust passage of an internal combustion engine with a voltage to be applied thereto being able to be changed, a detection device that detects an electric current passing through the electrode, a determination device that determines whether a pulse current has been generated in the electric current detected by the detection device, and a control device that reduces the voltage to be applied more than that at this time in cases where a determination has been made by the determination device that a pulse current has been generated.

Abstract: An exhaust gas treatment system for an internal combustion engine for determining a total amount of sulfur that is stored on at least one aftertreatment device is provided. The exhaust gas treatment system includes a control module that monitors operation of the internal combustion engine for an amount of fuel consumed and an amount of oil consumed by the internal combustion engine. The control module includes a sulfur adsorption module and a total sulfur storage module. The sulfur adsorption module determines a rate of sulfur adsorption in at least one aftertreatment device. The rate of sulfur adsorption is based on the amount of fuel consumed and the amount of oil consumed. The total sulfur storage module is in communication with the sulfur adsorption module. The total sulfur storage module determines the total amount of sulfur stored based on the rate of sulfur adsorption.

Abstract: In a method for preventing clogging of a urea injection nozzle in an after-run operation of a selective catalytic reduction (SCR) system which supplies urea stored in a urea tank through a supply module, a urea injection nozzle and a urea line connecting the supply module and the urea injection nozzle, the method may include an emptying step where the urea is withdrawn into the urea tank by creating negative pressure in the supply module and a pressure equilibrium step where the pressure in the supply module is recovered by stopping creation of negative pressure in the supply module, wherein in the pressure equilibrium step, whether to forcibly inject the urea is controlled on the basis of pressure after a predetermined time has passed since the pressure equilibrium step began.

Abstract: The present invention provides an exhaust emission purifying apparatus having a liquid level measuring device in which, when a liquid level (measured liquid level) measured by a liquid level indicator of a sensor is equal to or than a measurable lower limit, the measured liquid level is output. On the other hand, when the measured liquid level is less than the measurable lower limit, the liquid level estimated based on a consumption of a liquid reducing agent or its precursor in a reducing agent tank and a tank cross-sectional area is output. The liquid level of the liquid reducing agent or its precursor is estimated in a range in which the liquid level may not be accurately measured due to the presence of a concentration meter, whereby the liquid level can be measured over a wide range.

Abstract: A method for an exhaust after treatment system of an engine including at least one selective catalyst reaction (SCR), at least one clean up catalyst downstream from the SCR, a urea injector upstream of the SCR and a first NOx sensor downstream the clean up catalyst. The method includes the steps of injecting a predetermined amount of urea by the injector, providing a second NOx sensor between the SCR and the clean up catalyst, measuring the NOx content received by the first NOx sensor, measuring the NOx content received by the second NOx sensor, comparing the first and the second NOx content with each other, and reducing the predetermined amount of urea if the first NOx sensor measures a higher NOx content than the second NOx sensor.

Abstract: In an exhaust gas purification apparatus of an internal combustion engine, there is provided a technique capable of suppressing a reduction in exhaust gas purification performance. The apparatus includes: an exhaust gas purification catalyst (6) that is arranged in an exhaust passage of the internal combustion engine for purifying an exhaust gas; an adsorption device (5) that is arranged at an upstream side of the exhaust gas purification catalyst, rises in temperature up to an upper limit temperature due to heat generated by adsorption thereto of an incoming first component, and falls in temperature after its temperature has reached said upper limit temperature; and a heat generating component supply unit (10) that supplies a second component which generates reaction heat in the exhaust gas purification catalyst, before the temperature of the adsorption device begins to fall.

Abstract: In an internal combustion engine that is capable of performing a fuel supply cut control (FC control), a performance of the FC control is suspended, in a case where, when the performance of the FC control is requested to initiate, a deviation between a solid solution of an active element in a carrier and a target solid solution is equal to or more than a predetermined upper limit value and a catalyst temperature is equal to or more than a predetermined upper limit temperature.

