[Carlucci]

Got an F6 code so I did some homework on here I checked out the motor with an Ohm meter and got 6ohms across the board and I also used my meter with an alarm on it to test the speed sensor by spinning it and getting a consistent beep from it so my conclusion was that it all pointed towards the MCU need to be replaced. It didn’t fix it!!!

I ran the spin/drain cycle and I spun the pulley on the back of the machine to assist it some and it started to spin. I am now thinking I have a low voltage problem. I also noticed the motor keep spinning beyond the required time it should have. I am thinking now that the low voltage could be causing the relay to not disengage. I looked at the 2 power wires that I think I found (2 pink wires on a plug at the top of the MCU) and got 117v on the top and the bottom was between 6-8v.

Please help me as I am stumped at this point not knowing where the voltage is coming from (CCU?) and where it should be?

[sidfink43]

120v (approx) comes from the CCU to the MCU which then converts the voltage to the level needed to drive the motor at the correct speeds as specified by the CCU and the user.

Your problems sounds like a classic MCU problem, but since you have already replaced it, and the motor checks out ok the like problems are the tachometer on the motor which requires replacing the motor, the wiring or the CCU itself.

How do you find out? Well a service tech would just start replacing parts until it worked. Why? Because these models are so complex, and the diagnostics so imprecise that replacing on spec is about the only way to fix them.

Rediculous. Yes.

[Carlucci]

One problem I have with that is the motor twitches like it wants to start and if I give it a simple helping of start spinning the pulley it spins up. Can I check the voltage or amps at the motor when its tiring to start?

[sidfink43]

You can check the volotage coming into the motor with the back off, but I do not have the specs on what the voltage should be.

Given that your motor starts up when you assist it, this points to a bad motor even though your resistance check on the windings seem to indicate it is ok. The other possibility is that the replacement MCU is bad, but that is unlikely. Of course, the motor going bad is also unlikely.

The CCU seems ok in that it is sending the right voltage to the MCU, and when it detects the motor is not turning it shuts things down.

I would try replacing the motor. If you buy from this site and the part does not fix the problem you can return it, see the returns policy for details and conditions.

[Carlucci]

It's easy enough to replace it and return it if that's not the problem. I will give it a shot and order one today.

Thanks,
Carl

[sidfink43]

Good, let us know how it turns out. Any info we can get on troubleshooting this troublesome model is a great beneft.

[Carlucci]

Ok new motor in and it's doing the exact same thing as the old one. Everything is being told what to do. It's just when the motor is told to spin it just twitches and if I just assist it the tiniest bit it spins on its own.

[sidfink43]

Well this is terribly irritating, probably much more to you than to us.

I think we are left with a wiring issue, in the wiring between the MCU and the motor, since it appears there is a voltage drop coming out of the MCU to the motor. Yes, highly unlikely, but it seems to be about the only thing left.

[Carlucci]

If I knew the voltage going into the MCU it would be nice. I got 117V on the top wire going into the MCU. I would like to know the voltage of the 2nd pink wire. That one seems low to me.

Do you have any ideas on it possible being a bad ground to the MCU or Drive motor?

[sidfink43]

You should have 120 v on a pink to pink connection.

I am going to link you to a service manual, but if you do not have 120v coming into the MCU then the CCU is likely the problem. If so, the wiring is still the most likely.

https://secured.whirlpool.com/Servic...0Job%20Aid.pdf

Hope this helps