Whirlpool Washer Error F01: CCU / MCU Communication Fault

The Logic Verdict

My Take: On Duet/HE washers, F01 pops up when the CCU (top control) cannot talk to the MCU (motor control) or the drain system is stuck and the board panics. The video shows both failure modes: a clogged drain filter that prevented the machine from finishing, and a bad MCU. Always clean the filter before buying a $300 board.

What It Means

The F01 code stands for Primary Control Failure. The main brain of the washer isn’t talking to the motor.

Common Causes

1. Clogged Drain Filter: Triggers F01/F06 when the machine never reaches spin.
2. Loose Harness: Connectors between CCU (top) and MCU (bottom left) vibrate loose.
3. Failed MCU: Burned components stop the motor/communication.
4. Failed CCU: Corrupted relays or EEPROM on the main board.
5. Voltage Spikes: Surges damage the boards.

Step-by-Step Fix

1. Safety First: Unplug the appliance before performing any inspection.
2. Hard Reset: Leave unplugged for 5 minutes, then retry. Sometimes clears EEPROM glitches.
3. Clean the Drain Filter: Remove the lower panel (or rear access on pedestal models) and unscrew the pump filter. Remove coins, lint, socks, etc. Verify the impeller spins with slight magnetic “bumps.”
4. Inspect Wiring: Reseat the harnesses at the CCU (top rear) and MCU (bottom left). Look for burnt pins.
5. Test / Replace MCU: If the filter is clean and wiring is tight, the MCU is the usual culprit. Replace WPW10374126 (or your model’s equivalent) and retest.
6. Replace CCU: Only after MCU and wiring test good should you replace the CCU.

Resources

• Whirlpool Washer MCUs (Amazon)
• Whirlpool Duet Drain Pump Filters (Amazon)