Abstract: An exhaust treatment fluid system includes a tank housing for storing an exhaust treatment fluid. A suction tube includes a first end positioned within the housing. A first sensor is positioned within the tank housing for determining at least one of a fluid level and a concentration of the exhaust treatment fluid. A skirt is positioned in the tank to peripherally surround the first sensor.

Abstract: An exhaust purifying system includes: a catalytic device supplied with electric power from a power supply unit; a first connecting unit connecting one end of the catalytic device to a negative electrode node of the power supply unit; a second connecting unit connecting the other end of the catalytic device to a positive electrode node of the power supply unit; a leak detecting unit detecting leak from the power supply unit; and a control unit controlling opening and closing of each of the first and second connecting units. When leak is not detected by the leak detecting unit in a leak check state where one of the first and second connecting units is closed and the other is opened, the control unit closes the other and applies current through the catalytic device, and when leak is detected in the leak check state, the control unit does not apply the current through the catalytic device.

Abstract: A method for operating an internal combustion engine having an exhaust emission control unit with at least one exhaust emission control component which acts catalytically and/or by filtration involves operating the internal combustion engine, during a cold start or warm-up of the internal combustion engine, using a cold start engine operating process with predefined values for predefined internal combustion engine operating variables. The cold start and/or the warm-up of the internal combustion engine is controlled or regulated as a function of soot loading of a particle filter of the exhaust emission control unit.

Abstract: The invention relates to a method for controlling a system for treating NOx in an exhaust line of an internal combustion engine, said system comprising means for introducing a reducing agent into the exhaust line upstream of an NOx reduction catalyst. The invention is characterized in that it consists in estimating the efficiency of the treatment in relation to a maximum conversion potential obtained if the ratio between the quantity of injected reducer and the quantity of NOx in the gas complies with a given set value and if the mass of reducing agent stored in the catalyst complies with a given storage set value.

Abstract: An engine and related control system determine an amount of fuel diluting the engine oil in the oil pan. Such information can be used to recommend an oil change and to estimate a fraction of biodiesel in the fuel supplied to the engine. According to one embodiment, actual oil volume in the oil pan is based on a signal from a level sensor in the oil and a theoretical oil volume is determined based on initial oil volume and fuel entering the oil in the oil pan, fuel leaving the oil pan due to evaporation, and oil being consumed in the combustion chamber. Based on the difference between the actual and theoretical oil volumes, a proportion of heavy fuel components or biodiesel can be determined and transmitted to an engine control system.

Abstract: An exhaust purification system is provided that can appropriately grasp the NOx concentration or NH3 concentration on a downstream side of a selective reduction catalyst. A separation filter of the system models a downstream NOx estimated value (NOx_DW_hat) of the catalyst with a value obtained by multiplying a coefficient (Kscr) by an output (NOx_UP) of an upstream-side NOx sensor. The separation filter includes transient extraction filters that block a stationary component and allow a frequency band corresponding to an increase-decrease request of drive power from the driver to pass from the downstream NOx sensor output (Ynox) and upstream NOx sensor output (NOx_UP), and calculate filter values (Ynox_f, NOx_UP_f) of each; and an identifier that identifies the coefficient (Kscr) so that error (eid) between the filter value (Ynox_f) and a value (NOx_DW_hat_f) obtained by multiplying the purification coefficient (Kscr) by the filter value (NOx_UP_f) becomes a minimum.

Abstract: A method includes determining a first NOx conversion efficiency (?) value and determining that a diesel exhaust fluid (DEF) level has increased a threshold amount. Further, the method includes determining a second NOx conversion ? value and comparing the first NOx conversion ? value and the second NOx conversion ? value, determining a NOx conversion ? change in response to comparing, and determining a DEF quality indicator in response to the NOx conversion ? change.

