Just bought my 2018 on Friday, 34k miles, 8.4 screen, been loving it so far. Did remote start this morning, jumped in, no bluetooth, that's fine. Probably my phone I thought.
Switch over to radio screen, notice it has no volume. Can't adjust it (stuck at 16), can't change to FM or AM, can't change the XM station, except with the tune knob, which still produces no volume. Disconnected my phone, reconnected it, nothing. Tried the "soft reset" (holding tune and volume knob down for like a minute), nothing. Couldn't access the secret engineering menu. Saw this forum and tried the buttons on the back, but to no avail. I did notice that right when I get in, I can adjust the volume (still doesn't produce volume), but after about 5 seconds that sticks where it was. Gonna let the truck sit for a couple hours while I try to work and not think about the potential lemon I just bought, then go out and see if it's fixed itself. If not, will try negative bat terminal. Getting very worried.