An exhaust aftertreatment system includes a particulate filter element and a particulate matter sensor that is disposed to monitor the exhaust gas feedstream downstream of the particulate filter element. A method for monitoring the exhaust gas feedstream includes determining a temperature associated with the particulate matter sensor and monitoring engine operation and the exhaust aftertreatment system. A magnitude of ammonia is determined in the exhaust gas feedstream proximal to the particulate matter sensor based upon the monitoring of the engine operation and the exhaust aftertreatment system. An initial reading is determined from the particulate matter sensor and is adjusted based upon the magnitude of ammonia in the exhaust gas feedstream proximal to the particulate matter sensor and the temperature of the particulate matter sensor. A magnitude of particulate matter in the exhaust gas feedstream is determined based upon the adjusted initial reading from the particulate matter sensor.

A diagnostic system for an internal combustion engine is disclosed. The diagnostic system may include an electronic control unit. The electronic control unit may determine whether a predetermined condition is satisfied. The predetermined condition may be a condition under which an amount of particulate matter that separates from a filter is larger than or equal to a predetermined separation amount as a urea water-originated deposit once accumulated in the filter separates in gaseous form. When the electronic control unit determines that the predetermined condition is satisfied, the electronic control unit may not execute a diagnosis of a malfunction in the filter based on a filter differential pressure until a predetermined period elapses from the point in time at which it is determined that the predetermined condition is satisfied.

A system for diagnosing engine braking performance of an engine comprising a plurality of cylinders comprises an exhaust manifold pressure sensor configured to detect an exhaust manifold pressure corresponding to exhaust gas emitted from a plurality of cylinders. A controller is configured to determine an exhaust manifold pressure value corresponding to at least one cylinder of the plurality of cylinders that is being used for engine braking, from an exhaust manifold pressure sensor signal received from the exhaust manifold pressure sensor. The controller is also configured to determine an engine braking value based on the exhaust manifold pressure value.

A method and a device for determining the injection quantity or the injection rate of a fluid which is transported to an injector through a hydraulic line and is injected into a reaction space by the injector. The fluid pressure in the hydraulic line is measured by a pressure sensor, the fluid pressure at the injector is determined using the pressure measured by the pressure sensor and a stored transmission function of the hydraulic line, and the injection quantity or the injection rate of the fluid injected by the injector is determined using the fluid pressure determined at the injector.

Disclosed is a method for diagnosing functionality of dosing units of a fluid dosing system comprising at least two dosing units, a tank unit for holding a fluid, and a pump unit for pressurizing the fluid for the dosing units. The method comprises determining a first hydraulic stiffness value on the basis of first pressure variations and determining a second hydraulic stiffness value on the basis of said second pressure variations. The first hydraulic stiffness value and second hydraulic stiffness value are compared. In a case where the first hydraulic stiffness value and second hydraulic stiffness value differ to a certain extent, concluding that malfunction of at least one of said dosing units is at hand, and in a case where the first hydraulic stiffness value and the second hydraulic stiffness value do not differ to said certain extent, concluding that the first and second dosing units function as intended.

Provided is a pre-chamber type diesel engine wherein the fuel system is not complicated, regardless of whether a regeneration function is provided. An injector is employed, which is able to inject fuel at a given timing by means of an electrical signal from a controller, and when a prescribed amount of particles have been trapped in a particle collection filter the injector carries out an additional fuel injection during the expansion stroke of a piston.

A system and method that forwards information concerning the condition of the particulate filter (14) in each fleet vehicle to a remote station (56). This information is sorted (114) and displayed (62) to a human operator, who then makes a decision regarding particulate filter maintenance, on a fleet wide basis (116). The human operator may select a set of vehicles to undergo filter regeneration during a particular time slot, at a facility with a limited capacity to perform filter regeneration during any particular time slot. Typically, this will be overnight, for example for a metropolitan bus service that is busy during the day but has greatly reduced or nonexistent service at nighttime.

Provided is a diesel engine capable of regenerating a DPF even during no-load and/or light-load operation. In a DPF regeneration process, opening-degree reduction control S2 for an exhaust-air throttle valve is performed after a start condition S1 of the regeneration process of the DPF in which PM is deposited is satisfied. When exhaust air reaches a temperature equal to or higher than a predetermined after-injection permissible temperature TA, after-injection control is subsequently started S5. Post-injection control is started S7 after the exhaust air reaches a temperature equal to or higher than a predetermined post-injection permissible temperature TP by combustion of after-injection fuel. The PM deposited in the DPF is incinerated by the exhaust air increased in temperature by catalytic combustion of post-injection fuel in a valve downstream-side DOC.

The exhaust purification system of an internal combustion engine includes a filter trapping particulate matter in exhaust gas flowing through an exhaust passage of the internal combustion engine and supporting a three-way catalyst, and a filter regeneration part configured to perform regeneration processing for oxidizing and removing particulate matter deposited on the filter when predetermined conditions are satisfied. The filter regeneration part is configured to increase an NO concentration in exhaust gas flowing into the filter when the predetermined conditions are satisfied compared to when the predetermined conditions are not satisfied.

A system and method for controlling an aftertreatment assembly includes a diesel oxidation catalyst (DOC) device configured to receive an exhaust gas. One or more sensors are configured to obtain respective sensor data relative to the exhaust gas and DOC device. A controller is in communication with the sensors and configured to obtain respective sensor data relative to the exhaust gas. The controller is configured to determine if one or more enabling conditions are met, including reaching a predefined temperature range in the DOC device. A rich event is induced targeting a predetermined range of a lambda value for a predefined maximum time duration. When the rich event has ended, an exotherm index is obtained for an observation window immediately after the rich event. The controller is configured to control operation of the aftertreatment assembly based at least partially on the exotherm index.