Dish washer drain cycle wont complete

[warren3076]

First thing is we have a model number SHX5AL02UC which is very hard to find in any of the model listings that we have found on line. The problem with the machine is on starting the wash cycle the drain pump comes on to make sure the water is all out. But when the drain pump shuts off the next sound it makes sound like the drain pump is in reverse like its try to back flush. If we leave it alone it just shuts off and says clean. We found out that if you open and close the door then it would finish the cleaning cycle as normal. Now it has gotten to the point that every time it comes to a drain cycle it does this thing. I pulled the filters and every thing that is removable out of the inside of the machine, there was some junk just before it goes in to the drain pump, but i cleaned that out. I removed the drain pump and blew through the drain hose all seems ok.