Anyone else out there ever experienced this ? What did you have done ? Did it correct it ? Need some help guys, my 05 "chuggles" (yes, that is the word GM uses) at highway speed under a light load. I've done a ton of research and Have come across a TSB that describes my problem accurately. The repair calls for the TCM to be reprogrammed. How is it done ? What cost can I expect ? Thanks in advance.