Hybrid vehicle engine starts

Abstract

A vehicle includes a starter motor, an engine having an output mechanically coupled to the starter motor, a transmission having an input, and an electric machine mechanically coupled to the transmission input. The vehicle further includes a clutch configured to mechanically couple the electric machine and the output of the engine, and at least one controller. The at least one controller is programmed to initiate an engine start based on driver demand. The controller is further configured to enable pressure to the clutch for the engine start if driver demand is less than a calibratable torque value or enable the starter motor for the engine start if the driver demand is greater than a calibratable torque value. The controller may lock the clutch to the output of the engine in response to the speed of the engine being approximately equal to the speed of the electric machine.

Dependencies are inferred from the claim text.