Dishwasher powers on and cycles, but no water enters the tub. Most likely a bad water inlet valve?
Verify that the water supply is on and there is good water pressure to the water inlet valve.
Make sure the float (#15 at the diagram) is moving freely up & down and it is in down position.
If there is nothing wrong, check the float switch (#11) for continuity. The normal reading should be about 0 Ohms.
If there is nothing wrong, remove the wires from the water inlet valve solenoid and check for 120 VAC between these wires while the control calls for water.
If the reading is correct, replace the water inlet valve.
Here are the breakdown diagrams and Replacement parts for Whirlpool KUDS25SHBS1 DISHWASHER | AppliancePartsPros.com
Gene.