A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

An electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control when shift control is performed during the performance of lockup control, the electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control. Besides, the electronic control unit places priority on the shift control and starts the lockup initial oil pressure control after the completion of the shift initial oil pressure control, when the lockup control is performed during the performance of the shift control. Therefore, the shift initial oil pressure control and the lockup initial oil pressure control are prevented from occurring at the same time when the shift control and the lockup control are performed at the same time.

In the case where the lockup clutch is in the complete engagement state when a changeover between shift stages is made with the second shift mode selected, an electronic control unit holds the lockup clutch in the complete engagement state. Meanwhile, in the case where the lockup clutch is in the slip engagement state, the electronic control unit holds the lockup clutch in the slip engagement state based on a slip amount of the torque converter, or switches the lockup clutch to the complete engagement state.

A vehicle control device is configured to execute a fuel cut control for stopping fuel supply to an internal combustion engine in response to a deceleration request to a vehicle; disengage a lock-up clutch and open a throttle of the vehicle during execution of fuel cut control; execute motor assist in a case where there is an acceleration request to a vehicle while the lock-up clutch is disengaged and the throttle is opened; and execute a motor torque reduction control for temporarily reducing an output from an electric motor based on a rotation speed of the internal combustion engine and a rotation speed of a main shaft during the execution of the motor assist.

A vehicle control device is configured to: execute a fuel cut control for stopping fuel supply to the internal combustion engine in response to a deceleration request to the vehicle; engage the lock-up clutch and open a throttle of the vehicle during the execution of the fuel cut control; close the throttle and execute the motor assist in a case where there is an acceleration request to the vehicle while the lock-up clutch is engaged, the throttle is opened, and the fuel cut control is executed; end the fuel cut control and resume fuel supply to the internal combustion engine when an intake pressure of the internal combustion engine reaches a predetermined startable negative pressure after the throttle is closed; and disengage the lock-up clutch when the fuel supply to the internal combustion engine is resumed.

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.

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.