Method of controlling power transfer device for vehicle

A method of controlling a power transfer device for a vehicle, which comprises a traction motor that transfers power to auxiliary drive wheels of the vehicle comprising main and auxiliary drive wheels;

• a traction motor control unit that controls the traction motor;
• a case that rotates upon receiving the power generated from the traction motor;
• a first side gear that is connected to a first wheel of the auxiliary drive wheels;
• a second side gear that is connected to a second wheel of the auxiliary drive wheels;
• a pinion gear that meshes with the first side gear and the second side gear;
• a cage that supports the pinion gear and is configured to rotate relative to the case;
• a disconnect actuator system (DAS) that includes a lock plate supported by the case to come into contact with or be separated from the cage;
• a DAS controller that controls the DAS;
• a limited slip differential (LSD) that comprises a drum operatively connectable to the case, a first clutch disc coupled to the drum, a second clutch disc rotatable together with the second side gear, and a hydraulic device configured to engage and disengage the first clutch disc and the second clutch disc;
• and an LSD controller that controls the LSD, the method comprising performing sequence control for the traction motor control unit, the DAS controller and the LSD controller of the power transfer device.