U101 lost communication with tcm

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 ?

Check to be sure all pins are seated and locked in the two ECM connectors removed during DSP5 switch install.it is possible for these to not have gotten locked in from the factory. Had this happen to me on a kodiak except it was oil pressure sensor wire and gauge read zero all the time.

yeah ive checked them push pull