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Smashycomman

Maytag Maxima MHW7000XW0 won't go through diagnostics

20 posts in this topic

Hello everyone! 1st post. Been using the site for a while, but most of my questions were answered from just reading.

 

I work for an appliance retailer that my parents own. We've never had a service department before, but I've been learning for about 3 years to be a service guy/ fix up used.

 

I'm attempting to fix this washer for a customer. It's only about 2 years old, she got it from us, but she didn't want any extended warranty, so she's paying for it out of pocket. ( I think we're doing the service for free, though)

Apparently, the error code "F1E2" came up for her and the washer wouldn't unlock for about 20 minutes. She had a guy come take a look at it, and he diagnosed it as the MCU and possibly the CCU.

 

We ordered the MCU and I put it in, but of course it didn't work. I put it into diagnostic mode, and it goes through "C00" and to "C01", but then goes back to "C00" and does nothing other than activate the pump once in a while. It then doesn't advance past "C00".

 

I did my best to double-check the connections and as far as I can tell, I think the CCU may be bad. I just wanted to get all of your guys' advice before ordering it.

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Need appliance parts? Call 877-803-7957 now!

Thank you very much!

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Ok, so I watched the videos, and they were very informative, and I learned a lot, but I haven't come to a conclusion. I tested for 5V at the MI3 connector, and it's putting that  out, so supposedly the CCU could be good, right?

I tested the motor windings and they're all 9.8 Ohms. I tested the DCS3 pins and they have continuity when they're supposed to, so the door locking mechanism should be fine. I had even replaced the MCU like I said, so I doubt that's it, unless the new one is bad, but like your said in your video, I shouldn't assume it's the MCU anyway.

 

I, in my great lack of experience, want to say the CCU is still bad, even though it's sending the 5V to the MCU. I mostly thinkg this because it won't get through the "Quick Diagnostics", so maybe it has the ability to communicate with the MCU, but something internal in that is preventing it from working properly. It's easy to blame boards, though.

 

What do you, Samurai, or anyone else think? :thanks:

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Are you getting 120Vac to the MCU? Assuming that you are...

I think the fact that the CCU is not doing the full diagnostic routine shows that the DC logic portion of the board is borked. I see a CCU in your future. Part number: W10406636

Part number: W10406636

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Yeah, I'm getting 120 to the MCU. I'll order that and let you know if it fixed it. :)

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Alright, so I ordered the new CCU, put it in, tried it out again, but it's still doing the exact same thing. Motor isn't turning at all. I try to start a cycle, and it acts like it's going (timer comes up- door locks, ect.) However, it doesn't begin to fill and doesn't turn or anything. Then, after about 5 minutes, the F1E2 error comes up.

 

When I put it into diagnostics, it still just goes from C00 to C01 and back to C00, even with the new CCU. I'm at a loss at what it could be

 

C01 is testing the heater, steam heater, and temperature sensor. Could it be something to do with one of those?

 

I'm going to start over and test everything again.

 

Any advice on what else I should do?

 

Thank you.

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Have you ohmed out the motor winding resistance?  What did you get?

 

Are you also getting the DC voltage to the MCU from the CCU?  

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Let me tell you exactly what I did, since you can tell me if I did anything wrong in checking these things.  :turned:     (I'm still a newbie in the appliance repair business. I even had to attend the basic electricity class put on by Fred's back at ASTI earlier this year, so obviously I need all the help I can get)

 

I unplugged the washer. I unplugged the cable attatched to the MCU. The one that says "To motor" in the diagram in the tech manual. I put my needle leads in the 1st and 2nd, then the 2nd and 3rd, and finally the 1st and 3rd. They all read 9.2 Ohms. (I'm using a different, better multimeter than before when I got 9.8 Ohms) My multimeter is set to the 200 on the ohms part. The tech manual says they need to be between 8.5-14.0 Ohms, so that seems like it should be good to me. Again, I just want to cover everything I did, in case I messed up.

 

I plugged the washer back in, then unplugged the MI3 connector from the MCU, (the one that says "MCU communications" on the tech manual), and put my needle leads on pins 1 &3. I got about 5.19VDC.

