ER is membrane switch failure--main control has detected a stuck key or a key pressed for more than one minute. UO is vent open--While in wash cycle, Main Control Board does not receive signal
from vent assembly that vent plunger is closed. Plunger status is sensed with optical sensor in vent assembly. Check wiring between vent assembly and Main Control Board. If wiring correct, replace vent assembly. If error still exists, replace Main Control Board.