F28 fault code

[RAH52]

Whirlpool WFW83000 Washer - This F28 fault code is the dreaded communication error .According to the tech sheet, could be a wiring issue between ccu and mcu, or could be ccu,or mcu . I have a terrible time diagnosing this issue .Parts are too expensive to "try" . In Canada you order it and you can't send it back especially electrical . Tech line isn't much help . Do any techs out there have a logical action plan to repair this fault.

[krazytech]

Has any one changed the MCU ... the blue wire on top can be plugged in upside down the wires should wire face the left.

check all wires for cuts or bad connection...

I would "try" the MCU first...