A vehicle control method is provided for controlling a vehicle in which a clutch provided on a power transmission path between an engine and a drive wheel is disconnected when a shift range is a non-driving range and the clutch is connected when the shift range is a driving range. The vehicle control method controls the engine to a prescribed idling speed, controls engine torque to a negative torque by delaying an ignition timing of the engine; and causes the prescribed idling speed to drop within a prescribed amount of time needed for the clutch to switch from being disconnected to being connected when the shift range is switched from the non-driving range to the driving range.

A vehicle control method is provided for controlling a vehicle in which a clutch provided on a power transmission path between an engine and a drive wheel is disconnected when a shift range is a non-driving range and the clutch is connected when the shift range is a driving range. The vehicle control method controls the engine to a prescribed idling speed, controls engine torque to a negative torque by delaying an ignition timing of the engine; and causes the prescribed idling speed to drop within a prescribed amount of time needed for the clutch to switch from being disconnected to being connected when the shift range is switched from the non-driving range to the driving range.

An ECU avoids engine stall by putting a compressor into a stationary state in a case where the rotation speed of a crankshaft is equal to or less than a predetermined speed during an idle operation of an internal combustion engine. During the idle operation, the ECU calculates a total load torque applied to the crankshaft by the compressor and an alternator. The ECU calculates the maximum torque of the internal combustion engine during the idle operation based on a target speed during the idle operation. Then, the ECU raises the predetermined speed in a case where the value obtained by subtracting the load torque from the maximum torque is equal to or less than a predetermined value.

An ECU avoids engine stall by putting a compressor into a stationary state in a case where the rotation speed of a crankshaft is equal to or less than a predetermined speed during an idle operation of an internal combustion engine. During the idle operation, the ECU calculates a total load torque applied to the crankshaft by the compressor and an alternator. The ECU calculates the maximum torque of the internal combustion engine during the idle operation based on a target speed during the idle operation. Then, the ECU raises the predetermined speed in a case where the value obtained by subtracting the load torque from the maximum torque is equal to or less than a predetermined value.

A control device for the internal combustion engine includes a pulsation detector, a path length calculator, and an anomaly detector. The pulsation detector detects the pulsation of the intake air flowing through the intake passage based on output signals from the air flowmeter. The path length calculator calculates the path length, which is a parameter that is correlated with the degree of the pulsation, based on the pulsation of the intake air detected by the pulsation detector. The anomaly detector determines that the fresh air passage is detached if the path length calculated by the path length calculator is less than or equal to a determination value and detects an anomaly in the fresh air passage.

A control device for the internal combustion engine includes a pulsation detector, a path length calculator, and an anomaly detector. The pulsation detector detects the pulsation of the intake air flowing through the intake passage based on output signals from the air flowmeter. The path length calculator calculates the path length, which is a parameter that is correlated with the degree of the pulsation, based on the pulsation of the intake air detected by the pulsation detector. The anomaly detector determines that the fresh air passage is detached if the path length calculated by the path length calculator is less than or equal to a determination value and detects an anomaly in the fresh air passage.

A method for operating an idling control device for a motor vehicle. The idling control device specifies a total setpoint torque including a setpoint torque of an electric motor and a setpoint torque of an internal combustion engine which interacts with the electric motor, and sets the setpoint torques by respective control paths. In a first operating mode the idling control device sets a requested total setpoint torque only via the control path of the internal combustion engine by at least one control intervention, and in a second operating mode the idling control device sets the requested total setpoint torque by at least one control intervention via the control path of the internal combustion engine and by at least one control intervention via the control path of the electric motor. The control interventions via the control path of the internal combustion engine consist of at least one predetermined slow control intervention, and the control interventions in the control path of the electric motor consist of at least one predetermined fast control intervention, which intervenes with a higher rate of change over time than the at least one predetermined slow control intervention.

A method for controlling an engine of a vehicle going downhill with a throttle operator in an idle position, and a driven pulley of a CVT initially having a driven pulley speed below a predetermined driven pulley speed, includes: determining a first speed, the first speed being proportional to the driven pulley speed; as the driven pulley speed increases and the driven pulley speed is below the predetermined driven pulley speed, increasing an actual engine speed as the driven pulley speed increases; the actual engine speed being an engagement speed when the driven pulley speed is the predetermined driven pulley speed; and as the driven pulley speed continues to increase and the driven pulley speed is above the predetermined driven pulley speed: controlling the engine to operate under conditions corresponding to an engine braking speed thereby causing engine braking, the engine braking speed being less than the actual engine speed.

A method for controlling an engine of a vehicle going downhill with a throttle operator in an idle position, and a driven pulley of a CVT initially having a driven pulley speed below a predetermined driven pulley speed, includes: determining a first speed, the first speed being proportional to the driven pulley speed; as the driven pulley speed increases and the driven pulley speed is below the predetermined driven pulley speed, increasing an actual engine speed as the driven pulley speed increases; the actual engine speed being an engagement speed when the driven pulley speed is the predetermined driven pulley speed; and as the driven pulley speed continues to increase and the driven pulley speed is above the predetermined driven pulley speed: controlling the engine to operate under conditions corresponding to an engine braking speed thereby causing engine braking, the engine braking speed being less than the actual engine speed.

Systems and methods for controlling engine idle speed based on electrical load are provided. A system includes a logic device configured to perform various operations for controlling an idle speed of an engine. The logic device is configured to determine a state of charge (SOC) of a battery, a maximum output of an alternator at a current idle speed of an engine, and a load on the alternator. The logic device is further configured to initiate an increased idle speed of the engine based on the determined SOC of the battery and based on the load being greater than the maximum output. The logic device is further configured to initiate a decreased idle speed of the engine based on the SOC being less than an SOC threshold. Associated methods are also provided.