Wierd intermitent problems

[cottonflash]

I have an 07 Envoy Denali 65k. I have the following problems on and off, cruise won't turn on, shifts hard from 1-2 2-3, and rough acceleration from 1500-2000 rpm.
I thought I had resolved the problems when I found a loose cable/wire from battery to main fuse box on drivers wheel well. All my issue disappeared for a few monthS and now have returned. I checked the cable/wire and it is not loose.
ANY IDEAS???

 

[GMC Customer Service]

I'm sorry to hear about all of this Cotton. If you're unable to find the culprit on your own your dealer should be able to take care of you. You've got an 07 with 65 thousand miles (which should put you within your powertrain warranty) so you may be covered for this, under normal circumstances. If you do end up taking the vehicle to your dealer let me know and hopefully they can get you taken care of.

Jeff Morris, GMC Customer Service

 

[cottonflash]

Tcm

I need to replace my Automatic Transmission Control Unit apparently. How big a job is that an 07 Denali v8 4spd? Anyone know about what they should cost?