The 3 most common part(s) or condition(s) which cause the symptom Dishwasher doesn't clean are listed below starting with the most likely. Check or test each item and watch any available videos.
RepairClinic Item # 2309993
If the dishwasher won't clean dishes, it might not be getting enough water. There is an electrical valve called a water inlet valve which opens to allow hot water into the dishwasher. If this valve has failed or is clogged the dishwasher won't clean the dishes properly. The valve cannot be cleaned or repaired and should be replaced.
RepairClinic Item # 1263995
If the dishwasher won't clean dishes, check the lower wash arm assembly. If the lower wash arm isn't getting water, all of the dishes in the lower rack will come out dirty. Check to be sure the lower wash arm assembly spins freely. Also check to be sure the little holes in the lower wash arm aren't clogged or blocked.
RepairClinic Item # 1811038
If the dishwasher won't clean the dishes the pump and motor assembly might be defective. Once the dishwasher fills with water, the pump forces the water through the wash arms in order to spray the dishes. If the motor is defective, the pump impeller is broken, or some part of the pump is clogged, the dishes won't be clean. If the pump and motor has power to it and will not run it will need to be replaced.