“WI” is so called economic… So he take water from prewash some seconds, wait a little, evacuate short, stay a little again and after he must take water until pressure switch say its enought.
It can be three things from me: like others said before valve solenoid or associated valve triac, EPROM. Change anyway pressostat (pressure switch) and clean PCB with one toothbrush and alcohol.
If you get in spin program does he move motor or not?.