Washer displays F40 and will not start; communication error between main control and motor control on some models.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Loose or damaged communication harness, failed motor control board, failed main control board, electrical interference

Safety First: Unplug the washer before accessing controls.

Step-by-step checks:

1. Locate both boards: The main control is under the top; the motor control is near the base or rear.
2. Reseat harness: Disconnect and reconnect the communication harness at both ends. Inspect for corrosion or broken pins.
3. Inspect boards for damage: Look for burnt components or discoloration. Replace any obviously damaged board.
4. If wiring is good and no visible damage: Replace the motor control board first, then the main control if the error remains.

Hard 4/5

Motor Control Board

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