The XM receiver is not "waking up".
Remove the back seat bottom cushion, I think on that one the fuse for the XM is in the right rear fuse block, pull the carpet on the floor forward the fuse box is there.
Look for a fuse that is labeled "s/band" and pull it for several seconds.
Turn the car back on after you put the fuse in and recheck it.
When the key is turned on the modules all get a "wake up" message. If the XM unit is logic locked it may not wake up. If it doesn't send out a state of health (SOH) message then the radio does not know it is there and it will not tune to XM as a choice. Once the XM module is awake the radio will begin working properly.
I know early production had issues with a bad part number that was prone to this. Do you have any factory warranty left? If so you might be able to get this covered if you have the old part number in your car.
If not you are SOL and this will be out of pocket. I can find the TSB number if you need it but the dealer will have to verify the part number.
PS. you can also just unhook the battery for a few seconds if you don't want to pull the seat out.