Abstract: A dosing control system for an exhaust system of an engine includes: a tank containing a reductant solution having urea; an injector operable to inject the reductant solution into an exhaust flow upstream of an SCR apparatus; first and second NOx sensors disposed to sense NOx emissions in the exhaust flow upstream and downstream, respectively, of the SCR apparatus; and a control module. The control module is disposed in signal communication with the first and second NOx sensors and in operable communication with the injector, the control module being operable to set an original dosing level and decrease a dosing of the reductant solution injected by the injector based on a determination from signals received from the first and second NOx sensors that a reduction in a conversion efficiency of the SCR apparatus below a defined level of conversion efficiency has occurred.

Abstract: A method for diagnosing an Oxidation Catalyst (OC) device of an exhaust gas treatment system is provided. The method monitors a differential temperature across the OC device. The method determines whether the differential temperature reveals a temperature spike. The method determines that the OC device operates properly in response to determining that the differential temperature reveals a temperature spike.

Abstract: A diagnostic module for diagnosing a particulate matter sensor in a vehicle includes a sensor mode selection module, a heater power detector, and a protection tube diagnostic module. The sensor mode selection module selects a regeneration mode for the particulate matter sensor from among a plurality of operation modes. The regeneration mode regenerates the particulate matter sensor. The heater power detector determines a voltage output based on a voltage applied to the particulate matter sensor. The voltage output corresponds to operation of the particulate matter sensor in the selected mode. The protection tube diagnostic module performs a diagnostic of the particulate matter sensor. The protection tube diagnostic module selectively diagnoses a fault in the particulate matter sensor based on the voltage output determined during the regeneration mode and a regeneration power threshold.

Abstract: A method is disclosed for regulating an exhaust after-treatment (AT) system for a diesel engine. The method includes detecting the engine's cold start when the engine's exhaust gas flow directed into the AT system is at a temperature below a threshold value. The method also includes determining flow-rates of the engine's exhaust gas and its fuel supply. The method additionally includes determining a magnitude of exhaust gas energy using the determined exhaust gas flow-rates and the fuel supply over an elapsed time following the cold start. The method also includes integrating a detected temperature of the exhaust gas over the elapsed time and comparing the determined magnitude of exhaust gas energy with the integrated temperature. Furthermore, the method includes regulating operation of the AT system using the determined exhaust gas temperature when the determined magnitude of exhaust gas energy is within a predetermined value of the integrated exhaust gas temperature.

Abstract: A method for diagnosing an Oxidation Catalyst (OC) device of an exhaust gas treatment system is provided. The method monitors a differential temperature across the OC device. The method determines whether the differential temperature reveals a temperature spike. The method determines that the OC device operates properly in response to determining that the differential temperature reveals a temperature spike.

Abstract: A monitoring system for a single can oxidation catalyst (OC)/particulate filter (PF) member includes a controller including a first temperature sensor input configured to receive a first exhaust temperature upstream of an OC portion of the single can OC/PF member, a second temperature sensor input configured to receive a second exhaust temperature downstream of the first temperature. The controller is configured and disposed to calculate an exothermic capacity of the OC portion and determine washcoat deterioration of a PF portion of the single can OC/PF member based on the exothermic capacity of the OC portion.

Abstract: A method is disclosed for regulating an exhaust after-treatment (AT) system for a diesel engine. The method includes detecting the engine's cold start when the engine's exhaust gas flow directed into the AT system is at a temperature below a threshold value. The method also includes determining flow-rates of the engine's exhaust gas and its fuel supply. The method additionally includes determining a magnitude of exhaust gas energy using the determined exhaust gas flow-rates and the fuel supply over an elapsed time following the cold start. The method also includes integrating a detected temperature of the exhaust gas over the elapsed time and comparing the determined magnitude of exhaust gas energy with the integrated temperature. Furthermore, the method includes regulating operation of the AT system using the determined exhaust gas temperature when the determined magnitude of exhaust gas energy is within a predetermined value of the integrated exhaust gas temperature.

