I had similar shutoff issues with my 2015 Silverado. I followed instructions to check the two ground wires connections under the dash, sure enough they had some insulation stuck under both sides. I cleaned them up and though I had fixed the issue..... Unfortunately not! the truck continued to reset and shutoff while driving. Then I found this ground wire behind the right front wheel well. I removed it to find that the undercoating was between it and the ground wire!!!! hello GM!! I cleaned it all of of the connector and the truck and reconnected. 3 weeks later what was a daily issue has not re-surfaced. hope this helps some of you, this is a dangerous problem.