Latching clutch valve control system

A system for a transmission in a motor vehicle, the system comprising:

• a pressure regulator subsystem that provides hydraulic fluid at variable pressures;
• a first clutch actuator;
• a second clutch actuator;
• a third clutch actuator;
• a valve assembly including:
• a valve body having an inlet in selective communication with an outlet and having an unlatch port, wherein the inlet is in communication with the pressure regulator subsystem and the outlet is in communication with the third clutch actuator;
• a latching piston disposed within the valve body and moveable between a first position and a second position;
• a balance spring disposed between the latching piston and the valve body;
• a valve piston disposed within the valve body, wherein the inlet communicates with the outlet when the valve piston is in a first position and wherein the inlet does not communicate with the outlet when the valve piston is in a second position;
• a diaphragm spring disposed between the latching piston and the valve piston wherein the diaphragm spring has a normal state that exerts force between the latching piston and the valve piston and an inverted state that does not exert a substantial force on the latching piston and the valve piston;
• a holding spring disposed between the valve piston and the valve body;
• an unlatching mechanism in communication with the first clutch actuator, the second clutch actuator, and the unlatch port,
• wherein when a pressure of the hydraulic fluid is less than a first threshold the diaphragm spring is in a normal state and moves the valve piston to the first position against the bias of the holding spring,
• wherein when a pressure of the hydraulic fluid is greater than the first threshold the latching piston moves to the second position and inverts the diaphragm spring;
• wherein when a pressure of the hydraulic fluid is less than the first threshold and the diaphragm spring is inverted the holding spring moves the valve piston to the second position, and
• wherein when a pressure of the hydraulic fluid is greater than a second threshold after the diaphragm spring is inverted and the valve piston is moved to the second position the diaphragm spring is returned to the normal state.