Hotpoint LFT 114 Strange Error

Hello, I own a Hotpoint LFT 114 dishwasher. The last months the dishes come out not perfectly clean. I ran the self test procedure (as advised by the service manual) and the dishwasher came up with the error 2. This error shows “CHARGING ELECTRO-VALVE BROKEN”. The thing is that it looks like working and completes the washing cycles and of course water isn’t entering the machine constantly (which would indicate a valve being constantly open). When the dishwasher is in washing cycle I can see water in the basin and as far as I can remember it looks like it is at the correct level.
Any ideas about the error? Is there a possibility that the machine takes less water than needed because of the valve and so the arms don’t have the correct pressure? That would explain the dirty dishes. On the other hand I guess that if it senses that it needs more water the valve will open to let more water in the machine. Or am I wrong?