Does anyone know which OBD port pins are populated on a 2006 XK8? there are two rows of 8 on it.

 

First place I would check is the Electrical schematic document from the JTIS. Now, it only has up to 2004 MY, but more than likely it is the same. Do you have the JTIS? If not, check the FAQ thread for a link to it, or separate links in Gus's section for electrical links. If all else fails, send me an email and I'll reply with a PDF from my home computer.

 

According to the '04 wiring diagram, the following pins on connector FC53 are un-used:
3, 11, 12, 13

Note that I said un-used

 

I thought every OBD-II port in every car in the world was standardized. Why do you need the pin-outs for the port?