Patent ID: 7322899

Claim:
An electro-hydraulic control system for an electrically variable hybrid transmission having a plurality of torque transmitting mechanisms, said electro-hydraulic control system comprising: a main source of pressurized fluid; an electrical source of electrical control signals; a first trim valve and a second trim valve each having a first position and a second position and in selective fluid communication with said main source, said first trim valve and said second trim valve being operable to output fluid pressure when said first trim valve and said second trim valve are in said second position and to discontinue output of fluid pressure when said first trim valve and said second trim valve are in said first position; wherein said first trim valve and said second trim valve are biased to said second position when said electrical source is inoperable; a first logic valve in selective fluid communication with said second trim valve and operable to receive pressurized fluid from said second trim valve; and a second logic valve disposed to selectively receive pressurized fluid from said first logic valve and said first trim valve, said second logic valve being operable to selectively engage one of a first and a second of said plurality of torque transmitting mechanisms.