In a powertrain that includes wheels for driving a vehicle, a crankshaft, a machine driveably connected to the crankshaft and able to operate alternately as an electric motor and electric generator, a transmission including an input clutch driveably connected to the crankshaft and an output driveably connected to the wheels, a method for controlling idle speed including producing a desired magnitude of input clutch torque capacity, producing a desired wheel torque, using an error represented by a difference between a desired crankshaft idle speed and a current crankshaft speed to determine a desired change in torque produced by the machine, using the magnitude of input clutch torque capacity and the desired change in torque produced by the machine to determine a desired magnitude machine torque, and using the machine to produce said desired magnitude of machine torque.