Help, Trailer Wiring Harness!!!

[Lambeau]

I'm in the process of installing the BMW wiring harness (2006 3.0) and for the following step...
"Clip the trailer module onto the plastic carrier plate. Connect the black 15-pin socket housing to the trailer module."
It will not clip in, you can see that the module is designed for a different recepticle. Yes it has 15 pins but the notches in the module do not match the socket housing. The wiring harness is correct and connects to the existing wiring but this module does not. Anyone have any ideas??? Is this "module" required??? It is apparently a device intended for something. This module socket housing is located right behind the battery.
THANKS!