WFW9400SW00 how to check mcu

F11 is a serial communication error. Communication between the main board and the motor control board is not being sent correctly. This could be a bad main board, motor control board or motor itself. The testing can get pretty involved. Try putting the machine in a self test mode and see if the error clears. Press Cancell, then by pressing the drain spin button once on the left side then move to the spin speed button the the right. Press this button until no-spin lights. Press the prewash button 4 times. C00 should appear in the display. Let it run it's tests, there will be 8 of them and end up on C08.this is for the 4t
for the 3t:
Communication between the Central Control Unit (CCU) and the Motor Control Unit (MCU) cannot be sent correctly.

Potential Causes

• Check Wire Harness connections to the MCU, the motor, and Central Control Unit (CCU)
• Check the Drive system for any worn or failed components
• Check MCU
• Check CCU
• Check Motor
• Check Wire Harness

Replace failed component.
hope this helps 90 percent of the time it is a failed ccu

1. Unplug washer or disconnect from power.
2. Check wire harness between drive motor and MCU. Between MCU and CCU. Check the motor and do a continuity test.
3. Plug in washer or reconnect power.
4. Check the MCU by looking for operations of the drive motor.
5. Check the drive motor for powered rotations.
6. Replace the MCU board.

F07 - Motor Control Unit (MCU) Error - Disconnect power and unplug unit. Check wire harness connections between drive motor and Motor Control Unit (MCU), and between MCU and the Central Control Unit (CCU). Reconnect power and plug unit in.
Check the MCU by looking for operations of the drive motor, and check drive motor for powered rotations. Replace failed component.

Note: If this failure occurs during high-speed spin, the door will be unlocked after three minutes.

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This is a Drive Motor Tachometer Error. The control is unable to properly detect motor speed and the machine will shut down. If a failure occurs during high-speed spin, the door will be unlocked after 3 minutes.

Make sure the wash load is not too heavy and do not move the washer when it is powered on.

If the error persists then the normal process is to check the following:

1. Check wire harness connections between the Drive Motor/Tachometer and the Motor Control Unit (MCU), and between the MCU and the Central Control Unit (CCU).
2. Check the Drive Motor.
3. Check the MCU
4. Check the Wire Harness

F07 - Motor Control Unit (MCU) Error - Disconnect power and unplug unit. Check wire harness connections between drive motor and Motor Control Unit (MCU), and between MCU and the Central Control Unit (CCU). Reconnect power and plug unit in.
Check the MCU by looking for operations of the drive motor, and check drive motor for powered rotations. Replace failed component.

Note: If this failure occurs during high-speed spin, the door will be unlocked after three minutes.

Thanks for using FixYa - a 4 THUMBS rating is appreciated for answering your FREE question

Error F06 is Drive Motor Tachometer Error
The control is unable to properly detect motor speed and the machine will shut down. If a failure occurs during high-speed spin, the door will be unlocked after 3 minutes. Check wire harness connections between the Drive Motor/Tachometer and the Motor Control Unit (MCU), and between the MCU and the Central Control Unit (CCU)

• Check the Drive Motor
• Check the MCU
• Check the Wire Harness

F11 is a serial communication error. Communication between the main board and the motor control board is not being sent correctly. This could be a bad main board, motor control board or motor itself. The testing can get pretty involved. Try putting the machine in a self test mode and see if the error clears. Press Cancell, then by pressing the drain spin button once on the left side then move to the spin speed button the the right. Press this button until no-spin lights. Press the prewash button 4 times. C00 should appear in the display. Let it run it's tests, there will be 8 of them and end up on C08. If this doesn't work, it's best you wait for the service tech.


Good luck

hello Serial Communication Error
Communication between the Central Control Unit (CCU) and the Motor Control Unit (MCU) cannot be sent correctly.

• Check Wire Harness connectors to the MCU, the motor, and Central Control Unit (CCU)
• Check the Drive system for any worn or failed components
• Check MCU
• Check CCU
• Check Motor
• Check Wire Harness
• shaun

F 07
The main control has detected a short in the Motor Control
Unit. If a failure occurs during high-speed spin, the door
will be unlocked after three minutes.

Possible Causes / Procedure
1. Unplug washer or disconnect power.
2. Check wire harness connections between the drive
motor and the Motor Control Unit (MCU), and between
the MCU and the Central Control Unit (CCU).
3. Plug in washer or reconnect power.
4. Check the MCU by looking for operations of the drive
motor.
5. Check the drive motor for powered rotations.

FIRST COMMENT
F11 Serial communication error Communication between the Central Control Unit (CCU) and the Motor Control Unit (MCU) cannot be sent correctly.

Possible Causes / Procedure

1. Unplug washer or disconnect power.
2. Check wire harness connections to the MCU, the motor, and Central Control Unit (CCU).
3. Check the drive system for any worn or failed components.
4. Plug in washer or reconnect power.
5. Verify CCU operation by running a Diagnostic test or any cycle.
6. Check the MCU by looking for operations of the drive motor.
7. Check the drive motor for powered rotations.
8. Check that the serial harness at the MCU is not mounted upside down. The wires should be to the left when facing the MCU connectors.

Replace failed component.