I tuned a customers LBZ 07 traditional with a dsp5 tune and now he has a u101 lost communication with tcm code and when shifted to M it stays on "6" he cant manually shift it.Now the check engine lightcomes on intermitantly but the Manual shift is consistant. I tuned this truck two weeks ago and didnt notice this when i was done but 10 minutes after he left he called me to tell me this. I drove the truck the next day and the light was off and i could shift manually, i brought the truck back to him and when i went to show him all was well the light came back on.No matter if the light is on or off you cant manually shift. I have this same exact tune on my personal truck an 06 and have no problems i just made a script and put it on his. I have taken the switch back out and put his stock tune and os in and it didnt fix. Im not even sure this was something i did but he thinks i did so im trying to get it figured out. Truck runs and drives great except he cant manually shift. i tested for continuity across two pins of the tcm and have continuity(saw to check that somewhere) Any Ideas? any one had same problem? Help ?