A method of operating an automatic transmission of a motor vehicle, in which a hydraulic pump associated with a hydraulic system for the supply of pressure is driven by a drive motor. When the motor vehicle starts, a hydrodynamic starting element forms a driving connection between the drive motor and the automatic transmission. Hydraulic shifting elements (B1, B2, B3, C1, C2) are actuated for engaging gear steps. When the drive motor is started, a shifting element (B1, B2, B3, C1, C2) of the automatic transmission is engaged, and, during the engagement process of the shifting element (B1, B2, B3, C1, C2), a time of a rotational speed variation (n.sub.Ab, n.sub.Tu) of the automatic transmission is determined. With the help of the determined rotational speed variation (n.sub.Ab, n.sub.Tu), a time point is determined at which a pressure present in the hydraulic system reaches or exceeds a target pressure level.

A vehicle includes a hydraulic control unit (HCU) having a set of electrically-actuated valves configured to open/close to accumulate a pressurized hydraulic fluid in a hydraulic apply circuit of a first clutch of a transmission; a hydraulic fluid pump mechanically driven by an engine and configured to provide the pressurized hydraulic fluid to the HCU; and a controller configured to: prior to temporarily stopping the engine, control the engine and the HCU such that the pressurized hydraulic fluid accumulates in the hydraulic apply circuit of the first clutch to a desired hydraulic fluid pressure, and upon restarting the engine, control the set of electrically-actuated valves of the HCU to provide the pressurized hydraulic fluid from the hydraulic apply circuit first clutch to a hydraulic apply circuit for a second clutch of the transmission to apply the second clutch and shift the transmission into drive.

A vehicle propulsion system includes an engine including a crankshaft and adapted to generate torque, a crankshaft sensor that outputs a signal that is indicative of a rotary position of the crankshaft, a transmission with a clutch that is connected to the engine to receive the torque from the engine, a drive member connected to the transmission to receive torque from the transmission, and a controller that commands operation of the clutch based upon the signal from the crankshaft sensor for controlling engine compression pulse disturbances as the engine speed changes from an elevated rpm to low or zero rpm as well as low or zero rpm to an elevated rpm.

A powertrain includes an engine and a transmission. A vehicle includes a body structure and the powertrain supported by the body structure. The powertrain is configured to propel the body structure. The engine includes an output shaft, and the transmission includes an input member. The powertrain further includes a torque converter operable between the output shaft and the input member. The torque converter includes a pump and a turbine. The powertrain also includes a motor-generator operable as a motor and a generator. The input member of the transmission is connected to the turbine such that torque from the torque converter is transferrable to the input member. The input member of the transmission is coupled to the motor-generator such that torque is transferred between the input member and the motor-generator.

The present invention is configured such that: in a stopped state of an electric oil pump (M/O/P), control of the electric oil pump (M/O/P) is started such that, when a driver has the intention of demanding drive force, a discharge pressure takes on a target hydraulic pressure (P.sub.Th) determined in accordance with the demanded drive force from the driver; and a pressure regulation target value of a line pressure regulation valve (101) is set to a value that is higher than or equal to the target hydraulic pressure (P.sub.Th). Thus, it is possible to provide a vehicular hydraulic control device capable of suppressing hunting in line pressure (PL) when the line pressure (PL) is regulated so as to take on the target hydraulic pressure (P.sub.Th).

A transmission device is provided with a hydraulic control device, which has a pump for generating hydraulic pressure using power from a motor, and an accumulator, and which controls hydraulic pressure and supplies the hydraulic pressure to a hydraulic servo of an engagement element. The transmission device executes, when the motor that automatically stopped starts up with a request for vehicle travel: a fill control in which the hydraulic control device is controlled so that the hydraulic servo is being filled with working oil; a standby control to control the hydraulic pressure in the hydraulic servo at a standby pressure; and an engagement control to increase the hydraulic pressure in the hydraulic servo is started when the rotational speed of the motor becomes reaches or exceeds a prescribed rotational speed, after hydraulic pressure accumulated in the accumulator is released into the hydraulic circuit, so that the engagement element is engaged.

A method or system for controlling a vehicle having auto stop and auto start functions includes selectively inhibiting or disabling the auto stop or auto start functions in response to a detected vehicle position relative to an automatically learned vehicle route. The vehicle route is learned in response to previous drive cycles.

A method or system for controlling a vehicle having auto stop and auto start functions includes selectively inhibiting or disabling the auto stop or auto start functions in response to a detected vehicle position relative to an automatically learned vehicle route. The vehicle route is learned in response to previous drive cycles.

A method of controlling an automatic transmission mounted on a vehicle having an automatic engine stop mechanism for automatically stopping and restarting an engine, is provided. The transmission includes a piston having first and second surfaces, friction plates, engaging and disengaging hydraulic pressure chambers, a hydraulic pressure control valve for supplying/discharging hydraulic pressure to/from the chambers, first and second oil paths communicating the control valve with the chambers, a pressure reducing valve for preventing pressure of the disengaging chamber from exceeding a given set pressure, a hydraulic pressure supply device for supplying pressure to the control valve in the automatic stop state, and a mechanical oil pump for supplying pressure to the control valve while the engine is driving, the second surface having a larger pressure receiving area than the first surface. The method includes adjusting the set pressure to be lower in the automatic stop state than while driving.

The present disclosure provides a method for maintaining idle noise refinement in a vehicle. The method may include performing a D-range neutral control, wherein a controller is configured to apply auto hold threshold values to conditions for entering an auto hold control in a neutral control state, and wherein the auto hold threshold values are determinant of an entry into the D-range neutral control such that the auto hold threshold values limit the conditions for entering the auto hold control.