INDESIT WIE 137S SHOWING FAULT CODE F-04?

I HAVE AN INDESIT WASHING MACHINE APPROX 5 YEARS OLD SHOWING FAULT CODE F-04. MACHINE WAS COMING TO END OF CYCLE AND APPEARS TO HAVE 'JAMMED' BEFORE SPIN. ON OPENING DOOR SOME WATER REMAINING IN DRUM AND CLOTHES SOAKING WET. I BELIEVE THIS FAULT CODE IS SOMETHING TO DO WITH PRESSURE SWITCH BEING JAMMED ON EMPTY ???? IS THIS CORRECT AND WOULD IT BE EXPENSIVE TO FIX . ANY HELP MUCH APPRECIATED !