A drive unit, method, and control system are provided that warm drive unit fluid in a drive unit having a main pump, a scavenge pump, and an electric motor for powering an axle of a vehicle. The control system and method are configured to fill a main sump of the drive unit with drive unit fluid to a predetermined fill level. In a warm-up mode, the method and control system operate the electric motor to heat the drive unit fluid within the main sump while the vehicle is stationary and the electric motor is at least partially disposed in the drive unit fluid within the main sump. Further in the warm-up mode, the method and control system are configured to operate the scavenge pump to pump the drive unit fluid from the main sump into an auxiliary reservoir after the drive unit fluid has been heated by the electric motor.