service manual

[RAH52]

Looking for a service manual for a Maytag MHWE300V front load washer . Fairly new product ,can't locate the manual . Thanks

[Repair-man]

New to you, maybe...goes by the name Epic Z in our circles...here the Manual:

http://appliancejunk.com/forums/index.php?action=downloads;sa=view;id=86

Care to share what problem you are having so we can all get our jollies?

[RAH52]

Fault code F28 communication error . Checked all connectors @ ccu and mcu  . Washer locks gives a squirt of water unlocks ..locks again and sits there ,motor does nothing ,after 30 seconds F28 . I suspect mcu issue but don't have one to try ..need to order it . This is a full size machine but the ccu is where it is on a duet sport or epic Z ,not at the back like a full size duet . Why do they change parts in these faster than I change my socks . Seems like every run the parts have changed so carrying stock can get expensive .

[Repair-man]

 The motor control is not working as it should and the CCU is not recognizing any motor RPMs. I usually inspect the wires from the motor control to the motor, as they are fragile and a common point where broken wire connections occur, especially the lower two wires going from the Hall sensor on the motor back to the  board. If all the wires and connections look secure, it is most likely a bad motor control board.

You say you "checked" the MCU...just how did you go about that?

[RAH52]

I said I checked all mcu connections and connectors for wires backing out . I did continuity checks and found no abnormalities .

[Repair-man]

OK, lets go with what WP says about the F-28 code:

The 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).
– Check connections of the CCU board within the housing.
– Make sure all grounding switches are engaged.
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.


If you place it directly into a spin-only cycle and it does not run , I would be prone to replace the MCU first. You "found no abnormalities", but that means you don't understand how the CCU and the MCU communicate. As I said, the CCU is looking for motor rotation. It apparently sees none. This means a bad MCU or in rarer cases, the motor. It is easy to OHM the motor, but not easy to check the MCU so you have to go on past experience, and I have a little of that.

[RAH52]

By saying I found no abnormalities I mean't that all the wires in the harness had continuity .

[Repair-man]

If the MCU is getting 120 volts from the CCU when the unit is in the spin cycle, the MCU is bad. Voltage is provided  thru the black and white leads going into the MCU.