I have a 2005 g35 hard shifting 1st and 2nd I ran my obd on it came back saying the out put speed sensor so I replaced that and still doing the same thing and I googled it and it said that the TCM was no good to make a long story short I started replacing the TCM and when I took out the valve body I noticed there was a plug not plug in so I plugged it in and drove it like 3 miles and now it won't move at all what is that plug do why was it moving when it was unplugged and plugged up it won't move thank you for your help

It's the one that plug into the TCM with the green blue and yellow wires