Abstract: A method is disclosed for controlling a diesel engine equipped with a diesel particulate filter (DPF). The method includes detecting steady state operation of the engine generating a first flow rate of particulate matter (PM) directed into the DPF. The method also includes, during the steady state operation, triggering exhaust gas recirculation to the engine and thereby directing a second PM flow rate that is greater than the first flow rate into the DPF. The method additionally includes detecting a PM flow rate exiting the DPF in response to the second PM flow rate directed into the DPF. The method also includes comparing the detected PM flow rate exiting the DPF with a PM flow rate threshold. Furthermore, the method includes regulating injection of fuel to regenerate the DPF, if the detected PM flow rate exiting the DPF is greater than the PM flow rate threshold.

Abstract: A method is disclosed for regulating an exhaust after-treatment (AT) system having a diesel particulate filter (DPF) in fluid communication with a diesel engine. The method includes detecting operation of the diesel engine during which the engine generates a flow rate of particulate matter (PM) directed into the DPF. The method also includes detecting a flow rate of PM exiting the DPF in response to the flow rate of PM directed into the DPF. The method additionally includes tracking the detected flow rate alongside a predicted PM flow rate for monitoring and comparison thereof. The method also includes pausing in time the tracking of the predicted flow rate, if the detected flow rate has experienced a decline. Furthermore, the method includes resuming tracking the predicted flow rate when the detected flow rate returns to a value before the decline and using such value to regulate operation of the AT system.

Abstract: A diagnostic module for diagnosing a particulate matter sensor in a vehicle includes a sensor mode selection module, a heater power detector, and a protection tube diagnostic module. The sensor mode selection module selects a regeneration mode for the particulate matter sensor from among a plurality of operation modes. The regeneration mode regenerates the particulate matter sensor. The heater power detector determines a voltage output based on a voltage applied to the particulate matter sensor. The voltage output corresponds to operation of the particulate matter sensor in the selected mode. The protection tube diagnostic module performs a diagnostic of the particulate matter sensor. The protection tube diagnostic module selectively diagnoses a fault in the particulate matter sensor based on the voltage output determined during the regeneration mode and a regeneration power threshold.

Abstract: A method of increasing a weighting factor of an exponentially weighted moving averaging (“EWMA”) filter is provided. The method includes monitoring a data stream containing raw data values, and determining an EWMA value based on the data stream by an electronic control module. The method includes determining if the EWMA value is between a predetermined maximum fault threshold value and a predetermined minimum fault threshold value. The method includes increasing the weighting factor of the EWMA filter to more heavily weigh incoming raw data values of the data stream based on the difference between the first raw data value and a previously calculated filtered value exceeding the calibration value.

Abstract: A method of estimating a mass flow rate of nitrogen oxides in exhaust gas includes sensing a mass flow rate of a flow of exhaust gas from the engine. A nitrogen oxides base concentration for when the engine is operating at a reference state is defined, and a nitrogen oxides ratio for a current operating state of the internal combustion engine is calculated. The mass flow rate of the flow of exhaust gas, the nitrogen oxides base concentration, and the nitrogen oxides ratio for the current operating state of the engine are multiplied together to define an estimated value of the current mass flow rate of nitrogen oxides in the flow of exhaust gas from the engine. The estimated value of the mass flow rate of nitrogen oxides may be compared to the output from a nitrogen oxides sensor to determine proper functionality of the nitrogen oxides sensor.

Abstract: A method of estimating a mass flow rate of nitrogen oxides in exhaust gas includes sensing a mass flow rate of a flow of exhaust gas from the engine. A nitrogen oxides base concentration for when the engine is operating at a reference state is defined, and a nitrogen oxides ratio for a current operating state of the internal combustion engine is calculated. The mass flow rate of the flow of exhaust gas, the nitrogen oxides base concentration, and the nitrogen oxides ratio for the current operating state of the engine are multiplied together to define an estimated value of the current mass flow rate of nitrogen oxides in the flow of exhaust gas from the engine. The estimated value of the mass flow rate of nitrogen oxides may be compared to the output from a nitrogen oxides sensor to determine proper functionality of the nitrogen oxides sensor.

