Methods and system for starting an engine of a hybrid vehicle

摘要

Systems and methods for cranking an engine of a hybrid vehicle that includes an electric machine to crank the engine and propel the vehicle are disclosed. In one example, engine cranking speed and engine cranking source are selected in response to vehicle operating conditions that may affect whether or not an electrical power source has sufficient energy to crank the engine.

主权项

1. A driveline method, comprising:
in response to a first engine start request, adjusting a speed of an electric machine to a first speed and closing a driveline disconnect clutch; and in response to a second engine start request, adjusting the speed of the electric machine to a second speed, the second speed different than the first speed, adjusting the speed of the electric machine to a third speed after achieving the second speed, the third speed less than the second speed, and closing the driveline disconnect clutch during transitioning from the second speed to the third speed.