Text scrolling in XM radio

[rcan1015]

I have a 2012 base HL with the Type B stereo (single CD with radio and CD changer controller). At least that is how the owner's manual describes it. What is the CD changer controller? Is that just to add a CD changer at a different location?
Also, the XM radio only displays 16 characters of the artists name or song title. In the manual it mentions holding the 'text' button for a few seconds--but that doesn't do anything. Is there a way to set it to more characters or have it scroll?

Thanks,
Richard