I just got my 2020 Prime home, and... selecting SAT radio gets me the "Check Antenna" error message. And yeah, a 2-day-old car is under warranty, but rather than sit around the dealer for ages waiting for them to fix something stupid and simple, I'd check it myself if I had any idea where to check. Any suggestions?
Don't know about 2020 for sure, but in my Gen 3, the XM antenna is one of the several antennas contained in the greeble that sticks up from the rear of the roof. It's hard to get any access to its connections or cabling without pulling on the interior headlining and trim and dash, and you'd probably feel awfully silly if you marred or creased any of that stuff in a two-day-old car, 'cause it's all pretty tedious to pull apart, and sometimes even being careful it doesn't go well. May as well let the dealer techs do that, at least until some of the new smell wears off.
My 2020 works fine. I would make an appointment to have the dealer check it out. I don't know of any way you can repair it.
OK; it's off to the dealer. I was hoping I could just stick my hand somewhere, like in the old days, and find the loose connection. The radio has worked every other day so far. (!) This feels like a multi-hour fix as they tear apart the headliner... :-(