Abstract: Controlling exhaust after-treatment in a heavy-duty motor vehicle includes operating a diesel engine of a heavy-duty truck such that the diesel engine generates an exhaust gas flow that enters an exhaust after-treatment system of the heavy-duty truck, the exhaust after-treatment system including a selective catalytic reduction system, measuring a level of NOx gases in the exhaust gas flow downstream of the selective catalytic reduction system, and controlling a diesel exhaust fluid injector upstream of the selective catalytic reduction system to inject diesel exhaust fluid into the exhaust gas flow upstream of the selective catalytic reduction system at an injection rate that is based on the measured level of NOx gases.

Abstract: The present disclosure relates to systems and methods of automatically distributing powertrain demand between tandem drive axles in a tandem drive axle system for balanced tire wear between the tandem drive axles. Examples described herein analyze input signals collected from various vehicle sensors about operating conditions of the front and back tandem drive axles, and automatically bias a distribution of torque demand between the front and back tandem drive axles to correct for asymmetric wear based on known normal wear of the tires under like operating conditions.

Abstract: A lean-burn internal combustion engine and an exhaust aftertreatment system having an oxidation catalyst are described. A controller determines a fueling rate and a mass flowrate of the exhaust gas feedstream. An inlet temperature of the exhaust gas feedstream upstream of the oxidation catalyst is determined via the first temperature sensor, and an in-use outlet temperature of the exhaust gas feedstream is determined downstream of the oxidation catalyst via the second temperature sensor. An expected outlet temperature from the oxidation catalyst is determined based upon the inlet temperature, the fueling rate, and the mass flowrate of the exhaust gas feedstream. The oxidation catalyst is evaluated based upon the expected outlet temperature and the in-use outlet temperature.

Abstract: A method includes detecting a diesel engine runaway event in a diesel engine and, in response to detecting the diesel engine runaway event, deactivating all cylinders in the diesel engine such that no combustion occurs in any cylinders of the diesel engine and no cylinders of the diesel engine produce power, wherein deactivating the cylinders of the diesel engine includes mechanically decoupling a camshaft of the diesel engine from inlet valves of the cylinders of the diesel engine, and wherein deactivating cylinders of the diesel engine prevents flow of air from an intake manifold into combustion chambers of the cylinders.

Abstract: A heavy duty truck includes a diesel engine that generates an exhaust gas flow and an exhaust after-treatment system for treatment of the exhaust gas flow. The exhaust after-treatment system includes at least one temperature sensor at an underbody SCR system within the exhaust after-treatment system and a DEF injector upstream of a close-coupled SCR system within the exhaust after-treatment system. The DEF injector is operated to inject DEF into the exhaust gas flow at a rate that varies as a function of a temperature measured by the temperature sensor.

Abstract: A heavy duty truck includes a diesel engine that generates an exhaust gas flow and an exhaust after-treatment system for treatment of the exhaust gas flow. The exhaust after-treatment system includes at least one heater and at least one selective catalytic reduction system downstream of the heater. The heater is operated to inject supplemental heat energy into the exhaust gas flow at a rate based on a difference between a target rate of heat energy in the exhaust gas flow at an inlet to the selective catalytic reduction system and a rate of heat energy supplied to the exhaust gas flow from the diesel engine.

Abstract: A method for starting a vehicle's engine includes: causing a crankshaft of the engine to begin to rotate and to rotate through a first plurality of rotations; and causing, for each combustion chamber of at least one combustion chamber of the engine, an exhaust valve of the combustion chamber to remain in an opened position while the crankshaft rotates through the first plurality of rotations and prior to fuel being injected into the combustion chamber.

Abstract: Systems and methods for modulating power provided to a heating element of a vehicle exhaust system is provided. One system includes a controller controlling a switch, and an alternator having a first field terminal input, wherein the first field terminal input is connected to the switch. The system further includes a heating element connected to at least an output of the alternator. The controller is configured to determine a power demand for the electric heating element and modulate the first field terminal input to cause the alternator to provide power to the heating element according to the power demand.

Abstract: A heavy-duty truck has a diesel engine, an exhaust after-treatment system, and an engine control unit. The exhaust after-treatment system includes a close-coupled selective catalytic reduction system and an underbody selective catalytic reduction system, a first NOx sensor upstream of the close-coupled selective catalytic reduction system, a second NOx sensor between the two selective catalytic reduction systems, and a third NOx sensor downstream of the underbody selective catalytic reduction system. The engine control unit may perform methods allowing intrusive diagnostics to be performed on exhaust gas NOx sensors using the selective catalytic reduction systems during normal operation of the heavy-duty truck.

Abstract: Controlling exhaust after-treatment in a heavy-duty motor vehicle includes operating a diesel engine of a heavy-duty truck such that the diesel engine generates an exhaust gas flow that enters an exhaust after-treatment system of the heavy-duty truck, the exhaust after-treatment system including a selective catalytic reduction system, measuring a level of NOx gases in the exhaust gas flow downstream of the selective catalytic reduction system, and controlling a diesel exhaust fluid injector upstream of the selective catalytic reduction system to inject diesel exhaust fluid into the exhaust gas flow upstream of the selective catalytic reduction system at an injection rate that is based on the measured level of NOx gases.

