Dishwasher stops and shows F4; may fill but not wash properly.

Safety first: Shut off power and turn off the dishwasher’s water supply valve under the sink.

• Verify water supply: Confirm the shutoff valve is fully open. Check that other fixtures in the home have normal water pressure.
• Clean inlet screen: Disconnect the water supply line from the dishwasher inlet valve (place a towel or pan underneath). Inspect and clean the small screen inside the valve using a soft brush; do not puncture it.
• Test the inlet valve coil: With power off, disconnect the wiring harness from the valve. Measure coil resistance with a multimeter; an open reading indicates a failed valve that must be replaced.
• Check for kinks: Inspect the supply line for kinks or crushing that could restrict flow. Replace damaged lines.

After reassembly, restore power and water, then run a fill test. If F4 persists with good pressure and a new valve, the control board may be at fault.