Wheel speed sensor faults don't need clearing to get the light off the dash, although the fault will remain logged in the dtc memory as an intermittent/sporadic fault. Driving 20 yards in a straight line is enough to clear the light off the dash. As neil says above if the tracking is out more than about 3 degrees on any wheel it will put the light on, but that usually logs a fault code for the steering angle sensor not a wheel speed sensor.