Abstract: A method of monitoring an engine coolant system includes modeling the total energy stored within an engine coolant. If an actual temperature of the engine coolant is below a minimum target temperature, the modeled total energy stored within the energy coolant is compared to a maximum stored energy limit to determine if sufficient energy exists within the engine coolant to heat the engine coolant to a temperature equal to or greater than the minimum target temperature. The engine coolant system fails the diagnostic check when the modeled total energy stored within the energy coolant is greater than the maximum stored energy limit, and the minimum target temperature has not been reached.

Abstract: An internal combustion engine includes a particulate filter that is configured to treat exhaust gas. A method for monitoring the particulate filter includes employing a soot sensor to monitor the exhaust gas downstream of the particulate filter. A fault is detected in the particulate filter when accumulated soot mass indicated by the soot sensor exceeds a soot mass threshold over a course of engine operation between a first regeneration event and a second regeneration event of the particulate filter. A control module associated with operation of the internal combustion engine is notified of the fault.

Abstract: A method for particulate filter performance monitoring in an exhaust gas treatment system is provided. The method includes monitoring a current received from a soot sensor in the exhaust gas treatment system and comparing the current to a soot sensor current threshold. Based on determining that the current is greater than or equal to the soot sensor current threshold, an accumulated engine out soot value is compared to an accumulated engine out soot threshold. A particulate filter fault is set based on determining that the accumulated engine out soot value is less than the accumulated engine out soot threshold. A monitoring system and an exhaust gas treatment system of an engine are also provided.

Abstract: A method is disclosed for controlling regeneration in a diesel engine after-treatment system having a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF). The method includes injecting an amount of fuel into an exhaust gas flow upstream of the DOC to superheat the gas flow and assessing a rate of the warm-up of the DOC. The method also includes determining, in response to the assessed rate of the warm-up of the DOC, an amount of catalyst substance available in the DOC for catalyzing the exhaust gas flow. The method additionally includes reducing the amount of fuel injected into the DOC such that the determined available amount of catalyst substance is utilized in the DOC for catalyzing the exhaust gas flow and a predetermined amount of fuel is permitted to slip through the DOC to maintain regeneration temperature in the DPF. A system and a vehicle are also disclosed.

Abstract: A dosing control system for an exhaust system includes: a reductant fluid tank operable to contain a reductant solution comprising urea; an injector disposed in operable communication between a reductant tank and an SCR apparatus, the injector being operable to inject the reductant solution from the reductant tank into a flow of exhaust upstream of the SCR apparatus; a urea quality sensor (UQS) configured and disposed to sense a concentration of the urea in the reductant solution; and, a control module disposed in signal communication with the UQS and in operable communication with the injector, the control module being operable to adjust a dosing of the reductant solution injected by the injector based on a concentration of the urea in the reductant solution.

Abstract: A method for assessing NO2 generation efficiency in a diesel engine after-treatment (AT) system having a diesel oxidation catalyst (DOC) downstream of the engine generating the NO2 and a selective catalytic reduction (SCR) catalyst downstream of the DOC converting NOX with the aid of the NO2. Engine exhaust gas flow is passed into the AT system and a reductant is injected into the gas flow between the DOC and the SCR catalyst. SCR inlet gas flow temperature is monitored during transient engine operation and DOC inlet and SCR catalyst outlet NOX concentrations are detected when the SCR catalyst inlet gas flow temperature is in a predetermined range. SCR catalyst NOX conversion efficiency is determined using the detected DOC inlet and SCR catalyst outlet concentrations of NOX. Additionally, whether the NO2 generation efficiency is at or above threshold efficiency is assessed by comparing the determined and threshold NOX conversion efficiencies.

Abstract: A dosing control system for an exhaust system includes: a reductant fluid tank operable to contain a reductant solution comprising urea; an injector disposed in operable communication between a reductant tank and an SCR apparatus, the injector being operable to inject the reductant solution from the reductant tank into a flow of exhaust upstream of the SCR apparatus; a urea quality sensor (UQS) configured and disposed to sense a concentration of the urea in the reductant solution; and, a control module disposed in signal communication with the UQS and in operable communication with the injector, the control module being operable to adjust a dosing of the reductant solution injected by the injector based on a concentration of the urea in the reductant solution.