Abstract: A control method of a vehicle includes a step of running the vehicle in an EV running mode in accordance with an operation of a driver, a step of performing a warming-up running, when it is determined that warming up is required, and a step of prohibiting the EV running mode such that the warming up running can be performed.

Abstract: A rotational fluctuation is given as a variation in rotation speed of a crankshaft at every specific crank angle, that is, at every 120 degrees, corresponding to an ignition timing in each cylinder of a six-cylinder engine. The engine misfire identification technique of the invention calculates a difference between a specific rotational fluctuation at a specific crank angle and a previous rotational fluctuation at a crank angle of 360 degrees before the specific crank angle as a rotational fluctuation difference, and sums up the specific rotational fluctuation at the specific crank angle and the previous rotational fluctuation at the crank angle of 360 degrees before the specific crank angle to give a total rotational fluctuation.

Abstract: The engine misfire detection apparatus of the invention successively determines whether a rotational fluctuation difference Nxd360 as a difference between a rotational fluctuation Nxd at a certain crank angle CA of an engine and a rotational fluctuation Nxd at a 360 degree-prior crank angle CA exceeds a predetermined reference value A1 (step S150) and whether a rotational fluctuation difference Nxd720 as a difference between the rotational fluctuation Nxd at the certain crank angle CA and a rotational fluctuation Nxd at a 720 degree-prior crank angle CA exceeds a predetermined reference value B1 (step S160).

Abstract: A delay time for delaying starting of an internal combustion engine in a hybrid vehicle is set to a predetermined time based on an engine coolant temperature and a state of an air conditioner switch. Starting of the engine is delayed for the predetermined time if it is determined that a vehicle can run using only a motor based on a required torque, a required power and an SOC of the battery. The predetermined time is determined based on a time necessary for completing preheating of an engine by a preheating device, preparations of sensors such as an air-furl ratio sensor, and warming-up of an exhaust gas purifying device. As a result, it is possible to efficiently perform start of the engine and operation immediately after the engine start, and to make control at the engine start time simple.

Abstract: In the case of non-execution of catalyst warm-up acceleration control, the engine misfire detection procedure compares a 30-degree rotation time computed as a time required for a 30-degree rotation of an engine crankshaft with preset reference values Tref1 and Tref2 and distinctly detects the occurrence of intermittent engine misfires and the occurrence of either a single engine misfire or consecutive engine misfires (steps S120 to S150). In the case of execution of the catalyst warm-up acceleration control, the engine misfire detection procedure compares the 30-degree rotation time computed as the time required for a 30-degree rotation of the engine crankshaft with preset reference values Tref3 and Tref4 and distinctly detects the occurrence of the consecutive engine misfires and the occurrence of either the single engine misfire or the intermittent engine misfires (steps S160 to S190).

Abstract: The engine misfire detection apparatus of the invention successively determines whether a rotational fluctuation difference Nxd360 as a difference between a rotational fluctuation Nxd at a certain crank angle CA of an engine and a rotational fluctuation Nxd at a 360 degree-prior crank angle CA exceeds a predetermined reference value A1 (step S150) and whether a rotational fluctuation difference Nxd720 as a difference between the rotational fluctuation Nxd at the certain crank angle CA and a rotational fluctuation Nxd at a 720 degree-prior crank angle CA exceeds a predetermined reference value B1 (step S160).

Abstract: An ECU executes a program including the steps of detecting an engine speed, determining whether the engine speed is at least a threshold value or not, detecting a VVT advance angle calculation count after restarting the engine, determining whether a VVT advance angle calculation count is at least a threshold value or not, detecting a VVT advance angle amount, determining whether the VVT advance angle amount is at least a threshold value or not, determining whether the engine is in a stop sequence or not, setting a VVT abnormality determination permission flag to detect a VVT displacement amount if the engine speed is at least the threshold value, the VVT advance angle calculation count is at least the threshold value, the VVT advance angle amount is at least the threshold value, and the engine is not in the stop sequence, and determining that the VVT is abnormal if the VVT displacement amount is less than a criterion threshold value.

Abstract: A rotational fluctuation is given as a variation in rotation speed of a crankshaft at every specific crank angle, that is, at every 120 degrees, corresponding to an ignition timing in each cylinder of a six-cylinder engine. The engine misfire identification technique of the invention calculates a difference between a specific rotational fluctuation at a specific crank angle and a previous rotational fluctuation at a crank angle of 360 degrees before the specific crank angle as a rotational fluctuation difference, and sums up the specific rotational fluctuation at the specific crank angle and the previous rotational fluctuation at the crank angle of 360 degrees before the specific crank angle to give a total rotational fluctuation.

Abstract: An engine ECU learns a base duty ratio command of an actuator for driving a throttle valve as an operation level of engine control on condition that a target idle rotation speed Nei* enters a predetermined rotation speed range during idling of an engine as one prerequisite. When the learning is incomplete, the engine ECU rejects an up request of the target idle rotation speed Nei* sent from an air conditioner ECU and prohibits the target idle rotation speed Nei* from being changed. The control procedure of the invention effectively prohibits a change of the target idle rotation speed Nei* under the condition of incomplete learning of the operation level of engine control. The prohibition of the change desirably keeps the target idle rotation speed Nei* within the predetermined rotation speed range, thus preventing failed fulfillment of the learning condition and ensuring the sufficient learning opportunities of the operation level of engine control.

Abstract: The technique of the invention determines whether input data for driving and controlling a cooling fan have any abnormality (steps S100 and S110), sets an actual drive level F* of the cooling fan to a high level (Hi) in the event of detection of any abnormality (step S130), and controls a fan motor to drive the cooling fan at the set drive level F* (step S140). This arrangement effectively prevents a temperature rise to an abnormally high level in any of an engine and motors even in the event of any abnormality arising in the input data.

