Method for controlling internal combustion engines in hybrid powertrains

A method for selectively creating vacuum in a hybrid powertrain controlled by a hybrid control processor and having an engine controlled by an engine control module, the method comprising:

• requesting a pressure differential between a first intake point and a second intake point, wherein the first intake point is an air intake for the engine, the second intake point is a manifold for the engine, and the first intake point and the second intake point are separated by a throttle;
• monitoring a powertrain torque request;
• calculating an actual torque capacity for the engine, wherein the actual torque capacity occurs when pressure is substantially equal at the first intake point and at the second intake point;
• calculating a desired torque capacity for the engine, wherein the desired torque capacity reduces the pressure at the second intake point relative to the pressure at the first intake point, such that the requested pressure differential is created;
• sending the actual torque capacity and the desired torque capacity to the hybrid control processor;
• comparing the powertrain torque request to the actual torque capacity and the desired torque capacity with the hybrid control processor;
• determining an engine torque request with the hybrid control processor, wherein determining the engine torque request, includes:
• operating the engine at the desired torque capacity if the powertrain torque request can be met with the desired torque capacity, and
• operating the engine between the desired torque capacity and the actual torque capacity if the powertrain torque request cannot be met with the desired torque capacity;
• and
• sending the engine torque request from the hybrid control processor to the engine control module.