How do you repair an F12 fault on a Hotpoint Aquarius WD440 washer/dryer?

Hi, I hope someone can help. I have some flashing lights on my Hotpoint Aquarius WD440 washer dryer when I turn it on. After some searching online I managed to find a list of error codes on this site. From the list I found it would appear I have an 'F12 - communication error' but I can't seem to find any suggestions on the cause or the cure of the problem. Is it likely to be a loose wire/connection/plug or is it more likely to be a pcb? Any help would be most welcome. Thanks in advance.