2012 Bluetooth mic to aftermarket head unit

I'm looking to wire my alpine Ina-w910 mic input to the factory Bluetooth mic between the map lights but can't seem to find any pinouts or wiring diagrams for the factory mic. Has anyone done this mod or have the pinout for the mic harness??

 

Any luck on this? Looking at a Pioneer and was told the same thing. Sure would like to be able to use the same mic (and BT steering wheel controls).

mike

 

Ended up with the Pioneer Avic=z140. The audio install guys couldn't get the factory bt mic to work.