Whirlpool DU1145XTPQA - The Dishwasher runs its cycle properly, but the top rack looks like it didn't even get hit by water, often resulting in glasses and dishes being really greasy.
There is a pipe/tube that runs up the back of the inside of your dishwasher. This provides water for the top spray arm. The spray arm has a feeder tube that covers the pipe in the back. If for some reason the feeder tube has come dislodged, the water just drips back down into the dishwasher, never touching your upper shelf. My kids used to jam cutting boards and other large items into the lower shelf and in so doing, would dislodge the upper spray arm feeder tube. Just pull out the upper shelf and check to see that the tube is in the correct position. This should solve the problem.
If not, then the spray arm may have debris in it that keeps the water from being forced through the jets. You'll need to flush the arm with the spray attachment on your kitchen sink. I sometimes use tweezers or a toothpick to dislodge bits of peelings, paper, or bone that manage to get into the sprayer arm.
I hope one of these tips helps. If it does,please come back to fixya and rate my answer.