METHOD AND APPARATUS FOR CONTROLLING A POWERTRAIN SYSTEM

A powertrain system configured to transfer torque to a driveline is described, and includes an internal combustion engine, a torque converter, a transmission, an electric machine, and a controller. The engine is configured to operate in one of an all-cylinder mode and a dynamic deactivation mode to generate an engine torque. The electric machine is configured to generate a motor torque. The motor torque and the engine torque combine to generate an output torque that is transferable to the driveline and is responsive to an output torque request. The controller is in communication with the engine, the torque converter, the transmission, and the electric machine. The controller includes an instruction set that is executable to operate the engine in the dynamic deactivation mode to generate engine torque, and operate the electric machine to generate motor torque to supplement the engine torque to generate the output torque.