In one aspect, a method for controlling an engine system includes starting the engine system, activating an engine idling reduction mode allowing automatic shutdown and automatic restarting of an engine, disallowing automatic shutdown of the engine within the engine idling reduction mode if a state of charge of a voltage source is below a charge limit for permitting automatic shutdown of the engine, and modifying the charge limit as a function of a number of starts of the engine. Other aspects include a method for disallowing automatic shutdown of an engine if a voltage source has not achieved a fully charged condition, a method of triggering an automatic restarting of an engine, if the engine is automatically shutdown, based on at least two separate indicators of engine temperature, and a method of disallowing automatic shutdown of an engine if ambient temperature is less than a predetermined value.

A controller for a vehicle is configured to execute, when a state of charge of a battery is less than or equal to a threshold, a charging control to charge the battery with power that is generated by a motor generator using driving force of an internal combustion engine. The controller is also configured to obtain a temperature of the battery, set the threshold to a first threshold during a warm-up period, which is a period from a start of the internal combustion engine until the warm-up of the internal combustion engine is completed, set the threshold to a second threshold, which is greater than the first threshold, when the warm-up period ends, and set the second threshold to be greater when the temperature of the battery is a first temperature than when the temperature of the battery is a second temperature, which is higher than the first temperature.

Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include, during a cold start condition, operating an engine with a first number of cylinders unfired and a remaining number of cylinders fired during an engine cycle, opening an intake valve of an unfired cylinder of the first number of cylinders during an expansion stroke of the unfired cylinder, and opening an exhaust valve of the unfired cylinder during a compression stroke of the unfired cylinder. In this way, the unfired cylinders may provide the secondary air to the exhaust system during a stroke that increases mixing of the secondary air with burned exhaust gas from fired cylinders, thus increasing exotherm production in the exhaust system to increase a temperature of the catalyst.

A power system for a work vehicle includes an alcohol tank configured to store alcohol; a catalytic converter fluidly coupled to receive alcohol from the alcohol tank and configured to convert the alcohol into ether; and an engine including one or more piston-cylinder sets configured to selectively receive the alcohol stored in the alcohol tank and the ether converted by the catalytic converter and to combust the alcohol and the ether with air to produce mechanical power and exhaust gas.

Methods are provided for reducing exhaust gas emissions during a cold-start of an engine. In one example, a method may include generating a flame front in an exhaust port of an exhaust system, heating exhaust gas flowing into an emission control device of the exhaust system and thereby expediting the approach to a light-off temperature of the emission control device, and directing the flame front back to the cylinder as part of a combustion stroke of the four-stroke engine cycle.

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.

A method and system for operating a vehicle that includes an automatic transmission with a torque converter clutch is described. In one example, the method includes predicting a time that the torque converter clutch will open so that stopping rotation of the engine may be requested before the torque converter clutch is opened. The stopping rotation of the engine is requested to conserve fuel.

Systems and methods for operating an engine that is started via expansion stroke combustion are described. In one example, the method increases air flow through the engine during an engine stopping process so that a larger amount of air may be trapped in a cylinder that is on its expansion stroke so that greater amounts of engine torque may be provided during engine starting.

A valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, an EGR valve body. The housing includes a first upstream passage into which the EGR gas cooled by an EGR cooler flows, a second upstream passage into which the EGR gas that bypasses the EGR cooler flows, a junction connected to each of a gas-flow downstream side of the first upstream passage and a gas-flow downstream side of the second upstream passage, and a downstream passage connected to the first upstream passage and the second upstream passage via the junction. The bypass valve body opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage, rotates around an EGR valve axis.

A vehicle control apparatus includes a detector that detects an external temperature of a vehicle, a vehicle speed, and a coolant temperature of an engine, an input device that receives a signal for ON or OFF operations of a heating control, and a controller configured for determining a heating load depending on the heating control when the external temperature is less than a predetermined temperature and the signal for the ON operation of the heating control is input, and controls an operation of an integrated thermal management valve, a deactivation operation of cylinders included in the engine, and an operation of an active air flap, according to at least one of the heating load and the coolant temperature.