Just looked at the photos of the 06 radio off GMC's site. Looks like they changed the controls around a bit. On mine the RCL button was in the center of the tuning ****. My first inclination would be to try doing this procedure but pushing that button. Looking at the old photo of my factory radio though...it has a separate info button where your radio has the "type" button with those two arrow button surrounding it.

If that fails, choose a few other buttons to try it with. That "type" button between the two areas might be a good candidate.

 

I called my dad...he has an 05 duramax with the same radio...

Im having him try the main radio station that I listen to, to see if his does the same thing.

The difference is that he bought his at a different dealership.... I am curious if the dealership was feeding me a line or not.

My dad did say the samething your telling me...holding the "info" button for some amount of time. Its the button inside the volume or tuning ****.

My dad hasnt ever noticed it, but he generally listens to XM.... and I never paid that bill to continue the service....

Thanks endo.... I am going to try it tomorrow

 

Welp, I tried the "info" button and it really didnt do anything.... actually I dont think it did anything, but with the radio volume almost off I heard it beep at me. But it still does everything the same....

I guess I will end up getting another head unit....

Ill have to up grade to the fancy stuff..... dvd player and all that jazz....
woo hoo! an excuse to up grade

 

That's pretty lame. My Dad has an 06 Silverado with the stock HU in it...I'll try to have a look at it next time I'm over there and post back, but it could be a while.

 

Was over at my Dad's tonight and figured this out....

The way it works is:
* pushing the info button cycles through different display modes. I think there are three modes, frequency (what you want), text, and something else. I have no idea what "something else" might be....on my Dad's it always said "None"
* HOLDing the info button in selects the default mode.

So what you do is push INFO until the frequency shows up, and then hold it in 'til it beeps.