How to fix Hoover Soft Wave washing machine?

The washing machine stops mid cycle, full of water, its has the door lock light lit and the start and intensive wash lights flash together. We have checked and emptied the front filter (yes full of coins). We have also checked the hose for a blockage. Last night I ran a 90degree wash with the machine empty and this worked fine, I thought the problem was solved but the problem is back. I can drain off the water selecting the drain water function. Can anyone out there help, the machine is only 2 years old. Thanks