Abstract: A lean-burn internal combustion engine and an exhaust aftertreatment system having an oxidation catalyst are described. A controller determines a fueling rate and a mass flowrate of the exhaust gas feedstream. An inlet temperature of the exhaust gas feedstream upstream of the oxidation catalyst is determined via the first temperature sensor, and an in-use outlet temperature of the exhaust gas feedstream is determined downstream of the oxidation catalyst via the second temperature sensor. An expected outlet temperature from the oxidation catalyst is determined based upon the inlet temperature, the fueling rate, and the mass flowrate of the exhaust gas feedstream. The oxidation catalyst is evaluated based upon the expected outlet temperature and the in-use outlet temperature.

Abstract: Dynamic throttle pedal filtering of a vehicle is provided. An automated throttle filtering system may be included in the vehicle that may operate to filter throttle pedal input based on detection of a rough driving surface. The rough driving surface detection may be based on an evaluation of wheel speed signals or an indication of traction loss. The throttle pedal input may be filtered corresponding to rough driving surface magnitude values determined based on the wheel speed signals. For example, filtered torque demand values may be determined based on the rough driving surface magnitude values and included in a torque demand request communicated to the vehicle's powertrain system. The resulting torque output may modulate an undesirable oscillating torque demand that may be generated in relation to operation of the vehicle on a rough driving surface.

Abstract: The present disclosure describes methods for evaluating NOx conversion efficiency of a close coupled SCR unit of an EAS including the close coupled SCR unit and a downstream SCR unit. The determined NOx conversion efficiency of the close coupled SCR unit is used to diagnose the close coupled SCR unit and or EAS and to control operation parameters of the EAS and/or internal combustion engine operably connected to the EAS.

Abstract: A lean-burn internal combustion engine and an exhaust aftertreatment system having an oxidation catalyst are described. A controller determines a fueling rate and a mass flowrate of the exhaust gas feedstream. An inlet temperature of the exhaust gas feedstream upstream of the oxidation catalyst is determined via the first temperature sensor, and an in-use outlet temperature of the exhaust gas feedstream is determined downstream of the oxidation catalyst via the second temperature sensor. An expected outlet temperature from the oxidation catalyst is determined based upon the inlet temperature, the fueling rate, and the mass flowrate of the exhaust gas feedstream. The oxidation catalyst is evaluated based upon the expected outlet temperature and the in-use outlet temperature.

Abstract: The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

Abstract: A heavy duty truck includes a diesel engine that generates an exhaust gas flow and an exhaust after-treatment system for treatment of the exhaust gas flow. The exhaust after-treatment system includes at least one heater and at least one selective catalytic reduction system downstream of the heater. The heater is operated to inject supplemental heat energy into the exhaust gas flow at a rate based on a difference between a target rate of heat energy in the exhaust gas flow at an inlet to the selective catalytic reduction system and a rate of heat energy supplied to the exhaust gas flow from the diesel engine.

Abstract: A heavy duty truck includes a diesel engine that generates an exhaust gas flow and an exhaust after-treatment system for treatment of the exhaust gas flow. The exhaust after-treatment system includes at least one temperature sensor at an underbody SCR system within the exhaust after-treatment system and a DEF injector upstream of a close-coupled SCR system within the exhaust after-treatment system. The DEF injector is operated to inject DEF into the exhaust gas flow at a rate that varies as a function of a temperature measured by the temperature sensor.

Abstract: A heavy-duty truck has a diesel engine, an exhaust after-treatment system, and an engine control unit. The exhaust after-treatment system includes a close-coupled selective catalytic reduction system and an underbody selective catalytic reduction system, a first NOx sensor upstream of the close-coupled selective catalytic reduction system, a second NOx sensor between the two selective catalytic reduction systems, and a third NOx sensor downstream of the underbody selective catalytic reduction system. The engine control unit may perform methods allowing intrusive diagnostics to be performed on exhaust gas NOx sensors using the selective catalytic reduction systems during normal operation of the heavy-duty truck.

Abstract: Controlling exhaust after-treatment in a heavy-duty motor vehicle includes operating a diesel engine of a heavy-duty truck such that the diesel engine generates an exhaust gas flow that enters an exhaust after-treatment system of the heavy-duty truck, the exhaust after-treatment system including a selective catalytic reduction system, measuring a level of NOx gases in the exhaust gas flow downstream of the selective catalytic reduction system, and controlling a diesel exhaust fluid injector upstream of the selective catalytic reduction system to inject diesel exhaust fluid into the exhaust gas flow upstream of the selective catalytic reduction system at an injection rate that is based on the measured level of NOx gases.

Abstract: Controlling exhaust after-treatment in a heavy-duty motor vehicle includes operating a diesel engine of a heavy-duty truck such that the diesel engine generates an exhaust gas flow that enters an exhaust after-treatment system of the heavy-duty truck, the exhaust after-treatment system including a selective catalytic reduction system, measuring a level of NOx gases in the exhaust gas flow downstream of the selective catalytic reduction system, and controlling a diesel exhaust fluid injector upstream of the selective catalytic reduction system to inject diesel exhaust fluid into the exhaust gas flow upstream of the selective catalytic reduction system at an injection rate that is based on the measured level of NOx gases.