I understand the instruction on doing the bypass however with the bose system and onstar in my 2008 GMC Dually the GMOS-LAN-02 instruction has you hook the Brown wire from the 14 pin harness to the mute wire on the D3 harness. It also instructs to attach the green wire of the 14 pin GMOS to the parking brake wire of the D3 harness. If I do it this way then obviously I will not be able to do the bypass. I could add another wire to the empty pin location that the mute wire would go into and ground it, but without the green parking brake wire being grounded it would not work I think????? SO HELP. if anyone has bypassed a CHEV/GMC WITH ONSTAR AND BOSE PLEASE FILL ME IN.

The mute wire connection would be so that OnStar can mute the radio when using it's features. However, the parking brake connection is probably just to meet the same requirements that Pioneer makes about connecting that wire. I think you can safely ground the D3's parking brake wire rather than connecting it as in the instructions. As you said, you'll still have to provide a separate grounded wire above the mute wire's position.

I understand the instruction on doing the bypass however with the bose system and onstar in my 2008 GMC Dually the GMOS-LAN-02 instruction has you hook the Brown wire from the 14 pin harness to the mute wire on the D3 harness. It also instructs to attach the green wire of the 14 pin GMOS to the parking brake wire of the D3 harness. If I do it this way then obviously I will not be able to do the bypass. I could add another wire to the empty pin location that the mute wire would go into and ground it, but without the green parking brake wire being grounded it would not work I think????? SO HELP. if anyone has bypassed a CHEV/GMC WITH ONSTAR AND BOSE PLEASE FILL ME IN.

I am here right now what did you end up doing with the Brown and Green wire from Gmos?

While I don't have Bose (don't think it matters), to keep the Onstar mute intact all you do is add a wire to the now-vacant spot in the terminal and connect it accordingly. I think I have a thread here somewhere with more hard, specific info on it.

While I don't have Bose (don't think it matters), to keep the Onstar mute intact all you do is add a wire to the now-vacant spot in the terminal and connect it accordingly. I think I have a thread here somewhere with more hard, specific info on it.

Perfect that was the info I needed!