Dishwasher comes on but no water - KitchenAid 24 in. KUDP02CR Built-in Dishwasher

If there's no water entering your dishwasher, check these:

Water-inlet valve
Float switch
Water-inlet valve The water-inlet valve lets water enter the machine. If this valve is defective, you need to completely replace it. It's usually located behind the lower access panel on the left or right side. It's the device with the main water line (usually copper) from the house, a rubber tube to the dishwasher, and two wires attached to it.

Float switch The float switch is a small electrical switch that's located right below the dishwasher "floor." Above the switch, on the inside of the dishwasher, is a plastic cylinder that floats up as water fills the dishwasher. If this switch is defective, or if the plastic float gets caught or trapped in the raised position, the water can't enter the dishwasher. If the float switch is defective, you need to replace it.