I have an 07 Nissan Frontier and recently had to change the TCM, after replaceing both the TCM and all the Transmission shift Solenoids I had ended up (cherry on top) Losing the Key. (which is of course chipped). I ended up having a locksmith come out to program a new one (200 bucks on top of the already 220 for TCM and Solenoids) and when he tried to progam the key but the OBD ii Port wouldnt respond. No codes thrown, no message except from his computer that stated that the port wasnt responding. I checked the Fuses and none were Blown. When i Looked under the Dash at the port I seen the extra ports coming off the side of the wiring for the OBD ii port but after a little researching I figured out that at least two of them were for other options that my truck doesnt have. Its the Third port that i Found that bothers me. It looks as if 2 of the wires off the side of the harness that connecting to the OBD ii port have been spliced into and a smaller port is connected to those. I will post Pictures asap, but the third port wasnt connected to anything and I have found no other plug that it might go to anywhere under the Dash.