I have a 2013 GT 378TS and last winter my steps would not function in cold weather. Eventually they may extend and if they did sometimes it would take several minutes for them to retrack. The magnet was not the issue. Not sure what it was, but most likely the control unit did not like cold weather. Since they always had a very loud clunk in them from day one, I got the factory to replace the Lippert steps with kwikey steps.
Mickey & Sue Stamper
2013 GT XL 378TS
2013 Ford Escape on Landgrebe tow dolly