Not sure if this adapter has been mentioned before and if so I had missed it. PAC makes an adapter to bypass the Bluetooth module when installing an aftermarket head unit with its own built in Bluetooth . I installed a car-joying unit and all my steering wheel controls worked except for the two button for send and hangup a call. Once I used this I was able to map out all the buttons.
http://pac-audio.com/catalog/specialty-items/bt-swc-ni1
I purchased it through Volunteer Audio: PAC ? BT-SWC-NI1 ? Volunteer Audio
http://pac-audio.com/catalog/specialty-items/bt-swc-ni1
I purchased it through Volunteer Audio: PAC ? BT-SWC-NI1 ? Volunteer Audio