A system and method for operating an automatic start/stop system in a motor vehicle having an internal combustion engine, an automatic transmission and a torque converter with an impeller disconnect clutch is disclosed. A controller may implement an engine start/stop system by, at appropriate times, stopping engine by halting fuel and restarting engine when propulsion is needed. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the torque converter may be disengaged to decouple the impeller and the engine to provide for fuel and emissions savings.

Methods and systems are provided for controlling a vehicle system including an engine that is selectively shut-down during engine idle-stop conditions, the vehicle system further including a hydraulically actuated transmission component. One example method comprises, during an idle-stop engine shut-down, adjusting a hydraulic actuation of the transmission component to adjust drag torque on the engine to stop the engine.

Systems and methods for cranking an engine of a hybrid vehicle that includes an electric machine to crank the engine and propel the vehicle are disclosed. In one example, engine cranking speed and engine cranking source are selected in response to vehicle operating conditions that may affect whether or not an electrical power source has sufficient energy to crank the engine.

A hybrid powertrain system includes an electric machine, a torque converter, a transmission, a hydraulic pump, and a controller, and it is arranged to transfer mechanical power to a driveline. The torque converter includes a clutch, a pump, and a turbine, and the electric machine is rotatably coupled to the hydraulic pump and to the torque converter pump. The hydraulic pump is fluidly connected to the transmission, and the controller is operably connected to the electric machine and the torque converter clutch. The controller is executable to determine an operator command, and control the electric machine to spin the hydraulic pump in a speed control mode and control the torque converter clutch in an open state. Upon achieving a desired minimum pump speed, the torque converter clutch is applied in a slip state and the electric machine is controlled in response to the operator command.

A method for improving operating a vehicle that includes an accelerator pedal is disclosed. In one example, the method assesses a vehicle for accelerator pedal degradation and applies control actions to the vehicle is accelerator pedal degradation is determined. The control actions may include adjusting a throttle position and adjusting vehicle brakes.

Provided is a control device for a vehicle including a continuously variable transmission. The control device includes a lock-up clutch, an oil pump, an electric motor, and a device control unit. The lock-up clutch is disposed in a torque converter coupled to the engine and switchable between an engaged state and a released state. The oil pump is driven by the engine and supplies a hydraulic oil to the continuously variable transmission. The electric motor is coupled to the engine and controlled to be in a powering state in which the engine is rotationally driven. The device control unit controls the lock-up clutch to put into the released state and controls the electric motor to put into the powering state if a discharge pressure of the oil pump falls below a threshold value at the time of a vehicle deceleration in which a fuel supply to the engine is cut off.

Lock-up clutch engagement hydraulic pressure learning control can be precisely performed by starting lock-up clutch engagement control and executing the lock-up clutch engagement hydraulic pressure learning control after execution of shift control is completed, in a case where the lock-up clutch engagement control is limited in a shift stage before execution of the shift control, when the shift control is executed in a state where a multi-disc lock-up clutch is released. Meanwhile, a decrease in fuel efficiency performance and a direct steering feeling is minimized by starting the lock-up clutch engagement control during shift control in a case where the lock-up clutch engagement control is not limited.

A vehicle includes: an internal combustion engine; a rotary electric machine; a connection-disconnection device; a hydraulic pressure supply device; a hydraulic pressure control device; and a control device. The hydraulic pressure supply device includes a mechanical hydraulic pressure supply device and a pressure accumulator. The control device executes fuel cut-off control to stop fuel supply to the internal combustion engine and rotation speed maintaining control to maintain a rotation speed of the internal combustion engine at a predetermined rotation speed by rotationally driving the internal combustion engine by the rotary electric machine or supplying fuel to the internal combustion engine. The hydraulic pressure control device supplies the hydraulic pressure to the connection-disconnection device by the pressure accumulator when the hydraulic pressure supplied to the connection-disconnection device by the mechanical hydraulic pressure supply device is less than a predetermined value when an acceleration command is given to the vehicle.

A control device for an automatic transmission includes a continuously variable transmission mechanism, a torque converter, a target transmission ratio calculation unit, a feedback control unit, and a phase compensation unit. The torque converter has a lock-up clutch. The target transmission ratio calculation unit is configured to calculate a target transmission ratio based on a travelling state. The feedback control unit is configured to perform feedback control based on an actual value indicative of a state of the continuously variable transmission mechanism. The phase compensation unit is configured to perform phase lead compensation of the feedback control based on the travelling state. The phase compensation control unit is configured to halt the phase lead compensation when an unstable travelling state of a vehicle is detected. The phase compensation control unit is further configured to release the lock-up clutch when the phase lead compensation is halted.

Methods and systems are provided for adjusting noise, vibration, and harshness (NVH) limits for a vehicle based on an occupancy level of the vehicle. The occupancy level is inferred based on a number of occupants and their position within a vehicle, and further based on a degree of interaction of a primary occupant with vehicle controls. As the occupancy level decreases, NVH constraints for operating the vehicle are reduced and one or more vehicle operating parameters nay be based on the reduced NVH constraints.