Thanks to hijoloo for pointing me in the right direction. The offending part is the diverter valve, a paddle inside blocks one of two outlets in turn actuated by a micro switch, a motor and reduction gears. Check switch for continuity with multimeter (ohms) then check motor and gears turn freely by hand. My problem was a stiff paddle due to limescale. Soak in boiling water to free off then oil cog (externally) and rebuild.

Turn the washer on its side and open up the bottom black plastic plate, than disconnect the two black hoses from the white pumphouse in the middle of the washer. disconnect the connector and open carefully the housing by removing two screws and the motor. check the switch and clean the white housing. Check also if there is nothing inside the rotorhouse. after this build every thing back and hope that its running. it worked for me. succes!