At first look, Is your Sirius Radio activated? Are you receiving any or all Sirius channels? I suggest you call them if you have not and have them send your radio a signal. Sounds like an activation issue not any Nitro equipment failure. Let us know what you find. Good Luck!
Nitro Year: 2007 (1 of 91,815 sold in 07)
Nitro Model: R/T 4X4 Stone White
CAT-BACK Exhaust, CAI, Projector Head Lamps
Fully-Equipped w/all factory options