Dishwasher displays i40 and may stop mid-cycle or fail to start properly.

Safety first: Disconnect power before accessing internal components.

• Clean sump and filters: Remove and clean all filters. Use a soft brush to scrub the sump area where water collects, removing grease and scale that can affect pressure readings.
• Run a hot cleaning cycle: With the dishwasher reassembled, run the hottest program with a dishwasher cleaner or a cup of white vinegar in a dishwasher-safe container on the top rack to dissolve internal buildup.
• Inspect pressure hose (advanced): If accessible, locate the small rubber or plastic hose running from the sump/air chamber to the pressure sensor. Remove it and blow through it to clear blockages. Refit securely.
• Check wiring: Ensure the connector on the pressure sensor is firmly seated and free of corrosion.

If i40 persists after cleaning and hose inspection, the pressure sensor itself is likely faulty and should be replaced by a technician, as calibration may be required.