Here is the you should look for in an E39 electrical schema, followed by the best sources to obtain it.
A top diagram includes a showing that pin X6000 is a 26-pin black connector on the GM (located behind the glovebox). Pin 2 is the 4th pin from the left on the top row. schema electrique bmw e39 top
Search for "BMW WDS E39 download" or "BMW E39 electrical troubleshooting manual (ETM) 2003" – that is the true "top" schema you are asking for. Here is the you should look for in