F-01 Error Kenmore H2Et / Whirlpool Duet Sport Washer won't start

[John D]

My Kenmore H2Et washer has a F-01 error code and won't start. The error happened while the washer was in its spin-cycle and attempting to drain. The door remained locked and we tried to get it to resume or run its diagnostic but would not start up again (note, I'm not sure we followed the steps to run the diagnostic test correctly before I started pulling things apart). Note, this model is similar to the Whirlpool Duet Sport.

1- I pulled out the power cord, unlocked the door manually  and opened the bottom access panel to access the drain cap. I removed a lot of debris, it was quite dirty. I screwed the cap back on,  plugged the power cord  back into the outlet and tried to start it. Again I got F-01, door does not lock, no water through the inlet values, no motor start. 

2- I read from the manual that the CCU needed to be replace. I researched the Internet and read somewhere that if we hear the relay when the unit is plugged in, the issue is mostly likely the MCU. Several folks claimed it fixed their issue, so I went ahead and ordered a used MCU. After anxiously waiting 5 days, I get the MCU. I plug it in and get the same symptom. F-01 error code, door does not lock, etc...

3- Feeling really stupid for ordering the MCU, I search for wiring diagrams for the CCU trying to narrow down the issue. I found a wiring diagram in document part No. 8540259 (on page 13), which I would attach here but have not figured out how, and used my multi-meter to take some readings.  The relay at K1 appears to be closed. If I measure the voltage at the exit of K1 leading to the relay DR1 going into the Locking mechanism (DS3 pin 1) and the IF2 (pin 1) source interface, I get a reading of 120V. However, I don't read 120V at the MS2 (pin 1 and pin 2) that goes toward the MCU. I'm assuming this is because the K2 relay is still open, which I verified that it is open. 

So one question is, why is K2 still open. What event needs to occur for it to close? I tried to measure VDC voltage across the coils for both K1 and K2 and I don't get a reading. Instead, I get a very low 20-40 mV AC across the gates. Is that expected/normal? 

Also, I don't measure 120V at DLS3 between pin 1 and pin2, or between DLS3 pin 2 and pin 3. Any ideas why, or what else I can/should be doing to narrow this down further?  Note, I have verified that DS2 circuit is working correctly. The washer does detect when the door is open and does not go further when it generates F-01 unless the door is closed.

Appreciate any input. I thinking of replacing the K1 and K2 relays. It's a bit of a shot in the dark at this point. 

I'll probably end-up buying a new washer by the weekend at the rate this is going. A shame to fill the landfill with this big heap of metal just for a few $2.00 components that are failing but unfortunately this is the world we live in. :-(

[John D]

Wanted to make a correction. I said earlier that the relay K1 is closed. It's actually open, I got mixed up with the pinouts and by the fact that we get 120V if you take a reading between IFS pin 1 and the "out" pins on the K1 relay, or vice versa. To further complicate things, if we run a continuity test between the "input" and "output" of the gate we get continuity (i.e. low resistance / beeping) indicating the gate is closed. However, there is a 120V drop between the two. So, something's not right with this part.

Also, the AC voltage at the coil terminals is 2 mV for K1 and ~40mV at the coil terminals for K2 with the power on. It drops to about 1/2 of that with the cord plugged in and power off. BTW, I did try to short the gate at K1 but that does not seem to help (i.e. still get F-01).

[Budget Appliance Repair]

Doesn't matter what everyone says on the internet!!!!

F01 is Main CCU error and would usually mean the CCU is bad if it comes up pretty much immediately, not the MCU that you replaced.

The MCU is the most common failure of the electronic parts, hopefully you purchased it from the parts site linked to this website, (Appliance Parts Pros) or RepairClinic where you can return the new MCU that you purchased and just be out the shipping charges.

As far as board level repair, (we don't really get into that here), but most likely not a problem with the actual relays but more likely logic circuits not turning relays on, (there is no way you will find a schematic of the actual CCU board, so you are on your own as far as figuring that out).  The schematic of the CCU that you are working with is of course not a full detailed schematic, just the basic 110VAC and triac circuits to the loads thru the board.

Did you check the solder connections on the back side of the board for the relays?  I've never seen one of these CCU boards burn the solder connections to the relays but it would be possible.

Edited May 27, 2017 by Budget Appliance Repair

[John D]

"Doesn't matter what everyone says on the internet!!!!". Note, we're using the Internet here as well. It was really my fault for not checking further before reaching a conclusion. 

I got the part on ebay and the seller says he will take returns. I haven't tried returning it yet. Paying $200-$300 on RepairClinic or AppliancePartsPros for a board on an old washer doesn't make much sense IMO when you consider:

1) Something else can be causing the failure on the board, and it may damage the new board  again soon after I install it.
2) The washer is old and other parts are more likely to start failing
3) My wife doesn't really like this washer
4) A brand new washer, that my wife wants, is about $500  

The solders behind the relays look okay. I'm not seeing any blown or missing solders joints. The only thing I've noticed is some browning (a millimeter maybe) going down the trace/circuit out of K1 relay. I do find it odd that the multimeter thinks there's continuity across the K1 relay gate, yet I measure 120 voltage drop across it. 

Having said that, I agree it's highly likely there some other logic circuit failing on the board but I'm curious with what's going on with this relay. I going to try removing it over the weekend and maybe open it up. It's turning into being more of a side project at this point.

[John D]

I replaced K1 relay and the F-01 error code is gone. Yay!  Now door locks and I hear a few clicks when I press start.

Unfortunately, I now run into another error -- F-28. I pulled the MCI connector on the MCU and measured 5V across pin 1 and pin 3. I get 3.5V between pin 2 and pin 3. Pin 2 is the data pin from what I recall so probably bouncing between 0V and 5V. I figure 3.5V is probably what the multi meter would end-up reading in such a case. Short of having access oscilloscope not much more I can verify on this connector.  Seems okay.

More sleuthing for me. Any ideas/suggestions?

[John D]

Nevermind, I found this..

 

[chris_goulet]

There are four possible causes for F-01 that I know of:

CCU should make 2 clicks within 0.2 seconds when machine is plugged in. If hear none or only 1 click, replace CCU or replace relays K1 and K2 on CCU board (buy at Mouser or Digikey).

CCU does 2 clicks, but drum never rotates: replace MCU or re-solder GR1 bridge rectifier (4 pin device screwed to heat sink) on MCU board if no diodes or tracings look burnt.

CCU does 2 clicks, and drum rotates, and door locks, then later gets F-01: remove debris if drain pump is jammed or replace drain pump if it has a bad bearing or bad coil (should be ~12 ohms) AND / OR replace CCU or re-solder drain pump triac TR4 (loose pins) on CCU board.