Patent ID: 8409053

Claim:
A powertrain for a vehicle comprising: an engine; a transmission with an input member driven by the engine and an output member; an electric motor operatively connected to the input member and operable to drive the input member; an electrically-actuated one-way clutch having a neutral mode in which the clutch freewheels in both directions of rotation and a locked mode in which the clutch is locked in one direction of rotation; a hydraulically-actuated dual-piston clutch having a spring that mechanically-biases the dual-piston clutch to an engaged state without application of power; wherein the one-way clutch is in the neutral mode and the spring biases the dual-piston clutch to the engaged state prior to a key start of the engine so that torque is not transferred to the output member during ignition; wherein the one-way clutch is actuated to the locked mode following ignition of the engine after a key start, and remains in the locked state during an autostop of the engine, the locked one-way clutch and the spring establishing a first forward gear during an autostop without hydraulic or electric power.