Abstract: A delay time for delaying starting of an internal combustion engine in a hybrid vehicle is set to a predetermined time based on an engine coolant temperature and a state of an air conditioner switch. Starting of the engine is delayed for the predetermined time if it is determined that a vehicle can run using only a motor based on a required torque, a required power and an SOC of the battery. The predetermined time is determined based on a time necessary for completing preheating of an engine by a preheating device, preparations of sensors such as an air-furl ratio sensor, and warming-up of an exhaust gas purifying device. As a result, it is possible to efficiently perform start of the engine and operation immediately after the engine start, and to make control at the engine start time simple.

Abstract: A vehicle is equipped with a planetary gear mechanism including a sun gear, a carrier, and a ring gear that are respectively connected to a first motor, an engine, and a driveshaft. A second motor is further linked to the driveshaft. An air-fuel ratio sensor located in an exhaust system of the engine detects the air-fuel ratio while the engine is rotated in a fuel cut state. Normality or abnormality of the air-fuel ratio sensor is identified, based on a result of determination whether the detected air-fuel ratio is out of a specified normal range. When engine stop conditions for stopping the operation (rotation) of the engine are satisfied during execution of failure detection of the air-fuel ratio sensor (steps S300 and S310), the drive control of the invention maintains the rotation of the engine in the fuel cut state until completion of the failure detection of the air-fuel ratio sensor and controls the first motor to motor the engine (step S330).

Abstract: A delay time for delaying starting of an internal combustion engine in a hybrid vehicle is set to a predetermined time based on an engine coolant temperature and a state of an air conditioner switch. Starting of the engine is delayed for the predetermined time if it is determined that a vehicle can run using only a motor based on a required torque, a required power and an SOC of the battery. The predetermined time is determined based on a time necessary for completing preheating of an engine by a preheating device, preparations of sensors such as an air-furl ratio sensor, and warming-up of an exhaust gas purifying device. As a result, it is possible to efficiently perform start of the engine and operation immediately after the engine start, and to make control at the engine start time simple.

Abstract: The auto engine start control of the invention regulates a throttle valve to a restricted opening to reduce an air intake flow at an ordinary start of an engine (step S140). When the driver stamps on an accelerator pedal to raise an engine power demand Pe* to or above a preset threshold value Pref, the auto engine start control regulates the throttle valve to a standard opening to ensure the air intake flow corresponding to the engine power demand Pe* (step S150) and thereby cranks the engine. This arrangement desirably dampens potential vibration induced by ignition at the ordinary start of the engine, while ensuring prompt output of the required driving force from the engine under the condition of the higher engine power demand Pe*.

Abstract: A control method of a vehicle includes a step of running the vehicle in an EV running mode in accordance with an operation of a driver, a step of performing a warming-up running, when it is determined that warming up is required, and a step of prohibiting the EV running mode such that the warming up running can be performed.

Abstract: When a starter switch is switched from OFF to ON, a hybrid ECU determines that a driver intends to start driving a vehicle, reads a temperature of each of items (engine coolant, injectors, lubricating oil, and the like), and makes a determination on the necessity of preheating depending on whether each of the items has reached a corresponding one of suitable temperatures. If preheating is required, the hybrid ECU sets an engine start permission flag so as to prohibit the engine from being started, and instructs an engine ECU to preheat the item requiring preheating. On the other hand, if every one of the items has reached the suitable temperature range of its own, the hybrid ECU determines that preheating is not required, and sets the engine start permission flag so as to permit the starting of the engine.

Abstract: The control technique of the invention sets smaller values to an engine stop reference value and an engine start reference value in the state of use of a regular fuel, compared with values in the ordinal state. When a calculated engine power demand Pe* is less than the engine stop reference value, the control stops the operation of the engine. When the calculated engine power demand Pe* exceeds the engine start reference value, on the other hand, the control starts the operation of the engine. This arrangement facilitates the start of the engine in the state of use of the regular fuel, compared with the start in the ordinary state. A corrective revolution speed ?N is added to a target revolution speed Ne* of the engine, in order to respond to a decrease in output power from the internal combustion engine.

Abstract: The auto engine start control of the invention regulates a throttle valve to a restricted opening to reduce an air intake flow at an ordinary start of an engine (step S140). When the driver stamps on an accelerator pedal to raise an engine power demand Pe* to or above a preset threshold value Pref, the auto engine start control regulates the throttle valve to a standard opening to ensure the air intake flow corresponding to the engine power demand Pe* (step S150) and thereby cranks the engine. This arrangement desirably dampens potential vibration induced by ignition at the ordinary start of the engine, while ensuring prompt output of the required driving force from the engine under the condition of the higher engine power demand Pe*.

Abstract: The temperature of a component provided in or associated with an internal combustion engine is estimated with no regard to the automatic stop and the automatic start of the internal combustion engine, and at least one of the estimated temperature of the component and a parameter used to estimate the same temperature is initialized in response to the internal combustion engine being started non-automatically.

Abstract: The control technique of the invention sets smaller values to an engine stop reference value and an engine start reference value in the state of use of a regular fuel, compared with values in the ordinal state. When a calculated engine power demand Pe* is less than the engine stop reference value, the control stops the operation of the engine. When the calculated engine power demand Pe* exceeds the engine start reference value, on the other hand, the control starts the operation of the engine. This arrangement facilitates the start of the engine in the state of use of the regular fuel, compared with the start in the ordinary state. A corrective revolution speed ?N is added to a target revolution speed Ne* of the engine, in order to respond to a decrease in output power from the internal combustion engine.