Abstract: An exhaust gas treatment system for an internal combustion engine is provided having an exhaust gas conduit, a diesel exhaust fluid (“DEF”) source, a selective catalytic reduction (“SCR”) device, a NOx sensor, and a control module. The DEF source supplies a DEF having a quality factor. The NOx sensor is in fluid communication with the exhaust gas conduit. The NOx sensor is located downstream of the SCR device and is configured for detecting a NOx concentration value. The control module is in communication with the DEF source and the NOx sensor. The control module stores a diagnostic adaptation factor and an expected NOx value. The control module includes a dosing module for determining a controls adaptation factor that is based on a deviation between the NOx concentration value and the expected NOx value. The diagnostic adaptation factor is selectively updated with the controls adaptation factor.

Abstract: A detection unit that is arranged in an exhaust passage of an internal combustion engine configured to detect a state of the exhaust gas, addition unit configured to add the additive agent into the exhaust passage, a catalyst that is arranged at the downstream side of the detection unit and the addition unit so as to receive a supply of the additive agent from the addition unit, determination unit configured to determine whether detection accuracy of the detection unit drops due to the additive agent to be added from the addition unit, and stop unit configured to stop detection of the state of the exhaust gas by the detection unit in cases where it is determined by the determination unit that the detection accuracy of the detection unit drops.

Abstract: A system for a fluid tank for storing a urea solution in a motor vehicle, the system including a first float having a first density and a second float having a second density, the first and second floats being movably arranged on a guide in the fluid tank, the first density is less than a density of the urea solution at a reference temperature but greater than a density of water at the reference temperature, and the second density is less than the density of water at the reference temperature. The system further includes a control system configured to receive signals indicative of a level of the floats, and to generate an anomaly signal in response to detecting sinking of the first float and floatation of the second float.

Abstract: A control pressure switching valve is disposed between a displacement regulator and a pressure control valve. The control pressure switching valve is switched between a control position (j), in which a load sensing control pressure (PLS) is permitted to be outputted from the pressure control valve to the displacement regulator, and a control release position (k), in which the load sensing control pressure (PLS) to be outputted to the displacement regulator is reduced to a prescribed low pressure value. When the regeneration of a filter is determined to be necessary, the controller switches the control pressure switching valve to the control release position (k). When the load sensing control pressure (PLS) is reduced to the low pressure value with the control pressure switching valve switched to the control release position (k), the displacement regulator increases a delivery displacement of a hydraulic pump, thereby increasing rotational load of an engine.

Abstract: It is determined quickly whether there is a shortage in reducing agent supplied to an NOx selective reduction catalyst. After it is determined that a quantity of reducing agent equal to or larger than a predetermined quantity is absorbed in the NOx selective reduction catalyst on the assumption that there is no abnormality in reducing agent supply unit, the supply of a quantity of reducing agent needed to reduce a quantity of NOx flowing into the NOx selective reduction catalyst is started. A determination of an abnormality in the reducing agent supply unit is made based on the NOx removal rate after the lapse of a predetermined period of time since the start of the supply of reducing agent. The NOx removal rate becomes lower when there is an abnormality in the reducing agent supply unit.

Abstract: A method of assessing non-methane hydrocarbon (NMHC) conversion efficiency in a diesel after-treatment (AT) system having a diesel oxidation catalyst (DOC) arranged upstream of a diesel particulate filter (DPF) includes regenerating the AT system. Additionally, the method monitors DOC inlet and outlet temperatures during the regeneration. The method also assesses whether the DOC is operating at or above threshold efficiency by determining a DOC inlet/outlet temperature difference and comparing the determined inlet/outlet temperature difference with a threshold inlet/outlet temperature difference. The method also monitors DPF outlet temperature if the DOC is operating at or above the threshold efficiency and determines a DOC temperature/DPF outlet temperature difference.

Abstract: A method of supplying fuel vapor to an exhaust aftertreatment device of a motor vehicle is provided. The method includes evaporating fuel on a voltage-biased, resistive heating element, the element set in an enclosure configured to release fuel vapor to the exhaust-aftertreatment device, and indicating that the element is degraded if a current flowing through the element is less than a threshold current. In some embodiments, the threshold current is based on the ambient temperature and/or the amount of fuel in the enclosure.

