How to fix all serial communication error codes in Whirlpool built front load washers

by Samurai Appliance Repair Man, www.Appliantology.org

Whirlpool Duet SportThe dreaded “serial communications error” in Whirlpool-built front-load washers appears as various codes, depending on the particular model. On the Old-Skool Duet washers, the most common communications error code was F-11: communications error between the Central Control Unit (CCU) and Motor Control Unit (MCU). On the new model Duet washers, this same error has been re-labelled as F-28. On some Maytag front loaders (all built by Whirlpool, in case you didn’t already know that), you may see an F6E2 fault code, which is a communications error between the CCU and the User Interface (UI) boards.

Many a fine battle-hardened appliance warrior has been befuddled by these error codes and have needlessly soiled their undergarments throwing every control board in the box at it.

But these serial communications error codes all have one big thing in common:

They are almost NEVER caused by a bad circuit board! Instead, they are exactly as the error code description says: a COMMUNICATIONS error between two boards. In other words, a bad connection.

Oh, I know— you’ll hear some guys swear it was a bad board because they replaced the such-and-such board and it fixed the problem, so it had to be a bad board. But I’m here to show you that in 99.9999% of these cases, the board itself is perfectly functional but the real problem is the CONNECTIONS to the board.

“Uhh, howzzat, Samurai Smart-ass Guy?”

Ahh, Grasshoppah, make still your mind and the Samurai shall reveal the truth unto thee. And the truth shall make you free. Come with me now on a journey of Total Appliance Enlightenment™…

Let’s think about the modern front loading washer and the average laundry room for a minute. In these front loaders, you have at least two (CCU and MCU) sometimes four (CCU, MCU, UI, and Steam Board) different boards that all need to talk to each other and pass data back and forth: digital data, voltages. How do they do this?

Since they haven’t incorporated internal Wi-Fi into appliances yet, all these boards are connected to each other by special wire harnesses called serial communications cables. All this data exchange is fact-checked and verified by a process called “handshaking” (yes, that’s what it’s really called). If, at any time during this continuous process of passing data back and forth an error is discovered during the handshaking, the CCU throws a serial communications error. The closest it can get in the error code is by telling you which two boards had trouble talking. But that’s close enough!

So what causes these handshaking errors? Lots of things! In fact, given the conditions that these washing machines have to work in— lots of vibration, moisture, humidity, heat, etc.— it’s amazing they work as well as they do. But all it takes is a loose connection at a molex connector on a wire harness or an oxidized pad on the control board to disrupt that handshaking. It doesn’t even need to be a totally broken connection, just one with low enough signal-to-noise ratio that the CCU can’t tell which is signal and which is noise.

Okay, here’s the part you’ve been waiting for: the Silver Bullet Fix for these elusive and mysterious serial communications errors in Whirlpool-built front-load washers.

The harness itself can (and usually does) check good. That’s not usually the problem. The problem is at the harness connection points where the molex connector on the harness connects to the boards at either end. The

tines can become loose or the pads on the board may become oxidized. Here’s a technique that I’ve used with great success in these types of problems. BTW, all modern front loaders work the same way and use pretty much the same basic technology so this solution concept for serial communications errors applies to all brands of front load washers, not just Whirlpool:

14 Comments Add yours

  1. rickstv and appliance viborg SD 57070 says:

    thanks great help.

  2. Jeff says:

    Thank you for this common sense post. Everything I have read on the internet was telling me to order MCU and CCU which did not make sense to me since the interface and diagnostic test was working fine.

    I will try this suggestion and let you know what results

  3. virginia says:

    please tell me what is the cost to replace and i.stall this ccu in my whirlpool duet washer 2005 model gwh9150pw? louisville ky

  4. Jeff says:

    What if the machine will not run the diagnostics? whats the next step then?

  5. Chip says:

    I get the diagnostic display started but it goes to f1 1 immediately.
    I cleaned the terminals but still get f11. Your video is good but there are gaps of information needed for guys like me. What does it mean if it doesn’t run the diagnostic. Does it mean a bad board, and which one. I am very disappointed with whirlpool and will stay clear of there product I have already thrown the dryer away and about to toss the washer

  6. Brian Leach says:

    HI, I have A Whirlpool Duet Washer, get F 28 error, go to diagnostics, stops at C02 (attempts 3 times) I checked the dispenser Switch and motor, Had about 1400 ohm pins 3 & 1, infinity 6 & 5. Ordered new disp. motor. New unit has same readings, also diagnostics stops at C:02 again. (Also FYI have switched Hot and cold controls and they work fine) Help me please? Thank you.

    1. Ro Werthe says:

      I’ve the same deal going on as Mr Leach 1/21/15 only after lock it fills for two seconds then stares at you. It will not function in manual diagnostics will not auto drain.Dispensor motor will not move. It locks /unlocks door fine. In this case nothing is talking and appears functional components have gone on strike. New harness? Which one? Any comments ?

  7. Rachel says:

    thanks I thought the explanation and the video helped a lot compared to previous tips that didn’t last long.

  8. Stuart Putz says:

    Spot on! Had been told was motor control board. $200 in parts & $130 in labor. Tried your repair, works great! Thanks for the logical explanation & valuable insight. Was ready to buy new washer, this one still looks new & has years of service left in it! Thank you!

  9. Nate says:

    Nearly all front load washers and other appliances nowadays are designed and built to be utter garbage. You state “given the conditions that these washing machines have to work in— lots of vibration, moisture, humidity, heat, etc.— it’s amazing they work as well as they do” but think about all the other devices with electronics that are subjected to just as bad, if not worse conditions. My prime example is an automobile, engine compartment temperatures, and even passenger cabin temperatures can greatly exceed the range of what a typical white good will see, from hot sunny days, to well below zero temperatures. They also tend to experience much greater vibration from road conditions and are subject to salt, road grime, and all sorts of weather conditions, but do not experience near the errors and failures of a typical front load washer. I am not saying automobiles, motorcycles, lawnmowers, ATVs, etc are without their problems and faults, but if a company truly wanted to build a front load washer that could make it more than 16 months before encountering an error, they could definitely learn a thing or two from the electrical engineers designing products for real world harsh environments. Heck, even your typical PC has a higher case temperature than the 120-140 degrees of an average household’s hot water system…

  10. jane says:

    Wow! time for champagne! I fixed my Duet thanks to you. I live in an ultra-rural community; takes an act of congress to get something fixed. But you did it! YOU ROCK!

  11. Timothy says:

    My Whirlpool Duet Steam Tumblefresh 4.4… Unit is approx 5 years old… The machine looks like it will start but nothing happens.. all the lights that should be on, are on… nothing happens. Upon cancelling cycle, the door will not unlock, and unit will not POWER OFF. I unplug and then I can unlock door. I ran TEST MODE… everything works EXCEPT c05 and c08 … DRUM not spinning? Is this possibly a belt in the back? or MCU/Motor issue?

  12. Timothy says:

    How do I get from Test mode (C01 – C08) How do I get to the F-mode?

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