The present disclosure provides a method in a vehicle, comprising detecting an engine stop opportunity and recording, in a memory, data corresponding to a first engine stop that occurred in response to detection of the engine stop opportunity. The method further includes detecting an engine stop inhibit, and recording, in a memory, data corresponding to a first missed engine stop wherein the first missed engine stop indicates detection of the engine stop opportunity without an engine stop in response to the detection of the engine stop opportunity.

Systems and methods for selecting and scheduling which of a plurality of engine starting devices starts an internal combustion engine of a hybrid vehicle are presented. In one example, a scheduled start of the internal combustion engine via a driveline disconnect clutch is withdrawn during conditions when both a transmission gear shift is requested or in process and when a driver urgency level is greater than a threshold level.

Systems and methods for operating a hybrid vehicle are presented. In one example, an integrated starter/generator (ISG) is operated in a speed control mode after an engine stop request. The ISG is prevented from stopping while engine rotational speed is greater than a threshold engine rotational speed so that the engine may be restarted via the ISG.

Systems and methods for operating a hybrid vehicle are described. In one example, the automatic engine stopping may be inhibited so that an engine may be restarted during change of mind conditions without generating a large driveline torque disturbance. The engine stopping may be inhibited based on a inhibit engine pull-down torque threshold.

Systems and methods for selecting which of a plurality of engine starting devices starts an internal combustion engine of a hybrid vehicle are presented. In one example, engine starting devices may be selected and operated while a vehicle is operating in a creep mode. The system and method may place a driveline disconnect clutch in a wait state or engage a flywheel starter to improve engine starting.

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine reaches a predetermined threshold speed, then a first restart sequence is initiated. If a restart request is made when the engine speed is less than the predetermined threshold speed but still greater than 0, then a second restart sequence is initiated.

An apparatus for controlling an engine start during refueling of a hybrid vehicle includes a controller configured to: stop an engine to block the engine start by sensing whether the vehicle enters into a refueling state in accordance with a fuel injection port open or closed state, a vehicle speed, and brake pedal state (BPS) information, and start the engine to release blocking of the engine start in accordance with a switchover to a hybrid electric vehicle (HEV) mode by sensing whether the refueling state has been released in accordance with the fuel injection port open or closed state, the vehicle speed, and acceleration pedal state APS) information.

Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.

A control method for an SSC function and an ISG function includes: determining, by a controller, whether a SSC activation condition is satisfied based on a vehicle running state information; stopping, by the controller, an engine and activating the SSC function by controlling a transmission to neutral when the SSC activation condition is satisfied; determining, by the controller, whether a first ISG operation condition including a first reference vehicle speed is satisfied based on the vehicle running state information in a state that the SSC function is activated; and deactivating, by the controller, the SSC function and activating the ISG function when it is determined that the first ISG operation condition is satisfied.

Systems and methods for operating a vehicle that includes an engine that may be automatically stopped and started are described. In one example, an amount of time to start an engine and a rate of engine acceleration are adjusted in response to what type of event triggered an automatic engine start.