My front load washer has burned up the MCU. Do I need to replace the motor and the MCU at the same time? Does the motor burn up the Mcu?

I went through this some time ago with my whirlpool duet washer. I had the service man come out after I replaced the mcu and still did not work. He told me that he had no way to check for sure that it was the ccu but said he thinks that I should replace it so I did and it solved the problem.. I still don't understand why he could not tell me for sure that the ccu was the problem because it cost a lot to order it.

Anything with an IC can quit working. Also a motor that quits working can still have continuity if it isn't tested right giving false readings. I wonder if you can prove that the motor works by giving it power through test leads and if it needs temporary power to a start winding do so. If it has a centrifugal switch i would suspect it. Open the centrifugal switch and clean the contacts and verify that it opens and closes.

F11 Serial communication error 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.

Read more: http://www.appliancepartspros.com/repair-help/whirlpool-fault-codes.html#Whirlpool Duet Front Loading Automatic Washer Fault Codes#ixzz2P3BOEFKI
http://www.appliancepartspros.com
you'll need to call someone in on this one,boards are very expensive and like it says it names both the ccu and mcu boards or the motor,if you call say whirlpool they might give you the part but you pay for labor and they will have the boards on the truck,the guy will replace one board at a time to see what one is bad,not like the older machines that you can check the parts with a meter.good luck

Hello

Error F31 in your whirlpool duet washer is displayed due to MCU (Motor Control Unit) failure. It is displayed if the heat sink gets too hot and then the MCU stops motor, then MCU sends the signal to CCU (Central control unit). Please check the wire connections between the CCU and MCU, if thats fine then check the motor operation. Hope you understand...replacing the part# that has gone bad is recommended repair. Please get back to me if you have any other questions.

Kevin

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.

No do the following:

• Check wire harness connections between the Drive Motor and the Motor Control Unit (MCU), and between the MCU and the Central Control Unit (CCU)
• Check the MCU
• Check the Drive Motor
• Check the Wire Harness

If the wiring is definitely OK and the drive motor is OK then the MCU is most likely to be the culprit.

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

The error is an indication a motor speed problem. You will need to check the following:

- Check the wiring harness. Verify all connections between the Drive Motor, Motor Control Unit (MCU), and Central Control Unit (CCU).

NOTE: The MCU is a circuit board located in the vicinity of the Drive Motor on the bottom rear of the washer. To access the MCU, you will need to remove the back panel of the washer.

NOTE: The CCU is the main computer for the washer and is located behind the wash tub. You will need to remove the top panel to access the CCU. This is accomplished by removing the three screws in the back of the washer that hold the top in place. Once the screws are removed, the top panel will slide back, then lift off.

- Check the Drive Motor. Perform a continuity check of the Drive Motor windings. Remove the connector plug and check across pins 1 to 2, 2 to 3, and 1 to 3. All readings should be approximately 6 ohms. HINT: You can also take this reading by removing connector 2 from the MCU and measuring across pins 1, 2 and 3. If the readings are good, this will also prove the wiring and connector good.

- Check the MCU. The connectors are numbered 1 to 3 (L to R). That is, with the MCU installed, connector 1 is on the bottom, followed by 2 in the middle, and 3 on top.

Connector 1 - is the serial communications link between the MCU and CCU and has three wires. At the opposite end, this will be the 2nd connector from the rear on the left-hand side of the CCU.
Connector 2 - is the link between the MCU and the Drive Motor. Pins 1, 2, and 3 on this connector are the Drive Motor windings. Pins 4 and 5 are for the tachometer.
Connector 3 – is the primary power connector. Pins 1 to 2 should read 120VAC with the door in the locked position. Pin 3 is ground. At the opposite end, this is the 4th connector from the right on the front of the CCU.

NOTE: All the connector pins are numbered R to L.

If your continuity readings are normal for the Drive Motor and you have verified all connectors, replace the MCU.

If any of the Drive Motor windings indicate readings higher that 6 ohms, replace the Drive Motor.

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F11 = 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


Most likely is a problem on the controller board due to vibration. If you are habdy, and wish to try repairing the board instead of replacing it, take the top cover off, then pull the white relays ( there are 2 Omron ones K1 and K4).
You have to remove the solder and then pull them off. I can almost guarantee one is burned. Clean off with a pencil eraser or scrape with an Exacto knife... then switch them as one of them carries a lot less voltage, therefore doesn't burn.
You need a fine tip soldering gun for re-soldering or you may burn the circuit board. This may get through a year or two more before you have to replace these relays.
If you are handy, you can do it yourself. The repairmen will only want to replace the whole CCU board and that is expensive.

Good Luck!!

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F11-Serial communication error
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.(you can find the location of CCU and MCU through the manual)

All the best,
sunny