A system includes an exhaust aftertreatment system in exhaust gas receiving communication with an engine including a plurality of cylinders where the engine is structured to operate according to low load conditions and where a controller is structured to determine that at least one diesel emissions fluid (DEF) doser is frozen based on at least one of an ambient air temperature and a DEF source temperature. The controller is structured to operate the engine according to a skip-fire mode in response to a DEF flag indicating that the at least one DEF doser is frozen. The skip-fire mode comprises firing a portion of the plurality of cylinders that is less than a total amount of cylinders of the plurality of cylinders. The controller is structured to discontinue the skip-fire mode in response to determining that the at least one DEF doser is likely thawed.

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, apparatus, and method for controlling an engine system can provide fuel reactivity compensation control for an engine of the engine system. Pilot fuel quantity supplied to the engine can be controlled using a nitrous oxide (NOx) error. Likewise, air-to-fuel ratio (AFR) for the engine can be controlled using the NOx error. Each of a pilot fuel offset and an AFR control trim can be generated using the NOx error. The pilot fuel offset and the AFR control trim can be used to control the pilot fuel quantity and the AFR, respectively.

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.

The invention relates to a method to heat exhaust gases to a selected specific temperature by fuel injection control in an internal combustion engine (112), which engine comprises a control unit (115) registering the currently requested load and determining a required fuel amount in response to the requested load. The method involves registering low load operation of the internal combustion engine; registering an input from at least one exhaust after-treatment system (121) sensor indicating a detected condition; determining an exhaust temperature requirement for the detected condition and calculating a target exhaust temperature; selecting a group of cylinders to be regulated for achieving the target exhaust temperature; calculating a ratio for desired 1.sup.st and 2.sup.nd fuel amounts to be injected alternately in consecutive induction strokes for the selected group of cylinders to achieve the target exhaust temperature; wherein the ratio defines an offset between an increased 1.sup.st fuel amount to be injected in a cylinder of the selected group of cylinders for every second induction stroke, and a reduced 2.sup.nd fuel amount to be injected for the intermediate induction strokes.

A method for estimating the ageing of an exhaust gas sensor (16) placed in an exhaust line (14) of a diesel internal combustion engine (10) of an industrial vehicle (1) includes: —acquiring (S100) an initial value of an estimated remaining lifetime (50) of the exhaust gas sensor; —measuring (S102) the time spent by the engine in each of several predefined engine operation modes during a predefined time period; —for each of the engine operation modes, calculating (S104) a lifetime loss value depending on the time spent by the engine in said engine operation mode during the predefined time period and on a predefined ageing rate associated to said engine operation mode; —updating (S106) the estimated remaining lifetime value by subtracting each calculated lifetime loss value from the initial value.

An ECU stores and holds in a memory unit NOx information which is information concerning NOx in an exhaust gas flowing through an exhaust system of an onboard engine of a vehicle or NOx purification by a catalyst placed in the exhaust system. The ECU includes a parameter acquisition unit that acquires an NOx parameter, which is an outflow quantity of NOx flowing out to a downstream side of the catalyst or a correlation value correlating to the outflow quantity of NOx, according to a working state of the engine, an integrated value computation unit that computes a parameter integrated value by integrating NOx parameters acquired by the parameter acquisition unit, and a storage processing unit that stores in the memory unit the parameter integrated value as the NOx information.

The present disclosure describes methods for evaluating ammonia storage capacity of a close-coupled SCR unit while remaining compliant with prescribed emissions limits, methods of controlling an emission aftertreatment system including multiple SCR units and emission management systems for a vehicle including an internal combustion engine and an emission aftertreatment system that includes two or more SCR units.

A method of reducing cold start emissions in a series mode hybrid electric vehicle, including an internal combustion engine with an exhaust duct having a catalyst and a downstream oxygen sensor, an output of the combustion engine being connected to an electric generator with a power output of at least 10 kW that is connected to an electric motor which is coupled to a drive shaft of two or more wheels. The method includes detecting a cold start condition, injecting fuel into the engine such that combustion at a lambda value, λ, is achieved for which λ>1, running the engine at a speed of 1000 rpm or higher, determining if the efficiency of the catalyst reaches a first level, setting λ to about 1 after the predetermined efficiency level of the catalyst has been reached, and reducing the speed to working conditions when the catalyst efficiency reaches a second level.

A method of two-step variable valve lift (VVL) malfunction avoidance learning control may include: in a two-step VVL system which is operated with a main lift and a secondary lift, verifying, by an electronic control unit (ECU), an operation avoidance area based on locking of a lock pin of a cam follower ; performing VVL operation learning, in which a failure of occurrence of the second lift is determined on the basis of a locking failure of the cam follower due to an initially set value of the operation avoidance area; and reflecting the operation avoidance area to the two-step VVL system with a corrected set value which is obtained through the VVL operation learning.