Abstract: A hydraulic control system for a transmission of a motor vehicle includes a source of pressurized hydraulic fluid that communicates with an analog electronic transmission range selection (ETRS) subsystem or a manual valve. The ETRS subsystem includes an ETRS valve, a park servo, a park mechanism, a mode valve, and a plurality of solenoids. The ETRS and manual valve communicate with a clutch actuator subsystem that engages a one-way clutch and six clutches/brakes.

Abstract: A multiple plate friction clutch includes clutch plates or discs having reduced frictional (spin) losses and thus reduced heat generation and improved service life. The clutch plates include both leaf springs or spring tabs at the periphery of the clutch plate that axially bias adjacent plates away from one another and a reduced area of friction material that contacts an adjacent reaction plate. On a typical motor vehicle automatic transmission clutch, a total of six or eight leaf springs or tabs are utilized: with three or four offset to one side and three or four offset to the other side.

Abstract: A hydraulic control system for a transmission includes a source of pressurized hydraulic fluid that communicates with an electronic transmission range selection (ETRS) subsystem. The ETRS subsystem includes an ETRS valve, a park mechanism, a mode valve, a latch valve assembly, and a plurality of solenoids. The ETRS subsystem is configured to provide desired operating conditions during a plurality of potential failure conditions.

Abstract: A method of preventing an automatic engine stop includes: determining a pressure difference between an accumulator fill volume and a fluid conduit in selective fluid communication with the accumulator fill volume; determining a change in the accumulator fill volume from the determined pressure difference; adding the change in the accumulator fill volume to a previous estimate of the accumulator fill volume to determine a current estimate of the accumulator fill volume; comparing the current estimate of the accumulator fill volume to a predetermined threshold; and preventing an automatic engine stop if the current estimate of the accumulator fill volume is below the predetermined threshold.

Abstract: A system for locking a Park device in a transmission in an out-of-Park mode of operation includes a valve body that defines a bore, a solenoid connected to the valve body, a lock feature disposed in the valve body and interconnected with the solenoid, and a servo piston disposed within the bore of the valve body. The servo piston has a detent and the servo piston is interconnected to the Park device and is moveable between a first position and a second position. The detent is radially aligned with the lock feature when the servo piston is in the first position. Activation of the solenoid locks the lock feature into the detent of the servo piston to lock the Park device of the transmission in the no-Park mode.

Abstract: A multiple plate friction clutch includes clutch plates or discs having reduced frictional (spin) losses and thus reduced heat generation and improved service life. The clutch plates include both leaf springs or spring tabs at the periphery of the clutch plate that axially bias adjacent plates away from one another and a reduced area of friction material that contacts an adjacent reaction plate. On a typical motor vehicle automatic transmission clutch, a total of six or eight leaf springs or tabs are utilized: with three or four offset to one side and three or four offset to the other side.

Abstract: A hydraulic control system of an automatic transmission includes a clutch compensator feed circuit that is in communication with clutch apply circuit exhaust fluid. The clutch compensator feed circuit receives exhaust fluid from one or more apply clutches, or other torque transmitting device(s), and feeds the exhaust fluid to the balance side of the clutch or other torque transmitting device. The clutch compensator feed circuit may be open to atmospheric pressure, such that the clutch compensator feed circuit is not pressurized with respect to atmospheric pressure.

Abstract: A torque converter hydraulic control subsystem for a transmission is provided. The torque converter hydraulic control subsystem includes a source of pressurized hydraulic fluid that communicates with a torque converter clutch (TCC) regulation valve, a TCC control valve, and a lubrication boost valve. The torque converter hydraulic control subsystem is configured to provide cooling and lubrication fluid flow to a torque converter in all modes of operation.

Abstract: A hydraulic control system for a transmission includes a source of pressurized hydraulic fluid that communicates with an electronic transmission range selection (ETRS) subsystem or manual valve and a clutch actuation subsystem.

Abstract: A hydraulic control system for a transmission includes a sump tank, a front cover, a wall, and a flow control valve. The sump tank is attached to a bottom end of the transmission. The front cover includes an overflow tube and a hydraulic fluid input. The wall hydraulically separates the sump tank and the front cover. The flow control valve is disposed in the wall between the sump tank and front cover. The flow control valve is open when the transmission is going through an extreme maneuver and requires a greater amount of hydraulic fluid in the sump tank and the flow control valve is closed during normal transmission operation.

Abstract: A hydraulic control system for a transmission of a motor vehicle includes a source of pressurized hydraulic fluid that communicates with an analog electronic transmission range selection (ETRS) subsystem or a manual valve. The ETRS subsystem includes an ETRS valve, a park servo, a park mechanism, a mode valve, and a plurality of solenoids. The ETRS and manual valve communicate with a clutch actuator subsystem that engages a one-way clutch and six clutches/brakes.

