06 tahoe will not connect to pcm

Hello,
I am trying to install a t1000 in a 06 chev Tahoe with a 5.3 in it. When I plug in it turns on select tune and comes up with can not connect to pcm.
I did the down load and updates on the trinity tested in a 05 dodge diesel works fine I know its not your unit any thoughts though? it does have a big audio system in it I did take out all the fuse for that but still no go. any help would be appreciated

[mikel]

disconnect the aftermarket stereo harness from the vehicle harness and try it again.

Be sure you selected the vehicle in the options/change vehicle type menu.

Thanks

[garrett]

Be sure to disconnect any aftermarket radio, amplifier, trailer brake, etc then try the process again.