Dishwasher displays U3; unit may not start or may stop with rack-related issues.

Safety first: No electrical work is needed initially; keep power connected for testing.

• Check rack position: Ensure the upper rack is fully pushed in and locked into one of the designated height positions.
• Inspect rack tracks: Look for obstructions or damage to the rack rails and wheels. Repair or replace damaged wheels or clips.
• Reset cycle: Cancel the current cycle and restart with racks properly seated.
• If U3 persists: On models with rack position sensors, the sensor or wiring may be faulty and require professional service.