I have a 2007 Suburban in which I recently installed a factory nav. I ordered and received the JP Customs VSS kit and will be installing that shortly in order to combat the nav systems failure to respond to being off course. However, I would like to hook up the voice recognition but I seem to be reading conflicting threads. Do I need a plug with three wires to hook to the back of the OnStar box or do I just need to tie into a couple of the wires (grey and blue, I believe) as seen in another thread (https://chevroletforum.com/m_15129/tm.htm)? Also, does anyone know what the various pins are for in the OnStar module? Thanks!

 

Maybe this will help you? Try posting this in the tahoe forum, they get more hits over there.

How to install OEM Nav on 2007 Tahoe