Abstract: A control method for a hybrid powerplant includes receiving a pre-transition signal, and selectively adjusting a combustion torque of an engine of the powerplant between a first torque value and a second torque value prior to a deactivation transition period based on the pre-transition signal, wherein the second torque value is less than the first torque value. The method further includes selectively adjusting an electric drive torque of an electric machine of the powerplant prior to the deactivation transition period based on the pre-transition signal and the combustion torque. The selectively adjusting the electric drive torque includes adjusting the electric drive torque such that a sum of the combustion torque and the electric drive torque is equal to a desired drive torque of the powerplant during a pre-transition period prior to the deactivation transition period. A related control system is also provided.

Abstract: An engine control system of a vehicle comprises a torque module and a chassis request evaluation module. The torque module controls a torque output of an engine based on a driver torque request and selectively increases the torque output based on a chassis torque request. The chassis request evaluation module selectively prevents the increase of the torque output based on at least one of a vehicle speed, a transmission state, and an accelerator pedal position.

Abstract: A control system for a hybrid vehicle including an engine with cylinder deactivation comprises an engine time off module that determines an engine time off value. A re-purge determining module estimates a re-purge time required to purge a hydraulic control system of the engine of air before initiating cylinder deactivation. The re-purge time is estimated based on the engine time off value and an engine temperature.

Abstract: An engine control system comprises a torque control module and a fueling control module. The torque control module selectively generates a deactivation signal for a first cylinder of a plurality of cylinders of an engine based on a torque request. The fueling control module halts fuel delivery to the first cylinder based on the deactivation signal. The torque control module increases a spark advance of the engine at a first time after the fueling control module halts fuel injection for the first cylinder. The first time corresponds to an initial time combustion fails to occur in the first cylinder because fuel delivery has been halted.

Abstract: A leak detection system for a vehicle fuel tank includes a sensor that is responsive to a pressure within the fuel tank and that generates a pressure signal based thereon. A control module initiates an engine-off natural vacuum (EONV) test and determines a pressure change based on the pressure signal. The control module pauses the EONV test when the pressure change exceeds a pressure change threshold.