Heated steering wheel not working

[JP Cortez]

Hi all I have a new to me 2018 sierra denali 1500. When I purchased it the heated steering wheel was not working and when pressed the button would illuminate for 3-4 seconds and shut off. Service noted it and I told them I would bring back in a couple weeks. In those couple weeks it mysteriously worked for a multiple days so when it went it to service it was working and they could not duplicate problem. I brought home and sure enough coldest week of year (-16f) its not working again. Is there a module or is it the wheel itself I'm looking at replacing? I have til April for warranty is this something I can take back in and have looked at under warranty?