Collecting information for this site and others, I have now fixed my dishwasher that had (I think) a similar problem. Mine is a G646SC but that may not be important.
Symptoms
The dishwasher did not fill with water, the inlet/outlet light flashed.
Solution
Look inside the cabinet (where the dirty plates go), on your right there is an outlet, plastic grey circle. This may be loose. Remove this by unscrewing, clean (taking great CARE, I cut my finger on the stainless steel panel edge!), dry and screw firmly into place. This being loose will have caused the washing water to leak into the base pan of the machine (this is the very bottom of the unit). I accessed this by removing two screws inside the front of the machine that attach the lid, unscrew these, slide lid forwards and lift off. (We have UNPLUGGED - yes?) Next remove side panel (I removed both) by removing screws, one on side of front, two on top of side (exposed by removing lid) and one at bottom of back panel.
With sides removed I could mop up the water from the base pan, the machine no longer detected the leak and the machine has worked ever since (all of 1 day so far but I am confident of a clean future).
Good luck
JARK
November 2007