Abstract: Various systems and methods are described for operating an engine system having a sensor coupled to an exhaust gas recirculation system in a motor vehicle. One example method comprises during a first operating condition, directing at least some exhaust gas from an exhaust of the engine through the exhaust gas recirculation system and past the sensor to an intake of the engine and, during a second operating condition, directing at least some fresh air through the exhaust gas recirculation system and past the sensor.

Abstract: Various systems and methods are described for controlling operation of a motor vehicle based on a sensor. One example method comprises receiving sensed parameter data from the sensor, receiving calibration data from the sensor, and adjusting a vehicle operating parameter in response to the sensed parameter data and the calibration data.

Abstract: The systems and method described above in the present disclosure allow for regeneration of a diesel particulate filter while a vehicle is in stationary power take-off mode. Described is a method of: during select power take-off conditions, reducing an EGR rate responsive to an indication to regenerate a diesel particulate filter.

Abstract: Various systems and methods are described for detecting ammonia slip. In one example method, an exhaust system with two NOx sensors uses transient responses of the NOx sensors to allocate tailpipe NOx sensor output to NOx and NH3 levels therein. An ammonia slip detection counter with gains is included that determines a probability of NOx and NH3 based on the measured sensor activities that are further processed by a controller to adjust one or more parameters based on the allocation and changes of sensor output.

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: Various systems and methods are described for operating an engine system having a sensor coupled to an exhaust gas recirculation system in a motor vehicle. One example method comprises during a first operating condition, directing at least some exhaust gas from an exhaust of the engine through the exhaust gas recirculation system and past the sensor to an intake of the engine and, during a second operating condition, directing at least some fresh air through the exhaust gas recirculation system and past the sensor.

Abstract: A method of operating an internal combustion engine having a reductant delivery and storage system in an emission control system, comprising of correlating a change in a monitored operating condition with a refill event to determine whether a reductant-diluting substance has been added to the reductant storage system; and limiting vehicle operation based on the correlation.

Abstract: Methods and systems for controlling operation of exhaust of an engine including a particulate filter are described. One example method includes generating compressed air during engine operation, and storing the compressed air. The method further includes, during or after engine shutdown, pushing the compressed air through the particulate filter using a pressure of the compressed air.

Abstract: Modification of reductant (e.g., diesel exhaust fluid, DEF) tank location, for example during vehicle up-fitting may result in less than optimal operation of the DEF system due to inaccurate DEF system calibration. In one example approach, the above issue can be at least partially addressed by adjusting control system parameters for system control and diagnostics based on an input indicative of, or any modification to, the DEF tank location. In this way, DEF tank location flexibility is maintained, while also maintaining emission control and diagnostic accuracy.

Abstract: A system for improving operation of an engine having a particulate matter sensor is presented. The system may be used to improve engine operation during cold starts especially under conditions where water vapor or entrained water droplets are present in vehicle exhaust gases. In one embodiment, an engine controller that activates a heater of an exhaust gas sensor after an output of a particulate matter sensor exceeds a threshold value after an engine is started.

Abstract: Various systems and methods are described for operating an engine system having a sensor coupled to an exhaust gas recirculation system in a motor vehicle. One example method comprises during a first operating condition, directing at least some exhaust gas from an exhaust of the engine through the exhaust gas recirculation system and past the sensor to an intake of the engine and, during a second operating condition, directing at least some fresh air through the exhaust gas recirculation system and past the sensor.

Abstract: Various systems and methods are described for detecting ammonia slip. In one example method, an amount of exhaust gas recirculation is reduced when output from an exhaust gas sensor indicates an increase in nitrogen oxide above a threshold amount. When the sensor output increases above a second threshold while the exhaust gas recirculation is reduced, the sensor output is allocated to nitrogen oxide; and when the sensor output does not increase above a second threshold while the exhaust gas recirculation is reduced, the sensor output is allocated to ammonia.

Abstract: A method for controlling a particulate matter sensor heater is provided. The method includes operating the heater to burn-off soot accumulated on the sensor; and adjusting the heater level based on sensor output generated during the heater operation. In this way, improved heater control can be achieved using the sensor output already available.

Abstract: A method for operating a spark-ignition engine having a three-way catalyst and a particulate filter downstream thereof, comprising: oscillating an exhaust air-fuel ratio entering the particulate filter to generate air-fuel ratio oscillations downstream of the particulate filter, while increasing exhaust temperature; when the downstream oscillations are sufficiently dissipated, enleaning the exhaust air-fuel ratio entering the particulate filter; and reducing the enleanment when an exhaust operating parameter is beyond a threshold amount.

Abstract: A method to control a hybrid electric vehicle includes operating a compression ignition engine based on an engine-on request, and performing an exhaust aftertreatment procedure when a fraction of an engine-on time is greater than an aftertreatment condition threshold. A vehicle has a compression ignition engine with an exhaust aftertreatment system, and a controller. The controller is configured to: (i) operate the engine based on an engine-on request, and (ii) perform an exhaust aftertreatment procedure for the vehicle when an engine-on fraction for a designated time is greater than an aftertreatment condition threshold. A computer readable medium having stored data representing instructions executable by a controller to control a vehicle includes instructions for operating the engine based on an engine-on request, and instructions for performing an exhaust aftertreatment procedure for the vehicle when an engine-on time fraction is greater than an aftertreatment condition threshold.

Abstract: Methods systems and device for detecting humidity in air through use of an ammonia sensor included in the exhaust of an engine, such as a diesel engine are provided. In one example, a method for an engine having an exhaust with an ammonia sensor includes adjusting an operating parameter in response to ambient humidity, the ambient humidity based on a first ammonia sensor reading at a first exhaust air-fuel-ratio and a second ammonia sensor reading at a second exhaust air-fuel-ratio.

Abstract: A method for controlling a particulate matter sensor heater is provided. The method includes operating the heater to burn-off soot accumulated on the sensor; and adjusting the heater level based on sensor output generated during the heater operation. In this way, improved heater control can be achieved using the sensor output already available.

Abstract: Methods and systems for improving operation of an SCR are disclosed. In one example, engine hydrocarbon emissions are reduced and/or directed to bypass an SCR so that SCR efficiency can be increased. The methods and systems may reduce NOx emissions of a vehicle via improving SCR efficiency.

Abstract: Methods and systems for controlling operation of exhaust of an engine including a particulate filter are provided. One example method includes generating vacuum during engine operation, and storing the vacuum. The method further includes, during or after engine shutdown, drawing ambient air through the particulate filter via the vacuum.

Abstract: In one approach a method for operating an engine including a DPF is provided. The method includes adjusting a post fuel injection amount based on a rate of change of engine torque during DPF regeneration. As one example, the adjusting includes reducing the amount when the rate of change is positive, and increasing the amount when the rate of change is negative. Furthermore, the method may also include delivering exhaust gas to a turbocharger turbine, to an oxidation catalyst, and then a DPF, the adjusting of the post fuel injection further based on thermal inertia of the turbocharger.