ESTIMATION OF VEHICLE SPEED IN ALL-WHEEL-DRIVE VEHICLE

A vehicle includes an all-wheel-drive powertrain having an electric machine configured to power wheels. A controller is programmed to output a first calculated vehicle speed derived from integrating a measured longitudinal acceleration of the vehicle and output a second calculated vehicle speed based on the measured longitudinal acceleration and a speed of one of the wheels. The controller is further programmed to, responsive to a flag being present, command a speed to the electric machine that is based on the first vehicle speed to reduce wheel slip, and responsive to a flag not being present, command a speed to the electric machine that is based on the second vehicle speed to reduce wheel slip.