Method for reducing torque required to crank engine in hybrid vehicle

A method of operating a hybrid powertrain system for a hybrid vehicle that includes an internal combustion engine having an engine output to drive the vehicle and an electric motor having a motor output to drive the vehicle, the electric motor operatively connected to the engine and operable to crank the engine, the method comprising the steps of:

• determining whether the electric motor is capable of cranking the internal combustion engine;
• reducing compression in at least one engine cylinder if the motor is incapable of cranking the internal combustion engine;
• operating the electric motor to crank the engine to a predetermined speed or according to a target speed profile;
• increasing compression in the at least one engine cylinder when the predetermined speed or target speed profile is achieved;
• fueling the engine;
• and
• discontinuing operation of the electric motor after the internal combustion engine starts.