p1815 code changed to no error then 1st gear power reduced

Hello forum tech's.
I have a 2007 TBSS that I'm running a 4l80e with a stand alone us shift 4 controller. In order to get my cruise control to work I have had to disable all trans error codes "p0787, p0973, p1815, p2764 and p2769" by changing them to no error reported. When I do this to p1815 code it produces a major post 3k rpm power loss. Could someone please point me in the right direction to keep this from occurring? I've tried numerous things with no success. Thank you very much for your time.