 

I also checked the AC voltage from the MS2 connector, but got nothing, since the washer is in standby mode. (I assume this is normal. If this isn't, then I'll say that when I got the 120VAC, it was only when the motor was making sort of growly noises during the diagnostic test. This is when it gets to the C01 part of the test- it'll activate the steam valve, then the motor growls a bit, but the tub doesn't turn. That's the only time I can get 120VAC to the MCU, I hope that's the only time it's supposed to get power, other than the 5VDC through the MI3)

 

The tub does turn freely, as well, so I don't think it's something preventing that.

 

Again, thank you very much for taking the time to help me.

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 I put my needle leads in the 1st and 2nd, then the 2nd and 3rd, and finally the 1st and 3rd. They all read 9.2 Ohms.

.

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I plugged the washer back in, then unplugged the MI3 connector from the MCU, (the one that says "MCU communications" on the tech manual), and put my needle leads on pins 1 &3. I got about 5.19VDC.

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I also checked the AC voltage from the MS2 connector,...then I'll say that when I got the 120VAC, it was only when the motor was making sort of growly noises during the diagnostic test. This is when it gets to the C01 part of the test- it'll activate the steam valve, then the motor growls a bit, but the tub doesn't turn. That's the only time I can get 120VAC to the MCU, I hope that's the only time it's supposed to get power, other than the 5VDC through the MI3)

 

The tub does turn freely, as well, so I don't think it's something preventing that.

 

 

 

Excellent diagnostic report!  Based on the fact that you're getting BOTH the 120V AC power supply and the DC control signal from the CCU and that the motor windings test good, the problem has to be the MCU Part number: AP5176711

Part number: AP5176711

 

You can return the CCU for a refund if you purchased it through the part link I provided above.  

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I already replaced the MCU first thing. What are the chances I need to replace it again? The one I put in there is new.

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Oh, also, a service friend I had suggested replacing the water pressure switch since many of the whirlpool-built frontload washers have an issue with it. Do you think that could be it? How would I test that?

 

Thank you

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So, let's recap:

 

You have replaced BOTH the CCU and MCU with NEW OEM replacement parts and the problem persists.  Is this correct?

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Exactly. Ordered them from our regular parts house since it's cheaper for us. They came in a FSP box, strait from Whirlpool. The problem is still there. :/

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I just checked the water inlet valve coil resistance, and it's supposed to be around 990 Ohms. They're all different, but they're all about 1050 to 1070 Ohms. Looks like the inlet valve may be bad. I'm going to see about replacing that.

 

Does that sound like a good idea?

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thats not that far off, water valve is most likely fine.  the symptoms sound just like a bad mcu, it is possible you got a defective one

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Hmmm...ok. I checked the DCV coming out of the MCU, going to the motor, and my digital multimeter could only read the voltage for half a second, and only when there's that click, then the growling  (actually, it's more like humming. I think it's the motor trying to run.)

 

I only get the voltage for a second, but what I get it only about 9.18DCV. I don't know if my meter isn't quick enough to read it, or if it really is only 9V. Also, I'm not even sure what the voltage to the motor from the MCU is supposed to be, but from what I can tell, it seems like it's supposed to be 12V.

 

The 120VAC coming from the CCU to the MCU will happen during that same humming, but it happens for a good 4 seconds or so... more than enough time to get a good reading. The DCV coming out of the MCU only happens for half a second like I said, so maybe you guys are correct. Maybe the MCU I got IS bad. Great. :rolleyes:

 

Does that sound like a good diagnosis?

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Hmmm...ok. I checked the DCV coming out of the MCU, going to the motor,

 

 

You can't measure the MCU output voltage directly.  You can measure the AC and DC INPUT voltages to the MCU.  And you can also measure the stator winding resistances.    If all those check good, then the MCU is borked.  Maybe a bad one out of the box.  Maybe got fried when you were installing it.  

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Samurai, I never should have doubted you! I went and got another MCU. Put it in and it's humming along nicely right now. The MCU I got from my supplier WAS bad!

 

Thank you so much for all of your help. I'll be coming back here for all my questions from now on.Thank you! :thanks:

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Thanks for letting us know!  Glad you got it fixed.   :rocker:

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