Well on this drive light most my check engine light came on. I have a 2016 GMC Denali diesel 3/4 ton PU 41k miles. Its been in six times in the last 18 months for a check engine light. Its always a air/ emission sensor of some sort. I think there is a short somewhere. I'll take it out in the next couple days and talk to the service manager this time. I'm tired of it. Love the truck, just fix it.
Yep, get her fixed. Although not a 100% diagnostic tool, The OBD2 system with all their generic and manufacturer specific trouble codes really helps with the diagnosis. It can narrow down the problem in many cases.