Abstract: An adaptive pressure control method for synchronous downshifts in an automatic transmission that uses pressure actuated friction elements. The method uses characteristic parameters that determine downshift quality for both power-on downshifts and power-off downshifts. Selected measured variables are monitored to detect changes in the parameters. Adjustments for the friction elements are made in response to changes in the measured variables.

Abstract: A hydraulic system for controlling the engagement and disengagement of a friction element includes a source of line pressure, a source of exhaust pressure, a manual valve having a forward state and a reverse state, connected to the exhaust pressure source and line pressure source and including a first outlet and a second outlet, for opening and closing communication between said outlets and said pressure sources in response to changes in the states, a friction element communicating with the line pressure source through the manual valve in the reverse state, and a control valve including a port communicating with the friction element, the control valve producing control pressure at the port when the manual valve is in the forward state.

Abstract: The present invention provides a fast learn algorithm for quickly providing data to a data table and a controller. Existing data is considered, such that information gathered from prior events is not arbitrarily overwritten. An error is determined for a first data cell based on current operating conditions and the occurrence of an event. Weighting factors are then applied to data cells removed from the first data cell, such that some or all of the data cells in the data table can be populated based on the data input into the first data cell.

Abstract: A method for controlling an automatic transmission in a vehicle is provided. The method selectively provides automatic engine braking for the vehicle. When it is determined that automatic engine braking is desired, the upshift schedule is increased, such that a higher vehicle speed is required to upshift for any given accelerator pedal position. The transmission is automatically downshifted to a lower gear to provide engine braking for the vehicle, when a vehicle acceleration threshold is exceeded. The automatic downshifting of the transmission can occur when the brake pedal is engaged, and when the brake pedal is disengaged.

Abstract: An adaptive shift control method for a geared multiple ratio transmission having friction elements for clutches and brakes to establish and disestablish gear ratio changes wherein at least one ratio change involves engagement of one friction element in synchronism with disengagement of another friction element. Operating parameters are adapted throughout the life of the transmission to reduce synchronous errors by developing and learning pressure and time adjustments for the friction elements.

Abstract: An adaptive shift control method for a geared multiple ratio transmission having friction elements for clutches and brakes to establish and disestablish gear ratio changes wherein at least one ratio change involves engagement of one friction element in synchronism with disengagement of another friction element. Operating parameters are adapted throughout the life of the transmission to reduce synchronous errors by developing and learning pressure and time adjustments for the friction elements.

Abstract: An adaptive pressure control method for synchronous downshifts in an automatic transmission that uses pressure actuated friction elements. The method uses characteristic parameters that determine downshift quality for both power-on downshifts and power-off downshifts. Selected measured variables are monitored to detect changes in the parameters. Adjustments for the friction elements are made in response to changes in the measured variables.

Abstract: A method for controlling an automatic transmission in a vehicle is provided. The method selectively provides automatic engine braking for the vehicle. When it is determined that automatic engine braking is desired, the upshift schedule is increased, such that a higher vehicle speed is required to upshift for any given accelerator pedal position. The transmission is automatically downshifted to a lower gear to provide engine braking for the vehicle, when a vehicle acceleration threshold is exceeded. The automatic downshifting of the transmission can occur when the brake pedal is engaged, and when the brake pedal is disengaged.

Abstract: The present invention provides a fast learn algorithm for quickly providing data to a data table and a controller. Existing data is considered, such that information gathered from prior events is not arbitrarily overwritten. An error is determined for a first data cell based on current operating conditions and the occurrence of an event. Weighting factors are then applied to data cells removed from the first data cell, such that some or all of the data cells in the data table can be populated based on the data input into the first data cell.

Abstract: A hydraulic system for controlling the engagement and disengagement of a friction element includes a source of line pressure, a source of exhaust pressure, a manual valve having a forward state and a reverse state, connected to the exhaust pressure source and line pressure source and including a first outlet and a second outlet, for opening and closing communication between said outlets and said pressure sources in response to changes in the states, a friction element communicating with the line pressure source through the manual valve in the reverse state, and a control valve including a port communicating with the friction element, the control valve producing control pressure at the port when the manual valve is in the forward state.