i have a 2011 panel, the radio works fine, for the most part, i can tell when part of the speaker system drops out tho, i can still hear it fine.

the problem i'm having is bluetooth and onstar are so quiet (i've turned the radio up all the way) i barely can here directions or phone call.

anyone encounter this? local dealer ship wants $99 just to diag it.

 

You say part of the speaker system drops out, but you can still hear it fine? Are you saying you have intermittent speaker problems where they stop working?

You might want to investigate replacing the defective speakers first. Speaker failures are not an unknown occurrence.