Troubleshooting technique for checking the MCU in a Whirlpool Duet Sport washer
Whirlpool Duet Sport MCU Maytag kenmore washer
Yes, there is a 3 wire blue harness that runs from the CCU (Central Control Unit) to the MCU (Motor Control Unit) I believe it is the M3 connector. Unplug that connector at either end and let it hang. Now hit start, if the unit locks the door and acts like it is going to take off on it's little merry way, you have a bad motor control board. Chances are with this disconected after a minute or so a code will pop, but you will already have your answer. At the moment of start the CCU looks for two signals, door lock and motor control. If it does not see what it likes it tripple beeps. Removing the harness eliminates the bad signal. It will lock the door now and sit there looking for the MCU signal. No signal is better than a bad signal! Make sure you ohm your motor to verify it is not shorted and the source of the blown board though!
Here's the MCU test technique illustrated:
and Brother PDuff shares this old tech tip for checking the CCU:
Old tech trick for checking CCU's was to unplug unit and plug back in. If you hear a click from the CCU then the CCU was usually ok. But I think these new CCU's are onto that trick. Still researching that switch at access panel. I don't know if it would cause a problem but it has attracted my attention. Will advise.
Source: maytag front load washer (whirlpool) doesnt start just beeps