Abstract: A method for monitoring an exhaust after-treatment system that doses an exhaust treatment fluid held from a tank into an exhaust stream. The method includes determining a first temperature of the exhaust treatment fluid in the tank using a temperature sensor. If the first temperature of the exhaust treatment fluid is less than a predetermined temperature, a heater is activated to increase the first temperature of the exhaust treatment fluid. The increasing first temperature is then monitored relative to the predetermined temperature. Then, a second temperature when a phase change of the exhaust treatment fluid occurs is detected. The detected second temperature is then compared to the predetermined temperature to determine whether the exhaust treatment fluid is of sufficient quality, or to determine whether the temperature sensor is rational.

Abstract: A method for protecting an exhaust aftertreatment system of an internal combustion engine from deterioration by selectively diverting exhaust gasses from the engine away from a component of the exhaust aftertreatment system includes assessing a status of an operating condition associated with a physical condition of the component of the internal combustion engine. The status of the operating condition is compared with a threshold value that corresponds with deterioration of the physical condition of the component. A valve upstream of the component is moved to a first position to open a bypass fluid path directing exhaust gasses around the component when the status of the operating condition meets the threshold value to reduce deterioration of the component. The valve is moved to a second position to close the bypass fluid path thereby directing exhaust gasses to the component when the status of the operating condition does not meet the threshold.

Abstract: The exhaust gas purifying device of an internal combustion engine includes: an electrically heated catalyst which is provided on an exhaust passage of the internal combustion engine, which purifies the exhaust gas drawn to the exhaust passage, and is warmed by electrification; and an electrification characteristic setting unit which set an electrification characteristic indicating a characteristic of an electrification resistance value in the electrically heated catalyst, in accordance with an electrification condition at a time of starting the electrification of the electrically heated catalyst. Thus, various determinations and controls relating to the electrically heated catalyst and using the electrification characteristic can be accurately performed.

Abstract: An electronic control device calculates the maximum actual oxygen storage capacity of a catalyst. The gradient of a linear expression formed between the catalyst temperature and the maximum oxygen storage capacity of the catalyst is stored for each degradation level of the catalyst. The gradient can be learned in accordance with the same temperature of the catalyst and the maximum actual oxygen storage capacity. When the maximum actual oxygen storage capacity is calculated, it is revised in accordance with the temperature of the catalyst, a reference temperature, the linear expression, and the learned gradient. The revised maximum oxygen storage capacity which is the maximum oxygen storage capacity when the temperature of the catalyst during the same calculation period is equal to the reference temperature is then calculated. If a response delay is detected in the output of an oxygen sensor, the gradient of the learned linear expression is discarded.

Abstract: An exhaust gas treatment system for an internal combustion engine may have a reductant delivery system that delivers reductant to an exhaust stream in an exhaust aftertreatment system. A temperature sensor may be positioned in or near the flow of reductant and exhaust to measure the temperature of the reductant and exhaust. A change in temperature over time, such as an increase, decrease, or change in variation amplitude, may indicate the presence of a reductant deposit in the system. Detection of the deposit may initiate a regeneration cycle in which the operating characteristics of the system change to eliminate the reductant deposit to prevent it from hindering the performance of the exhaust aftertreatment system.

Abstract: A system for detecting pollution by a poisonous material for an air exhauster of a vehicle may include a temperature sensor provided to the flow line of an exhaust gas and having a catalyst material that causes an exothermic reaction with a pollution material in the exhaust gas, and a controller which stores a standard temperature value of the temperature sensor and operates in such a manner that the exhaust gas may be heated under control of an engine control unit when the temperature value drops by a predetermined amount from the standard temperature value, and that the catalyst material may be determined to have deteriorated when a measured temperature value after heating may be less than the standard temperature value, so that the standard temperature value may be replaced with the measured temperature value, and to a detection method using the same.

