This is a message from GROM Support:
" When you installed the GROM device did you disconnect the Factory satellite tuner? It has to be disconnected at the tuner itself not at the stereo. If this has not been done please do so this should help with issues you are having."

How do I disconnect the SAT tuner from my 03 coupe?
Im having troubles because sometimes the stereo does not recognize the GROM box.
I removed the SAT plug from the stereo and plugged the GROM cable.
I can play music through my phone now but I can't skip the music using the steering wheel control (all I can do is adjust volume) the "bluetooth dongle" does not work too but I can pair my phone with it, its just that my phone says that music is playing but no music can be heard.
What else should I do? Do I remove the SAT box or whatever? Where is it located?

 

It's in the trunk, left side, under the floor board. Just unplug it.

 

The sat box by the spare tire, as part of the metal bracket seen here, it will say SIRIUS or XM on it. (ignore the red box, it's identifying a harness) Just unplug it.

 

It was already unplugged
And also, when I press the SAT button on the radio, SOMETIMES it says "NO SAT"

 

are you running the most current firmware? I had a lot of issues with not even being able to cycle into the grom unit when using the most current firmware. Try reflashing to an older one. check the unit of the box and email grom and ask which firmware would be best with the model you are using or just keep guessing and checking.

 

I just installed the GROM AND2 and have the same issues. Do I need to disconnect the SAT harness in the trunk AND disconnect the original SAT connector from the female GROM SAT connector?

I have a '05 5AT Coupe.