4L80E Transmission troubles, DTC 86

[Mogman]

Do the Tcm stand alone with the transmission? Or?

I do not understand your question, the TCM only controls the transmission

 

[Terra1936]

I have a non running 1123 and was going to pull trans and put in my 998 and wanted to use the Tcm and original harness. But I did not know if the harness needs engine feedback?

I do not understand your question, the TCM only controls the transmission

 

[Mogman]

I have a non running 1123 and was going to pull trans and put in my 998 and wanted to use the Tcm and original harness. But I did not know if the harness needs engine feedback?

Yes, it needs RPM and throttle position, would be very hard on a 6.2L not so bad on a 6.5L, IIRC all of them come with a crank sensor.