Yup, plug in the "Nav SD Card module" which is 2-3 wires, then check the glovebox to make sure that special cable is also plugged in per above mentioned thread.
I did the same thing. I installed the nav module my self. The only issue I had was not realizing that I had to connect the wire in the glove box and was not getting a gps signal because of it. Had to call the service dept. for the answer.