A method for operating a vehicle that includes a DC/DC converter is described. In one example, the method includes adjusting an output voltage of the DC/DC converter to increase torque of a belt integrated starter/generator. The output voltage of the DC/DC converter may be adjusted before and during engine cranking.

A method for operating a vehicle that includes a DC/DC converter is described. In one example, the method includes adjusting an output voltage of the DC/DC converter to increase torque of a belt integrated starter/generator. The output voltage of the DC/DC converter may be adjusted before and during engine cranking.

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 method for controlling a start of a vehicle using a controller includes: determining whether revolutions per minute (RPM) of an engine is within a reference range when start of the vehicle is requested; determining whether state data for controlling the vehicle satisfies a control condition for controlling a start of the vehicle when RPM of the engine is within the reference range; determining whether a position value of an accelerator pedal is less than or equal to a reference position value when the state data satisfies the control condition; determining whether a speed of the vehicle is greater than or equal to a reference speed when the position value of the accelerator pedal is less than or equal to the reference position value; and controlling a brake device when speed of the vehicle is greater than or equal to the reference speed.

In some embodiments, a vehicle includes a temperature monitoring controller. The temperature monitoring controller is a processor, control module, or other suitable hardware that is configured to receive temperature sensor values from an engine control module (ECM) when an ignition bus is in a powered on state, and to decide when the engine should be automatically started in order to maintain a temperature above a low temperature threshold. The temperature monitoring controller periodically causes an ignition bus of the vehicle to be placed in the powered on state when the engine is shut down in order to collect temperature sensor values. The temperature monitoring controller determines whether to automatically start the engine, and if not, determines how long to wait before collecting temperature sensor values again based on a rate of change of the temperature sensor values.

A valve timing adjustment device having a phase adjustment unit including an input rotator, a driving rotator that rotates in conjunction with a crankshaft, a driven rotator that rotates in conjunction with a camshaft that changes a relative rotation phase between the driving rotator and the driven rotator. A controller is configured to perform a startup phase control when operation of the internal combustion engine is started, the startup phase control including setting the relative rotation phase to a predetermined initial phase, and perform a startup preparation control during a period after the internal combustion engine is stopped and before the startup phase control is performed, the startup preparation control including changing the relative rotation phase.

A method for controlling a vehicle includes: receiving a detection signal to perform an idle stop and go (ISG) function; and controlling the vehicle to enter into an ISG state where a fuel supply to an engine is cut off and the engine stops when the vehicle decelerates or stops in response to the detection signal. The detection signal includes a fuel cut off signal that is in on state when the vehicle decelerates and in off state at a reference revolution per minute (RPM) of the engine, a gear engagement signal, and a brake pedal signal indicating whether the brake pedal of the vehicle is operated. A controller of the vehicle generates an ISG entry signal based on the fuel cut off signal, the gear engagement signal, and the brake pedal signal to enter the vehicle into the ISG state.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, the engine system may be installed in a hybrid vehicle, and, in response to a request to restart the engine while the vehicle is being propelled via motor torque only, the engine may be rotated unfueled via the motor torque at less than cranking speed while at least partially opening a valve disposed in a passage coupled between the first exhaust manifold and the intake passage. In another example, in response to the request to restart the engine, all exhaust valves of a second set of exhaust valves coupled to the second exhaust manifold may be deactivated.

A valve timing adjustment device having a phase adjustment unit including an input rotator, a driving rotator that rotates in conjunction with a crankshaft, a driven rotator that rotates in conjunction with a camshaft that changes a relative rotation phase between the driving rotator and the driven rotator. A controller is configured to perform a startup phase control when operation of the internal combustion engine is started, the startup phase control including setting the relative rotation phase to a predetermined initial phase, and perform a startup preparation control during a period after the internal combustion engine is stopped and before the startup phase control is performed, the startup preparation control including changing the relative rotation phase.

In some embodiments, a vehicle includes a temperature monitoring controller. The temperature monitoring controller is a processor, control module, or other suitable hardware that is configured to receive temperature sensor values from an engine control module (ECM) when an ignition bus is in a powered on state, and to decide when the engine should be automatically started in order to maintain a temperature above a low temperature threshold. The temperature monitoring controller periodically causes an ignition bus of the vehicle to be placed in the powered on state when the engine is shut down in order to collect temperature sensor values. The temperature monitoring controller determines whether to automatically start the engine, and if not, determines how long to wait before collecting temperature sensor values again based on a rate of change of the temperature sensor values.