Abstract: Embodiments for reducing ammonia slip are provided. In one example, a method for reduction of ammonia emissions from an engine exhaust gas aftertreatment device with an SCR catalyst comprises determining a concentration of NOx and/or ammonia in the exhaust gas aftertreatment device, comparing a determined value of NOx and/or ammonia concentration with a nominal value for NOx and ammonia, respectively, and if an actual or shortly forecasted ammonia concentration is above the respective nominal value, triggering engine conditions with higher exhaust NOx concentration. In this way, ammonia slip may be reduced without degrading fuel economy.

Abstract: A system and method includes an exhaust aftertreatment system for an internal combustion engine having a reductant stored in a solid storage media. The reductant is released by heating the solid storage media to convert the reductant to gaseous form. The system and method determines the quality of the solid storage media by measuring operating parameters of the aftertreatment system and comparing the operating parameters to expected parameters stored in a memory of a controller of the system.

Abstract: An exhaust purification system is provided that can continuously maintain a NOx purification rate to be high while suppressing the occurrence of ammonia slip. The exhaust purification system includes a slip determination portion 34 that determines the occurrence of ammonia slip based on an output value NH3CONS of an ammonia sensor 26. A reference injection amount calculating portion 31 calculates a reference injection amount GUREA—BS based on a parameter correlating to an operating state of an engine. A switching injection amount calculating portion 32 decreases in amount a urea injection amount GUREA by setting a switching injection amount GUREA—SW to a negative value in response to having determined that ammonia slip has occurred, and increases in amount the injection amount GUREA by setting the switching injection amount GUREA—SW to a positive value in response to a storage amount estimated value STUREA having fallen below a predetermined switch storage amount STUREA—SW.

Abstract: A method for preventing choking of a urea injection nozzle in after run operation on a SCR system which supplies urea stored in a urea tank through a supply module, a urea injection nozzle and a urea line connecting the supply module and the urea injection nozzle, the method for preventing choking of a urea injection nozzle includes comparing pressure within the supply module with a first predetermined pressure (Pa), open controlling the urea injection nozzle when the pressure in the supply module is higher than the first predetermined pressure (Pa) or repeating open/close controlling the urea injection nozzle when the pressure in the supply module is lower than the first predetermined pressure (Pa), pressure equilibrium which recovers pressure in the supply module and stopping the after run operation when the balancing pressure is completed.

Abstract: An apparatus determines whether or not there is a malfunction in a reducing agent supply apparatus having a reducing agent addition valve provided in the exhaust system of an internal combustion engine. The reducing agent addition valve injects liquid reducing agent into the exhaust gas. A temperature sensing unit that senses the temperature of the exhaust gas is provided at a position in the exhaust system of the internal combustion engine through which the reducing agent injected through the reducing agent addition valve passes. As the reducing agent is injected through the reducing agent addition valve, the temperature decrease of the exhaust gas at the position through which the reducing agent passes is calculated by a temperature decrease calculation unit. Whether or not there is a malfunction in the reducing agent supply apparatus is determined by a diagnosis unit, based on the temperature decrease of the exhaust gas.

Abstract: A method for monitoring the capability of a catalytic converter to convert nitrogen monoxide into nitrogen dioxide in the exhaust gas of an internal combustion engine, the catalytic converter being arranged in an exhaust gas duct of the internal combustion engine and the catalytic converter being followed downstream by a collecting particle sensor. It is in this case provided that, in a monitoring cycle, a decrease in the particle loading of the particle sensor during the operation of the internal combustion engine under predetermined operating conditions is taken to conclude an adequate capability of the catalytic converter to convert from nitrogen monoxide to nitrogen dioxide.

Abstract: The invention relates to an arrangement (1) for operating an exhaust gas aftertreatment device, in particular of a motor vehicle, having a plurality of active sensors (3-8) and a control device (2) that comprises at least one voltage supply unit (9) to which the sensors (3-8) are operatively connected. According to the invention, the voltage supply unit (9) comprises at least two supply benches (13-15) that can be switched independently from each other. The sensors (3-8) are grouped according to the function thereof and are then associated with one of the supply benches (13-15).