Patent ID: 8490640

Claim:
A system for regulating pressure supplied to a transmission control element, comprising: a control pressure source; a line pressure source; a latch valve including a first spool, to which is applied a force of a first spring tending to close first communication with the line pressure source, and a first control pressure force produced by the control pressure source tending to open the first communication; and a regulator valve including a second spool to which is applied a force of a second spring, and a control element feedback pressure force tending to close a second communication between line pressure and the control element, and a second control pressure force produced by the control pressure source tending to open the second communication when the latch valve is opened and closed, and an auxiliary piston transmitting to the second spool a force of a third spring and a line pressure force tending to open the second communication when the first communication is open, the control element feedback pressure remaining pressurized when the second communication is opened and closed.