The nav enabled head unit communicates to the CD changer using a Becker protocol that looks much like the sony unilink interface. It requires several messages to be sent back and forth before it will recognize the CD changer. Then to keep link active the head unit and cdx continue to "talk". I have yet to find any company selling a unit which works with the Becker/infinity unit found in the crossfire. But the short answer is it is not simply applying a voltage to a pin and pulling the line in/out off the mini iso jack.

I have successfully made a custom interface that works but have no plans to make it commercially available. I now need to find how to pry off the plastic trim to get cabling back to the storage box in the center console

--Darrell