Systems and methods for diagnosing an exhaust aftertreatment system are provided. A method includes: receiving, by a controller and for each sensor of a plurality of sensors, one or more respective degradation level indicators indicative of one or more failure levels of the sensor, each of the one or more degradation level indicators determined using a corresponding performance parameter; receiving, by the controller and for each sensor of the plurality of sensors, one or more diagnosis threshold values; determining, by the controller, a multipoint diagnosis threshold value using the one or more diagnosis threshold values associated with the plurality of sensors; detecting, by the controller, an operational state of the aftertreatment system by comparing a performance value of the aftertreatment system to the multipoint diagnosis threshold value; and causing, by the controller, an indication of the operational state of the aftertreatment system to be displayed on a display device.

A coolant control system of a vehicle includes a coolant pump that pumps coolant to a second radiator that is different than a first radiator that receives coolant from an engine of the vehicle. A diesel exhaust fluid (DEF) injector injects a DEF into an exhaust system and receives coolant output from the second radiator. A fuel heat exchanger transfers heat between coolant and fuel flowing therethrough. An engine control module is configured to determine a temperature of the DEF injector, control a duty cycle of the coolant pump, determine a vaporized condition of the coolant based on a DEF injector temperature, optionally further, in response to determining a vaporized condition of the coolant, implement a vapor purge by oscillating the duty cycle of the coolant pump, and optionally further identify a low-coolant condition of the coolant control system based on the vapor purges implemented during a time period.

An injector is provided to inject an aqueous urea solution into an exhaust line. The injector comprises a single fluid inlet, an injection passage, fluidly connecting the inlet to the injection port, and a shut-off device for the injection port. The shut-off device further comprises an actuator that is configured to selectively move a shutter between open and closed positions. A cooling passage is fluidly connected to the injection passage and is configured to cool the actuator. A fluid pressure regulator is interposed in the cooling passage.

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 system for controlling reductant spray momentum for a target spray distribution includes an exhaust system having an exhaust conduit with exhaust flowing therethrough, a reductant injection system for injecting reductant into the exhaust flowing through the exhaust system based on one or more injection parameters, a reductant supply system for supplying reductant to the reductant injection system based on one or more supply parameters, and a controller. The controller is configured to access current vehicle, engine, exhaust, or reductant condition parameters, determine one or more control parameters based on a control model and the accessed current vehicle, engine, exhaust, or reductant condition parameters, and modify a value of the one or more injection parameters or the one or more supply parameters to control the reductant spray.

An exhaust gas after-treatment unit for an internal combustion engine, particularly for a motor vehicle, includes a first selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine can flow and at least one particle filter for retaining the soot particles from the exhaust gas. The particle filter, which is located downstream from the first SCR catalytic converter, is equipped with a heavy metal and precious metal free catalyzing coating which oxidizes the soot particles retained by the particle filter, where downstream from the particle filter there is a second SCR catalytic converter through which the exhaust gas can flow.

Technical solutions are described for an emissions control system for controlling a selective catalytic reduction (SCR) device of an exhaust system of an internal combustion engine. An example computer-implemented method includes governing a reductant dosing in the SCR device. For example, governing the dosing includes computing a reductant dosing rate based on a chemical model of the SCR device. Further, the governing includes determining a temperature modulation factor based on inlet temperature of exhaust gas input for the SCR. The method further includes adjusting the reductant dosing rate by scaling the reductant dosing rate by the temperature modulation factor. The method further includes causing an amount of reductant to be injected into an SCR catalyst according to the adjusted reductant dosing rate.

The present invention relates to a method for determining when to correct supply of additive to an exhaust gas stream resulting from combustion in at least one combustion chamber, wherein the additive is arranged for reduction of at least one substance resulting from said combustion by supplying the additive to an exhaust gas stream resulting from said combustion. The quantity of additive being supplied is subjectable to correction, and a sensor is subjected to the exhaust gas stream and arranged to measure occurrence of said at least one substance. The method comprises: by means of sensor signals from said sensor, determining a level of occurrence of said first substance in said exhaust gas stream, and determining when to correct said supply of additive on the basis of said occurrence of said first substance in said exhaust gas stream.

Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injection into the exhaust gas. Controlling the reductant injection includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductant to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injector to inject the computed amount of reductant.

An exhaust purification system is provided with a NOx-occlusion-reduction-type catalyst 32 that occludes NOx in exhaust when the exhaust is in a lean state and reduces and purifies the occluded NOx when the exhaust is in a rich state, and a NOx purge rich control unit 140 for reducing and purifying NOx occluded in the NOx-occlusion-reduction-type catalyst 32 by putting the exhaust into the rich state by repetitively performing fuel injection control of at least one of post injection and exhaust pipe injection at a predetermined interval.