starts OK and fills to start washing to then stop, by moving control knob it restarts and washers for several minutes to again stop requiring another manual movement of the control knob where it pumps out, it then refills to wash but stops almost immediately.
Could be any one of a number of reasons. Faulty timer, faulty wiring, not enough water in sump. leak or blockage on the pressure switch air hose. Just to name a few. You really need someone there to check it and fault find with a multimeter when the fault occurs.