Abstract: A hydraulic control system for a transmission includes a source of pressurized hydraulic fluid that communicates with an electronic transmission range selection (ETRS) subsystem. The ETRS subsystem includes an ETRS valve, a park mechanism, a mode valve, a latch valve assembly, and a plurality of solenoids. The ETRS subsystem is configured to provide desired operating conditions during a plurality of potential failure conditions.

Abstract: A hydraulic control system for a transmission is provided. The hydraulic control system includes a source of pressurized hydraulic fluid that communicates with a discrete electronic transmission range selection (ETRS) subsystem. The hydraulic control system includes first and second mode valves located downstream of a hydraulic fluid pressure source. The mode valves are supplied with fluid via one or more solenoid valves or other valves. The mode valves have a plurality of ports configured to transfer pressurized hydraulic fluid. The first mode valve transfers pressurized hydraulic fluid from the source to the second mode valve. The second mode valve transfers pressurized hydraulic fluid from the first mode valve to one of drive or reverse. An electro-hydraulic circuit for pulling the transmission out of park and putting the transmission into park is also provided. A park sensor assembly including a Hall Effect sensor switch is also provided.

Abstract: A control system for a transmission includes a pressure control module and a pressure adapt module. The pressure control module operates a hydraulic control system of the transmission at a target pressure during steady-state operation of the transmission. The target pressure is based on first and second learned pressures for different predetermined first and second torque ranges. The pressure adapt module selectively adjusts at least one of the first learned pressure and the second learned pressure based on a first pressure at which a slip condition of the transmission occurs. The first and second learned pressures define a learned pressure gain and offset. When adjusting the first and second learned pressures, the pressure adapt module limits increases and decreases in the learned pressure gain offset based on a predetermined pressure gain and offset. A method is also provided.

Abstract: A method of filling a clutch chamber of an automatic transmission includes determining an engage pressure to engage a clutch of the automatic transmission. The method determines a reactive pressure of a return spring of the clutch. The method also estimates a fill pressure based on the engage pressure and the reactive pressure. The method estimates a flow rate based on the engage pressure, and generates a fill pressure command signal to fill the clutch chamber based on the fill pressure, the flow rate and a flow rate limit.

Abstract: A control system for a transmission includes a pressure control module and a pressure adapt module. The pressure control module operates a hydraulic control system of the transmission at a target pressure during steady-state operation of the transmission. The target pressure is based on first and second learned pressures for different predetermined first and second torque ranges. The pressure adapt module selectively adjusts at least one of the first learned pressure and the second learned pressure based on a first pressure at which a slip condition of the transmission occurs. The first and second learned pressures define a learned pressure gain and offset. When adjusting the first and second learned pressures, the pressure adapt module limits increases and decreases in the learned pressure gain offset based on a predetermined pressure gain and offset. A method is also provided.

Abstract: A method of filling a clutch chamber of an automatic transmission includes determining an engage pressure to engage a clutch of the automatic transmission. The method determines a reactive pressure of a return spring of the clutch. The method also estimates a fill pressure based on the engage pressure and the reactive pressure. The method estimates a flow rate based on the engage pressure, and generates a fill pressure command signal to fill the clutch chamber based on the fill pressure, the flow rate and a flow rate limit.

Abstract: An integral stand tube for regulating fluid level within a transmission is provided. The stand tube includes an upper opening, at least one lower opening, and an internal volume defined by at least one internal passage for directing fluid from a valve body-side of a transmission to a main sump located on a gear-side of the transmission. The lower opening is operatively connected to a thermal valve assembly and a fluid passage formed in the transmission case between the auxiliary sump of the valve body-side and the main sump of the gear-side. Fluid passing from auxiliary sump to main sump bypasses dynamic transmission components to thereby minimize fluid aeration due to contact therebetween.

Abstract: A thermal valve assembly for a transmission is provided. The thermal valve assembly includes a body having a base portion having a plurality of opposing sidewalls extending therefrom. A cover is mounted with respect to the body and operates to at least partially close the body to form a volume. The base portion defines an inlet orifice, while at least one of the plurality of opposing sidewalls at least partially defines an outlet orifice. A plate is operable to selectively close the inlet orifice. A bi-metallic spring member is disposed at least partially within the volume. The bi-metallic spring member is operable to bias the plate against the base portion. Additionally, the bi-metallic spring member has a variable stiffness characteristic responsive to temperature.

Abstract: An integral stand tube for regulating fluid level within a transmission is provided. The stand tube includes an upper opening, at least one lower opening, and an internal volume defined by at least one internal passage for directing fluid from a valve body-side of a transmission to a main sump located on a gear-side of the transmission. The lower opening is operatively connected to a thermal valve assembly and a fluid passage formed in the transmission case between the auxiliary sump of the valve body-side and the main sump of the gear-side. Fluid passing from auxiliary sump to main sump bypasses dynamic transmission components to thereby minimize fluid aeration due to contact therebetween.