Methods and systems are provided to monitor a quantity relating to particulate mass M in at least one exhaust pipe arranged downstream of a combustion engine. A first determination device determines a reduction of a pressure difference dP over at least one or several particulate filters, arranged downstream of the combustion engine. This reduction is related to a pressure difference dP.sub.ref over one or more corresponding reference particulate filters. A second determination device determines a quantity related to the particulate mass M, based on the determined reduction of the pressure difference dP and a predetermined correlation between the reduction and the quantity related to the particulate mass M, so that use of soot sensors in the exhaust pipe may be avoided. A comparison device compares the quantity with a defined threshold value M.sub.th and a providing device provides indications related to the comparison.

A method and system for regenerating a soot particle filter of an internal combustion engine is disclosed. The engine control unit determines a pressure difference from a differential pressure signal received from a differential pressure sensor, which pressure difference is present between an exhaust gas inlet and an exhaust gas outlet of the soot particle filter. The method compares the pressure difference to a pressure difference threshold value and operates the combustion engine in a regeneration operating profile if the determined pressure difference is smaller than the pressure difference threshold value. If the determined pressure difference is greater, a differential pressure correction device is connected between the differential pressure sensor and the engine control unit and a differential pressure simulation signal is generated by the differential pressure correction device and transmitted to the engine control unit to operate the internal combustion engine in the regeneration operating profile.

An engine diagnostic tool includes a diagnostic engine calibration module structured to include a plurality of diagnostic processes for operating an internal combustion engine system of an immobilized vehicle. One or more of the plurality of diagnostic processes are structured to be an intrusive diagnostic process for the internal combustion engine system, wherein the intrusive diagnostic process causes the internal combustion engine system to operate outside of one or more calibration parameters. The diagnostic engine module is further structured to control the order and timing of each diagnostic process in the plurality of diagnostic processes.

Methods and systems for estimating an amount of residual or retained fuel that remains in a cylinder from a first cycle of the cylinder to a second cycle of the cylinder are described. In one example, the amount of residual fuel is estimated in response to a temperature of an oxidation catalyst. The retained fuel amount may then be the basis for adjusting fuel injection amounts during the second cycle of the cylinder.

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.

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.

A method includes calculating whether a quantity of the PMs accumulated in a PF is at or above a risk level at which damage to the PF is caused when regenerating the PF, calculating a driving condition index by accumulating a weighting factor for a driving condition under which there is a likelihood of causing the damage to the PF, when the amount of accumulated PMs is at or above the risk level; calculating a temperature index in accordance with a temperature of the PF and a PM index in accordance with the quantity of the accumulated PMs when the quantity of the accumulated PMs is at or above the risk level; calculating a degradation condition index considering the driving condition index, the temperature of the PF, and the quantity of accumulated PMs; and changing a regeneration period of the PF according to the degradation condition index.

A method for the diagnosis of an air supply circuit supplying air to a burner of an exhaust gas after-treatment system for an exhaust system of an internal combustion engine, wherein the air supply circuit is provided with a pumping device housed along a first duct adjusted by a shut-off valve. The method entails housing a first pressure sensor along the first duct interposed between the pumping device and the burner; housing a second pressure sensor along a second duct out of the burner; acquiring the pressure signals detected by said first and second pressure sensors; and diagnosing faults and/or malfunctions in the air supply circuit depending on the pressure signals detected by said first and second pressure sensors.

A method for controlling a filtering efficiency of a filter including a filtering area between an inflow area and an outflow area. Determining a present exhaust mass flow into the filter. Determining a pressure drop across the filter from the inflow area and the outflow area of the filter. Normalizing the measured pressure drop to provide a normalized pressure drop according to a predetermined normalization pressure level at a predetermined temperature for a model filter. Comparing the normalized pressure drop to a pressure drop model including a relation between the pressure drop across a filter and exhaust mass flow to the filter. Determining a pressure deviation between the normalized pressure drop and a pressure drop value calculated based on the pressure drop model and the present exhaust gas flow. Controlling the pressure drop across the filter for reducing the pressure deviation.

An automotive vehicle includes an internal combustion engine that outputs exhaust gas from a cylinder, and an active thermal management system. The active thermal management system flows coolant around the cylinder thereby varying an exhaust temperature of the exhaust gas. An electronic engine controller controls the internal combustion engine and the active thermal management system. The engine controller generates a control signal to selectively operate the active thermal management system in a normal mode, a thermal increase mode, and a thermal decrease mode. The normal mode flows the coolant at a first coolant temperature. The thermal increase mode flows the coolant at a second coolant temperature greater than the first coolant temperature thereby increasing the exhaust temperature of the exhaust gas. The thermal decrease mode flows the coolant at a third coolant temperature less than the first coolant temperature thereby decreasing the exhaust temperature of the exhaust gas.