Systems and methods for operating an internal combustion engine that may be automatically stopped and started are described. In one example, an engine is rotated in a reverse direction after an engine stop so that a belt integrated starter/generator may rotate the engine in a forward direction and utilize the inertia of the engine to rotate trough top-dead-center compression stroke, thereby starting the engine.

Provided is a novel control apparatus for a vehicle which allows the number of stops and restarts to be reduced while performing engine stop and coasting control. The configuration is such that, when there is a high probability of restarting an engine under circumstances where engine stop and coasting control is performed, the engine is maintained in idling operation while only the clutch is disengaged. For example, if it is determined that there is a high probability of restarting due to a change in the acceleration of a host vehicle or a preceding vehicle, the clutch is disengaged and the vehicle is coasted. Since the engine is maintained in an idle state, there is no need for restarting, and the number of restarts can be minimized.

Systems for efficiently starting an engine of a hybrid electric vehicle are provided. An example of a system comprises a first processor and a second processor. The second processor is configured to determine when to start an internal combustion engine, cause energy to be supplied from an energy storage device to a generator/motor to cause the generator/motor and crankshaft to rotate to at least a hold speed, transmit a first instruction to a first processor when determining that the internal combination engine should be started. The first processor does not supply fuel to at least one cylinder of the internal combustion engine in response to the first instruction. The second processor is configured to transmit a second instruction to the first processor after a variable period of time has elapse after the generator/motor or crankshaft has reached at least the hold speed.

Apparatuses, systems, methods, and techniques relating to engine start/stop functionality are disclosed. Automatic engine start/stop controls can be disabled during engine operating conditions in which one or more combustion parameters indicate a lack of combustion stability in one or more cylinders of the engine. Engine start/stop controls are enabled when the one or more combustion parameters satisfy combustion parameter conditions indicating combustion stability in the one or more cylinders.

A vehicle method for barometric pressure identification, including adjusting engine operation responsive to barometric pressure, the barometric pressure based on a pressure change at a sector of the fuel system when the sector is sealed with the vehicle travelling. The method may utilize a pressure change at the sealed sector of the fuel system, such as a sealed fuel tank, to identify barometric pressure, even with the engine off for extended durations of vehicle travel. As such, in a hybrid-vehicle application, including during hill descents in which the engine is maintained off, barometric pressure can still be updated.

A vehicle method for barometric pressure identification, including adjusting engine operation responsive to barometric pressure, the barometric pressure based on a pressure change at a sector of the fuel system when the sector is sealed with the vehicle travelling. The method may utilize a pressure change at the sealed sector of the fuel system, such as a sealed fuel tank, to identify barometric pressure, even with the engine off for extended durations of vehicle travel. As such, in a hybrid-vehicle application, including during hill descents in which the engine is maintained off, barometric pressure can still be updated.

Provided is a novel control apparatus for a vehicle which allows the number of stops and restarts to be reduced while performing engine stop and coasting control. The configuration is such that, when there is a high probability of restarting an engine under circumstances where engine stop and coasting control is performed, the engine is maintained in idling operation while only the clutch is disengaged. For example, if it is determined that there is a high probability of restarting due to a change in the acceleration of a host vehicle or a preceding vehicle, the clutch is disengaged and the vehicle is coasted. Since the engine is maintained in an idle state, there is no need for restarting, and the number of restarts can be minimized.

A vehicle method for barometric pressure identification, including adjusting engine operation responsive to barometric pressure, the barometric pressure based on a pressure change at a sector of the fuel system when the sector is sealed with the vehicle travelling. The method may utilize a pressure change at the sealed sector of the fuel system, such as a sealed fuel tank, to identify barometric pressure, even with the engine off for extended durations of vehicle travel. As such, in a hybrid-vehicle application, including during hill descents in which the engine is maintained off, barometric pressure can still be updated.

An engine control system for an auto-stop/start vehicle includes an auto-stop/start module that generates an auto-stop command for shutting down an engine while an ignition is ON and subsequently generates an auto-start command for re-starting the engine. The system includes an actuator control module that disables an engine load, parks exhaust and intake cam phasers, disables fuel, sets a first throttle opening, monitors a crankshaft rotational position, speed, and deceleration, sets a second throttle opening for a predetermined duration if a piston simultaneously crosses a target position below a target engine speed and below a target degrees of rotation remaining, sets a third throttle opening, and determines if an engine speed is below a threshold speed before setting a fourth throttle opening when the engine speed is below the threshold speed, and causes the piston to rest in a predetermined position range.

A vehicle control apparatus includes at least one electronic control unit (50). The electronic control unit detects a negative pressure that is generated in a negative pressure chamber (34) of a braking operation support device (32). The electronic control unit prohibits, based on the detected negative pressure of the negative pressure chamber, an internal combustion engine (26) from automatically stopping when determining that a driver does not perform the braking operation and that a speed of the internal combustion engine is at a threshold or higher continuously for a specified time period or longer. The negative pressure is generated in the negative pressure chamber in response to rotation of the internal combustion engine. The braking operation support device supports, with the negative pressure in the negative pressure chamber, the driver to perform the braking operation.