there is a setting in the radio called speed vol.it might only get info as soon as the car is put into gear. so try setting it at a different level just to see if it helps.and if you have it on already, turn it off to see if that works.if all else fail do this.
1 have the am or FM on.
2 push and hold preset #3&6 at the same time.(this will put the stereo into a speaker test)
3 quickly push the #2 preset.(i think this is the self test.)if it is not 1-6 presets do or show different things. just hope it will say no error or no dtc
if it dose have a dtc there is a way to clear it. and to exit this mode just turn the radio off and it comes on as normal
good luck, hope this helps.ps i think it is the eject button to clear the dtc.
2007 mustang gt premo/alloy grey on dove int/hurst shift/gt500 pedals/
sequental tail lights/2008 ceter concel with lite ring/mustang lit door sills/frpp push start/20x8.5/20x10 blackcrome bullit motorsports/
cdc chin spoiler/saleen H.I.D. headlights/steeda udp/oem nav/
factory side scoops/gt500 rear bumper/saleen 12in. sub/frpp bullitt cai/frpp bullitt strut bar/frpp x pipe/magnaflow cat backs/
oem nav/and more 2 come [but are we ever realy done?]