Sirius XM?

As Donn says, you need to get the additional receiver. The radio ID is part of it, NOT your installed radio. You can tell if you already have it by switching your radio to satellite mode. If it has the receiver already hooked up, all you will get is channel 1 and the radio screen will display the ID number. If you do not have the receiver, What happens is determined by your radio manufacturer. It may not even go into sat mode. The receivers come with a small stick on antenna with a long wire that can be a challenge to snake from the roof to the receiver (which generally hides in the ball of wires that lives behind your radio). Most RVs I've seen that came with a satellite ready radio also had the receiver as the manufacturers knew how tough it would be to get the antenna wiring in. You might want to check on your roof for a small (about 1 1/2" square) black lump that is the antenna. The extra $60 or so for the receiver let them advertise "satellite radio" equipped. To me, RVs are the best place for sat radios as they usually spend a lot of time covering long distances and get parked in remote locations, both activities especially suited for sat. Just nice being able to drive coast to coast listening to the channel you like.