Vehicle and method for controlling engine start in a vehicle

A method for starting an engine in a vehicle having a transmission, an accelerator, an electric machine, a first clutch disposed between the engine and the electric machine for selectively connecting the engine to the electric machine, and a second clutch disposed between the electric machine and vehicle drive wheels, the second clutch being selectively engagable for facilitating torque transfer between the electric machine and the vehicle drive wheels, the method comprising:

• requesting an engine start;
• operating the electric machine;
• determining a start mode for the engine based at least in part on at least one of a position of the accelerator and a current transmission gear, a first engine start mode including the transmission gear being first gear or higher, and the accelerator position being at least partially open;
• and
• facilitating slip in the second clutch when it is determined that the engine is in the first start mode when the engine start is requested, the facilitation of slip in the second clutch being effective to at least partially isolate the vehicle drive wheels from engine torque disturbances;
• engaging the first clutch, thereby connecting the engine to the electric machine;
• and
• fueling the engine, thereby facilitating torque production by the engine.

A vehicle including vehicle drive wheels, the vehicle comprising:

• an engine;
• a transmission;
• an electric machine operable to propel the vehicle and to rotate the engine;
• a first clutch disposed between the engine and the electric machine for selectively connecting the engine to the electric machine;
• a second clutch disposed between the electric machine and the vehicle drive wheels, the second clutch being selectively engagable for facilitating torque transfer between the electric machine and the vehicle drive wheels;
• and
• a control system including at least one controller, the control system being configured to request an engine start, operate the electric machine, and facilitate slip in the second clutch if the transmission is in first gear or higher when the engine start is requested, the facilitating of slip in the second clutch being effective to at least partially isolate the vehicle drive wheels from engine torque disturbances, the control system being further configured to engage the first clutch, thereby connecting the engine to the electric machine, and to fuel the engine, thereby facilitating torque production by the electric machine.