Patent ID: 8100803

Claim:
An electrically variable transmission (EVT) for a vehicle, the EVT being operable for selectively establishing a plurality of transmission operating modes including a neutral mode and a plurality of EVT modes providing progressively higher speed/lower torque conditions, the EVT comprising: a source of pressurized fluid; a plurality of clutches each being selectively engagable using pressurized fluid from said source; a plurality of solenoid-actuated valves each configured to control a flow of said pressurized fluid to at least one of said plurality of clutches, said plurality of solenoid-actuated valves including: a first, a second, a third, and a fourth trim valve each selectively controlling an admission of said pressurized fluid into at least one of said plurality of clutches; and a first and a second blocking valve for selectively blocking an admission of said pressurized fluid into at least one of said first, second, third, and fourth trim valves, wherein one of said first and said second blocking valves is a latching device having a first and a second position; and an electronic control unit (ECU) operable for selectively actuating different combinations of said plurality of solenoid-actuated valves to thereby establish the plurality of transmission modes based at least partially on a speed of the vehicle; wherein said plurality of solenoid-actuated valves are configured to provide the EVT with multiple different default modes in the event of an electrical power failure at said ECU, said default modes including the neutral mode when said latching device is latched in the first position after said electrical power failure, and an EVT mode selected from the plurality of EVT modes that is established when the latching device is latched in the second position after said electrical power failure.