Maytag washer MVWC425BW0 - sits through cycles

[GunnerCO]

Okay, geniuses, be warned this stumped the crowd at another forum... and me, which maybe isn't saying a whole lot.

Maytag washer, MVWC425BW0. Have technical manual. Have a pretty fair amount of repair experience and 100% success rate.

The washer goes through the wash cycle normally, and then basically doesn't move the drum ever again. Here's the sequence:

1. Wash cycle goes normally, drains.
2. RINSE LED lights. Rinse fill occurs normally.
3. Right about this point, the LID LED lights starts flashing. The lid is locked.
4. Nothing happens for about 10+ minutes. (Total silence, not one indication the motor is being engaged for any reason.)
5. Drain.
6. Drain drain drain drain drain until the pump is growling.
7. Change to SPIN LED.
8. More drain-drain-drain. LID LED goes out right around here.
9. Nothing happens for about 15 minutes. (Silence.)
10. DONE.

Tub is empty, clothes are sopping and un-spun.

3 times out of 4, changing to DRAIN AND SPIN will successfully spin the load dry. Every once in a while, particularly if I interrupted the above broken cycle, DRAIN AND SPIN will begin agitating. A 10-minute unplug is all that resets things.

Okay, you're all yelling "CONTROLLER!" at me. Well, three controllers did the same thing. Original (now back in place); used-tested-good; certified refurbished. All three did/do exactly the same thing and show no other evident faults. (And yes, I ran a calibration on each new install.)

Faults, you say. Well, let's start with a manual test of every system. Cold fill, check. Hot fill, check. Drain, check. Low agitate, check. High agitate, check. Spin, check. Not a fault or an unusual noise or any sign of problems for a minute or two on each motor function.

Codes! you yell. Vary a little but mostly "RPM fault" and "Motor speed fault." Nothing else. No lid-lock errors.

Flipped it over, checked the start capacitor (seems good from quick tests) and drive belt (just fine).

So what what we have here is a great basic washer that can't be proven to have any faults whatsoever, but silently goes on strike for the rinse and spin cycles.

 

Why?

[GunnerCO]

No edits? Anyway, around 5-6 the lid unlocks and remains that way, too.

[Budget Appliance Repair]

I would try changing the shift actuator - all codes point to that, (it contains the speed sensor and shifts between agitate/spin).

They can be intermittent and do the things you describe that it is doing.

[GunnerCO]

5 hours ago, Budget Appliance Repair said:

I would try changing the shift actuator - all codes point to that, (it contains the speed sensor and shifts between agitate/spin).

They can be intermittent and do the things you describe that it is doing.

One thing I've tried to avoid here is simply replacing everything until it works.

If all five drum modes work perfectly, in any order, for pretty much any duration, using the test modes, wouldn't a shift actuator fault show up at some point? (I can hear the little humming as it changes modes between agitate and spin, each time I change modes.)

[GunnerCO]

...sorry, "three drum modes" - spin, low agitate, high agitate. I was thinking of drain and fill too.

[GunnerCO]

...and (darn, isn't there any edit function, even for a few minutes?) there's nothing variable or intermittent. It does *precisely* the same faulty sequence every time. The tach test works; the RPM/motor faults are the only sign of any problem, other than that it just sits quietly through the rinse and spin cycles.

I am getting along by running two wash cycles, the second without soap, and then a manual spin. But it's a PITA.

[GunnerCO]

Okay, you may be right. I ran more tests and I'm definitely getting the "hum"/speed fault error on spin. The trick is that it seems to be dependent on load; my empty tests worked fine, but now with a half load (of soggy dog blankets, sigh) it faults. Replacing the actuator assembly.

Can you make a guess as to why this would cause the RINSE cycle to fault, though? If WASH works fine, and the speed sensing isn't used until SPIN (as I read the tech manual), why would RINSE just sit there and do nothing with the drum?

[DADoESTX]

The Rinse period includes a spin after the wash water drains to extract the detergent/soapy water from the clothes (usually some water sprays during the spin), then refill and agitation.

Have you accessed Diagnostic Mode to check for fault codes?

Edited May 16, 2021 by DADoESTX

[GunnerCO]

Right, I wasn't thinking about the spin in between WASH and RINSE.

Yes, have pulled codes and reset them many times. Always RPM or motor speed faults.

I ordered an actuator/speed sensor assembly.

It also seems to have something to do with warm and cold conditions. Any time I run tests etc. after a failed cycle, even fewer things work right. If I let the unit sit for an hour or two, I can get a slow and fast spin out of it before it faults again. Since the motor, gearbox and splutch all seem to be doing their jobs, I guess this does all point back to speed sensing.

Will update after I get the  part.

[GunnerCO]

So I replaced the actuator/sensor, and it wouldn't pass any of the motor tests - just a little "boomp" of the drum about once a minute. Ran the tach test, it failed (one LED remains lit).

So, bad sensor on the new unit?

I just wanna get some clothes washed! 🤪

[DADoESTX]

Run calibration?

[Vance R]

Pull the wash plate and check the basket hub, transmission splines for wear.

[GunnerCO]

Nope and nope. Faulty speed sensor - not completely bad, in the original, which would pass the tach test and allow about one spin cycle before heat or vibration made it flake out.

The replacement was faulty.

Replacement #2 is happily running a load right now. Kudos to Budget Appliance Repair; he called it.

[ABA Tech]

On 5/25/2021 at 8:03 PM, GunnerCO said:

Nope and nope. Faulty speed sensor - not completely bad, in the original, which would pass the tach test and allow about one spin cycle before heat or vibration made it flake out.

The replacement was faulty.

Replacement #2 is happily running a load right now. Kudos to Budget Appliance Repair; he called it.

Glad it worked with the second part. Make sure you run calibration after replacing the actuator.

[kokomo]

1st part pbly still good, remember to calibrate nx time. Sure made that hard on yourself.