Patent ID: 8276555

Claim:
A method for operating a hybrid powertrain system including an internal combustion engine and a torque machine for transferring torque to a driveline in response to an operator torque request, the engine having two-step variable lift control mechanisms for controlling magnitude of valve lift of intake and exhaust engine valves to one of two discrete steps including low-lift valve open positions and high-lift valve open positions, the method comprising: commanding a switch of the two-step variable lift control mechanism between a first of the two discrete steps and a second of the two discrete steps during engine operation; upon commanding the switch, commencing a fuel cut-off event in the direct injection internal combustion engine, switching the two-step variable lift control mechanism from the first of the two discrete steps to the second of the two discrete steps, and then restarting the direct injection internal combustion engine; and during the fuel cut-off event for the direct injection internal combustion engine, operating the torque machine to transfer torque to the driveline responsive to the operator torque request.