we have the exact same model and the exact same thing happened. Turns out there was a tiny biy of the plastic packaging in the machine....looked like it wouldn't have stopped the machine running but it did!! if thats not it, then sorry i'm not very appliance friendly!!
We had the same problem (but with a Miele), it was also a piece of plastic. It was in the pump so we couldn't get at it ourselves... the service guy didn't charge us though (I'm sure he probably should have!)
How new is it, is it covered by guarantee?
If so contact your shop.
Also, Whirlpool products come with optional - FREE - 8 year parts warranty if purchased through an approved retailer but you must complete the registration card immediately, the details are with your manual