2014 Sierra .
i completed this grounding issue on mine today (in the dash near the speaker), these was no such issue with the insulation, and further inspection revealed the stud is crimped thru the dash so even if the Dash insulation was between the terminal and the bottom of the stud, it would not make a different unless the nut was not tight to make the opposite side non-conductive.
i have the same issue and now going to look further into the issue,
driving down the road it defiantly seems like a short or loose ground.
i have owned this truck over a year and never had this issue. the truck has 120k on it. the only differential items that i have done with this truck within a few days of the first and second occurrence everyone here is describing is:
traveled about 200 miles with the instant gas mileage computer on set to last 25 miles ( not likely but could contribute to PCM heating up) AC on set to 70 and it was about 80 deg out
towed my camper about 150 miles prior to the issue. ( trailer brakes only used 3 prior times with no issues) not likely an issue since i was not towing at the time of the issue.
first issue happened about 30 miles from home, i was slowing to make a right turn all gaugesin the dash including the Navigation blinked and truck stalled to a rolling stop ( lost steering). turned key off started right back up as if nothing happened,
second issue same day as first about about 40 miles down the road driving down highway, twice i turn on the left blinker and the stability error comes up, for the entire trip if i turned on the left blinker it disengages the cruise control, the right blinker has no effect on the cruise.
if i find any smoking guns on this issue i will post back here.
if i get in an accident before its fixed or recalled, my lawyer will likely be back here for statements and testimony, since there are many that can document this issue and no recall.
does GM really think this will go away on its own without deaths and law suits???
My bad found a recall, let see if they honor it.
"GM Product Safety Recall 17276 Loss of Steering Assist"