I have a 2012 that had no tow wiring at all. I don't know the sales codes, but apparently there is a towing package that includes everything (wiring and hitch receiver, along with other upgrades), then there is tow-ready package which includes unlit wiring under the rear bumper. Look around inside the rear bumper and you should see some wiring and a connector. If you have this, you are in luck. Just add a receiver/hitch and there is an adapter to adapt from this wiring harness to a 7-way and 4-way connector. You will need the dealer to enable the wiring by doing a flash. There should also be a plug socket under the dash to plug in a brake controller.
If you don't have a wiring harness under the bumper (like mine), it is much more complicated and if you DIY, consider it carefully; this could easily take a full weekend. The factory upgrade kit is here:
Wiring Harness #82212196AB
You can see the installation instructions there, too, which involves removing the TIPM
. This requires a re-flash, too. I don't know if this kit includes a brake controller connector.
This vendor also has a factory hitch receiver that fits in the rear bumper if you don't want the aftermarket look.
I learned all of this after my installation, which is completely aftermarket. It cost a little less, but if I had known all this beforehand I would have gone factory upgrade on the wiring and the hitch and paid a couple/few hundred dollars more. Hope this helps someone else.