A computer-implemented method for determining whether a reductant (e.g. urea) injector is clogged is provided. The method includes receiving data indicative of an injector duty cycle and a pump duty cycle. Using a trained machine learning module, at least a first value is calculated, indicative of a probability of the injector being clogged. The method further includes providing, based on the first value, an indication of whether the reductant injector is clogged. A device for providing the indication using the method, a computer program, a reductant injector system, and e.g. a combustion engine including such a reductant injector system are also provided.

One or more techniques and/or systems are disclosed for providing localized heating within an engine exhaust aftertreatment system. The localized heating includes DEF injector nozzle heating with a DEF dispensing system having a DEF fluid supply and a DEF injector fluidly coupled to the DEF fluid supply. The DEF injector includes a DEF injector nozzle. The DEF dispensing system further includes a DEF heater positioned in proximity to the DEF injector nozzle. The DEF heater is configured to locally heat an area surrounding the DEF injector nozzle.

A selective catalytic reduction system control system (10) and method of its use include an ammonia (“NH.sub.3”) slip sensor (13) located within an interior space (27) of an exhaust stack (15) of a selective catalytic reactor (31), toward an inlet end (25) of the stack (15); a housing (17) located within the interior space of the exhaust stack; the housing including face panels 19; a nitrogen oxides (“NOx”) sensor (11) contained within an interior space (29) defined by the face panels of the housing, at least two of the face panels (19.sub.I, 19.sub.O) containing an oxidation catalyst; and a dosing controller (59) in communication with the NH.sub.3 and NOx sensors, the dosing controller including a microprocessor with dosing logic embedded thereon. The housing with oxidation catalyst acts as a linear box, isolating the NOx sensor from NH.sub.3 slip, linearizing the NOx sensor signal.

An arrangement for testing or treating a dosing valve of a dosing device of a dosing system in a vehicle includes connecting an electrical test drive to an electrical connector of the dosing device and connecting a dosing tester to a liquid inlet of the dosing device. Thereafter, an outlet valve of the dosing tester is opened to provide liquid under pressure to a liquid inlet of the dosing device. After a first given time, the electrical test drive provides pulses to repeatedly attempt to open the dosing valve. Upon a reduction in liquid level of liquid within the dosing tester in response to opening of the dosing valve, an operator closes the outlet valve of the dosing tester to discontinue the treatment.

Operating an engine exhaust aftertreatment system includes receiving fluid pressure data of a reductant pump, determining a pump operating state, and comparing a pump health parameter to a prognostic pump failure criterion based upon the determining a pump operating state. Operating an engine exhaust aftertreatment system further includes outputting a pump health alert based upon a difference between the pump health parameter and the prognostic pump failure criterion. Related control logic is also disclosed.

A selective catalytic reduction system includes a reducing agent injection module installed in an exhaust pipe through which an exhaust gas is discharged from an engine and configured to inject a reducing agent into the exhaust pipe, a temperature calculator configured to calculate a temperature of the reducing agent injection module using temperature-related information of the reducing agent injection module, and a temperature controller configured to control to increase a reducing agent injection amount of the reducing agent injection module when the calculated temperature.

An aftertreatment system comprises an aftertreatment component structured to decompose constituents of an exhaust gas produced by an engine. A reductant insertion assembly is fluidly coupled to the aftertreatment component and configured to insert a reductant therein. A controller is operatively coupled to the reductant insertion assembly and configured to instruct the reductant insertion assembly to insert the reductant into the aftertreatment component for a first insertion time between first time intervals. The controller determines an operating condition of the engine, and determines if the operating condition satisfies a predetermined condition. In response to the predetermined condition being satisfied, the controller instructs the reductant insertion assembly to insert the reductant into the aftertreatment component for a second insertion time between second time intervals. The second insertion time is longer than the first insertion time.

The present invention discloses methods and devices for controlling a heated mixer, situated downstream of a Urea-Water Solution (UWS) injector, to reduce NOx emission in an exhaust system from combustion engines, wherein the exhaust system has a Selective Catalytic Reduction (SCR) catalyst situated downstream of the UWS injector and the heated mixer, Methods include: determining a NOx reduction efficiency of the SCR catalyst; evaluating at least one reductant Uniformity Index (UI) based on operating parameters of the exhaust system and a mixer power calculation map; and modifying a mixer temperature of the heated mixer by regulating power to the heated mixer based on at least one reductant UI in order to improve at least one reductant UI and/or improve the NOx reduction efficiency. Alternatively, the method further includes: detecting at least one potential improvement of at least one UI and/or the NOx reduction efficiency based on an increased ammonia mass.

A method of adaptively sampling data to determine the start of injection in a solenoid actuated valve of a fluid injector includes, in an operating cycle or portion thereof of the valve, sampling the signal of current through a solenoid of the valve at sampling points having a pre-defined interval therebetween. At each sampling point, determining the value of the first derivative of current and detecting the sampling point at which the first derivative achieves a maximum as the start of injection. Values of the first derivative of the sampling points immediately preceding and immediately following the start of injection are determined. In a subsequent operating cycle, synchronisation of sampling is altered to shift sampling times depending on the values of the first derivative of the sampling points immediately preceding and immediately following the start of injection.

A method for operating a dosing device for metering an additive to an exhaust-gas treatment device includes determining a dosing amount of additive required by the exhaust-gas treatment device in step a). Subsequently, in step b), an operating mode for the dosing device is determined by carrying out at least steps b.1) and b.2). In step b.1), at least one characteristic operating value of at least one component of the dosing device is provided being definitive of a degree of aging of the dosing device. In step b.2), an operating mode for the dosing device is set in dependence on the characteristic operating value from step b.1). In step c), the dosing device is operated with the set operating mode so that the dosing amount required in step a) is supplied to the exhaust-gas treatment device. A motor vehicle having a dosing device is also provided.