Systems and methods for operating an engine of a vehicle that may be automatically stopped and started are disclosed. In one example, a speed at which a vehicle system induced automatic engine stop inhibit request is cleared may be adjusted to permit automatic engine stopping during a wide variety of driving conditions so that fuel may be conserved and the possibility of disturbing vehicle occupants may be reduced.

An engine includes an EGR device and a water-cooled heat exchanger. The water-cooled heat exchanger is provided on a downstream side of an EGR gas-introduction portion of an intake passage into which EGR gas is to be introduced and exchanges heat with gas flowing in the intake passage. A control device is programmed to execute condensed water-suppression control that supplies coolant having a temperature higher than the temperature of the gas heat-exchanged in the water-cooled heat exchanger to the water-cooled heat exchanger while a hybrid vehicle is traveling in a state in which the engine is stopped.

Methods and systems for diagnosing operation of an exhaust gas recirculation system of an internal combustion engine are described. In one example, the EGR system is diagnosed while an engine that includes the EGR system is not rotating and combusting fuel. The EGR system is diagnosed when the engine is not operating so that vehicle passengers are not disturbed by the diagnostic and so that flow estimates through the EGR system may not be disturbed by pressure changes that may be related to combustion within the engine.

A control device for an internal combustion engine executes an automatic stop control and automatic start-up control for an intermittent operation of the internal combustion engine. In the automatic start-up control, the control device is configured to commence a restart by starting fuel injection from a fuel-injection-start cylinder. In the automatic stop control, the control device is configured to: execute an air-fuel-ratio rich processing that controls an air-fuel ratio such that the air-fuel ratio becomes richer than the stoichiometric air-fuel ratio before a start of the fuel cut; execute a throttle closing processing that closes a throttle valve in synchronization with the fuel cut; and execute a throttle opening processing approaches the atmospheric air pressure before a cylinder destined to be the fuel-injection-start cylinder later completes the last intake stroke in the course of the engine stop after execution of the throttle closing processing.

According to one embodiment, a work vehicle includes: a traveling vehicle body; an engine supported by the traveling vehicle body; a power transmission device which transmits power of the engine to a wheel, and has a clutch member which is supported to be movable between a transmission position and a block position; a braking device which brakes the wheel; a brake control unit which allows the clutch member to move to the block position and the braking device to operate in a case where the traveling vehicle body is braked; a brake determination unit which determine whether the traveling vehicle body is braked in a case where the braking device is operated; and an engine control unit which stops the engine in a case where the traveling vehicle body is not braked on the basis of a determination result of the brake determination unit.

Methods and systems are provided for preheating a fuel vapor storage canister in an evaporative emissions system prior to a vehicle start. In one example, a method may include learning common vehicle routes and identifying routes in which fuel vapor storage canister preheating is indicated, such as routes that will enable fuel vapors to be purged to an engine intake shortly after the vehicle start. Then, in anticipation of an identified route for fuel vapor storage canister preheating, a vehicle controller may be transitioned from a sleep mode to an awake mode prior to the vehicle start in order to commence a fuel vapor storage canister preheating routine.

An ECU is applied to an engine system including an engine and an MG. The ECU determines whether or not a piston is located at a position, at which compression reactive force is received, at a time point at which engine speed reaches zero after combustion of the engine is stopped. Further, in a case where the ECU determines that the piston is located at the position at which compression reactive force is received, the ECU stops the piston by applying positive torque on a positive rotation side to a crank shaft by the MG.

Methods and systems are provided for rationalizing a hydrocarbon sensor in a hybrid vehicle, the hydrocarbon sensor used for feed-forward air/fuel ratio control during fuel vapor canister purging events. In one example, a method comprises routing blow-by gasses from a crankcase of an engine of the vehicle to an intake manifold of the engine and then to a fuel vapor storage canister, and indicating whether the hydrocarbon sensor is functioning as desired based on a magnitude of a response of the hydrocarbon sensor during the routing. In this way, the hydrocarbon sensor may be diagnosed under conditions when the canister is substantially free from fuel vapors, and where engine run-time is limited.

A method for fault diagnosis in an electronic control unit (ECU) of an engine fuel injection system. The method includes keeping the ECU and the engine fuel injection system at a set of pre-defined conditions, measuring an electrical current consumption of the ECU, and detecting a status of the ECU based on the measured electrical current consumption. Keeping the ECU and the engine fuel injection system at the set of pre-defined conditions includes switching the ECU on by switching the engine fuel injection system on, and keeping the engine fuel injection system at a not-running state. Detecting the status of the ECU based on the measured electrical current consumption includes detecting a normal status responsive to the measured electrical current consumption being in a normal electrical current range, detecting a first hardware defect in the ECU responsive to the measured electrical current consumption being in a first electrical current range, and detecting a second hardware defect in the ECU responsive to the measured electrical current consumption being in a second electrical current range.

A vehicle diagnosis system determines whether a vehicle has an abnormality in a temporal engine stop function or a power regeneration function that negates a greenhouse gas reduction effect of the engine. When the vehicle diagnosis system determines an abnormality, the vehicle diagnosis system provides a notification of the abnormality.