Hi
I have a 2013 Yukon XL with the retractable boards.
Luckily, when I bought it used I also bought a Service Contract from Endurance.
BTW> Endurance is AWESOME !!!
Back to the boards.
I live in MN and this year we had a stretch of below Zero ° for weeks. Double digits below Zero.
This is my 4th winter having it, and they have never failed until this winter.
When stopped working, driver side was stuck down, and passenger side was stuck in up position.
Dug into it thinking like you might be something I could just do.
Was thinking there must be some reset procedure, consulted forums, but ones suggested didn't work including the battery neg cable disconnect.
Since I had the warranty, took it in hoping for coverage, but some components are, & some aren't.
Only few things it could be & as this suggestion you rec'd for the control module, that was my issue as well after diagnosis.
Found out that the module is covered and the parts on order.
Next winter I'm putting them down & then switching off, as I'm convinced the super cold weather took my module out.
My thought & situation
Best regards
Lfryklu