A powertrain system includes a port injection internal combustion engine. A first start process is a process in which fuel is enclosed in a compression stroke cylinder when the engine is stopped, and based on a stored crank stop position, ignition is performed in a first cycle of the compression stroke cylinder upon engine start. A second start process is a process in which, based on the stored crank stop position, fuel injection is performed for an intake stroke cylinder while the engine is stopped, and based on the stored crank stop position, ignition is performed in the first cycle of the intake stroke cylinder upon engine start. When a catalyst temperature at the time engine start is requested is equal to or higher than a first threshold, a control device starts the internal combustion engine by at least one of the first start process and the second start process.

A vehicle includes an engine having an intake manifold and an exhaust manifold. An exhaust system is connected to the exhaust manifold and has an aftertreatment device. The aftertreatment device has a body defining inlet and outlet cones, a heating element, and a catalyst disposed in the body between the cones. An air-circulation system has conduit extending from downstream of the catalyst to the intake manifold and an air-circulation device configured to circulate air from the outlet cone, through the conduit to the intake manifold, through the engine, to the inlet cone, and through the aftertreatment device.

Methods and systems for improving fuel economy and reducing emissions of a vehicle with an electric motor, an engine, an energy storage device, and a controller are disclosed. The method includes obtaining current state information including a current hybrid control surface, and determining a target hybrid control surface for the vehicle based on the current state information.

Methods and systems are provided for maintaining efficiency of a catalyst that is positioned in an exhaust system downstream of an internal combustion engine. In one example, the catalyst may be heated via supplying fuel to a cylinder that does not combust the fuel. The fuel may be oxidized at the catalyst via excess oxygen in the exhaust system.

A vehicle includes an engine having an intake manifold and an exhaust manifold. An exhaust system is connected to the exhaust manifold and has an aftertreatment device. The aftertreatment device has a body defining inlet and outlet cones, a heating element, and a catalyst disposed in the body between the cones. An air-circulation system has conduit extending from downstream of the catalyst to the intake manifold and an air-circulation device configured to circulate air from the outlet cone, through the conduit to the intake manifold, through the engine, to the inlet cone, and through the aftertreatment device.

Systems and methods for operating an internal combustion engine that is included in a hybrid vehicle are described. In one example, the internal combustion engine is operated in a two stroke mode during cold starting to increase mass flow to an electrically heated catalyst so that engine emissions may be reduced.

A system includes an internal combustion engine producing exhaust gases as a byproduct of operation and an aftertreatment system that treats the exhaust gases. The system further includes a controller that is structured to functionally execute operations to enhance the temperature of the aftertreatment system. The controller includes an operating condition monitoring module that interprets a temperature value at a position upstream of a catalyst positioned in the aftertreatment system. The controller further includes an operating condition management module that interprets a threshold temperature value, and an engine management module that provides an engine operation command to continue engine operation in response to the temperature value being at least equal to the threshold temperature value.

A system includes a valve actuation system, a pre-lubrication pump coupled to a lubrication circuit and configured to provide oil to the valve actuation system, a catalyst for receiving and treating exhaust gasses, and a controller. The controller is configured to identify an engine start request and determine whether the catalyst temperature is below a first threshold value. In response to determining that the catalyst temperature is below the first threshold value, the controller actuates the pre-lubrication pump to direct lubricant to the valve actuation system, controls the valve actuation system to deactivate at least one cylinder of an engine, and, subsequent to deactivating the at least one cylinder of the engine, cranks the engine.

A method for operating a hybrid motor vehicle. In one example, the vehicle comprises an internal combustion engine (10) and at least one electric motor (20). As long as at least one parameter of an exhaust gas aftertreatment system (12) of the internal combustion engine (10) lies outside a given range, the starting of the internal combustion engine (10) is delayed and the internal combustion engine (10) is dragged by the electric motor (20). At the same time at least one measure is carried out which changes the parameter.

Methods and systems for operating an engine with an electrically heated catalyst and an electrically driven compressor are described. In one example, the electrically driven compressor and the electrically heated catalyst are activated before an engine start so that vehicle emissions may be reduced more efficiently at engine starting and thereafter.