The upper rack will not clean the dishes the lower one work ok

Not knowing what dish washer you have I would check on the sprayer make sure it turns or is not blocked in any way. If the water can't spray up you will not get clean dishes.

Make sure that that upper arm is free to turn. Check it while you have dished installed, because sometimes, dishes on the lower rack may stick up too high and hit it. Otherwise, check the back of the water-supply tube attached to that upper rack.... Is it lining up with the water feed port or hole at the backof the dishwasher? Is there a gasket that is either ripped or missing? And check that wash arm carefully.... Might it be split or bent? Are the holes on the bottom clear? (Those holes are usually angled to push the arm around; if they are clogged, the arm won't rotate.)

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Lower Rack

• Remove all of the dishes from the lower dishwasher rack.
• Pull the lower rack out of the dishwasher so that it rests on the dishwasher door.
• Lift the lower rack up and out of the dishwasher.
• Place the new lower dishwasher rack on the dishwasher door, then push it into the dishwasher.
• Upper Rack
• Remove all of the dishes from the lower dishwasher rack.
• Extend the upper rack as far as it will go.

Remove the two plastic end caps, located on the end of each dishwasher arm. To remove, insert a flat-head screwdriver between the arm and the tab on the outside of the end cap, then lift the tap to remove the end cap.
Pull the upper dishwasher rack straight of out the arms to remove.

Insert the rollers on the bottom of the new upper dishwasher rack into the rack arms, then push the rack completely into the dishwasher.
. Align the end caps with the ends of the arms, then push the end caps into place.

Upper Rack

• Remove all of the dishes from the lower dishwasher rack.
• Extend the upper rack as far as it will go.
• Remove the two plastic end caps, located on the end of each dishwasher arm. To remove, insert a flat-head screwdriver between the arm and the tab on the outside of the end cap, then lift the tap to remove the end cap.
• Pull the upper dishwasher rack straight of out the arms to remove.
• Insert the rollers on the bottom of the new upper dishwasher rack into the rack arms, then push the rack completely into the dishwasher.
• Align the end caps with the ends of the arms, then push the end caps into place.

Check all the water jet orfices in the moving arm. Try cleaning without loading the top rack.

If cleans well, mostly the upper rack dishes not arranged properly.

I hope you are using the main wash detergents. Rinse aid is just to remove the stains after the main wash rinse.

try c.l.r. to clean dishwasher check and clean lower and upper spray arms out, run no detergent you can also run vinegar in it as well about a cup full,let the machine start to run then stop dish washer for a few hours then restart see if this works for you use a short cycle.

ok so If your dishwasher has worked fine in the past but, suddenly, your dishes aren't clean after the dishwasher completes all cycles:
1) Check your water heater's temperature dial to be sure it hasn't been changed recently.
2) Be sure dishes haven't prevented the detergent dispenser from opening properly during the wash cycles or kept the spray arms from turning, the lower arm from rising, or the spray from reaching the upper rack's dishes.
3) During the wash cycle, listen to the spray arm spinning inside. If it seems to be spinning poorly, clean out the spray holes in the spray arm(s) with a stiff piece of wire; wait for the machine to cool, and then remove the spray arm(s) by unscrewing the hub cap and lifting the arm(s) off Regards Gizokieth

Check the upper arm for free spinning, then remove the arm and check that the seam between the upper and lower halves has not split somewhere. Also check all the small holes for debris plugging. Run the machine in wash cycle for a little while with the upper arm off--that should flush out anything blocking the pipe up to the arm. If still nothing from the upper arm, tear down the lower arm assembly down to the deck while noting position of all parts removed. Clean the big screen at the bottom in white vinegar and hot water. Inspect the holes in the bottom for anything blocking them.

Yes there is the Water Div valve, it diverts the water between the wash arms.

Sounds like the hose assembly that attaches to the rear of the upper rack has come undone. just pull out the upper rack and reconnect it.

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id try removing hte lower filter plate . 5 torx 15 screws will gain oyou acess to lower sump and 2 more torx screws that will acess you the chopper assy, prhaps filled with debris not allowing good water flow,