I bought this 2020 2500HD 6.6 Gas last August and within 1000 miles one afternoon it wouldn't start. I hit the start button and it cranked for probably 10 seconds and stopped. I tried it again and it cranked for about 5 seconds, tried to start but then sputtered and died. I went through the Chevy app for service and they sent out a tow truck about 30 minutes later. He sees my truck and says "3rd one this week, I know what to do". He hooks up a jump pack and it fires right up but my check engine light stays on. I setup a service appointment with my dealer the next day and they load test my batteries...no issues (my service engine light went off on the way to the dealership). The service dept. told me the only thing they could think of was that I tried to start it while it was performing an automatic update (I have sense seen the little update announcement flash up on the screen 2x now and avoided trying to start it).

2 months ago, my wife tries to start it and it does the same thing. Again, nothing is found to be wrong with the truck.

Fast forward to last week and now about 13k miles on my truck, it does the exact same thing again. It finally started on it's own after I waited about 10 minutes after the failed attempts.

In each instance the check engine light comes on for about 24 hours and then goes away. Anyone else experiencing this issue? My dealer says they aren't aware of any known problems.

 

Yeah been having the same issues with my 2020 Chevy 2500 6.6 gasser … I thought it was the different kind of fuel I was using then I been trying to use the same fuel from Mobile Exxon fuel seems like the problem went away now within the last two weeks same issue then I get it fired up and then the check engine light goes off I wonder what the deal is with it… any advice would help

 

I finally wound up taking my truck to another dealer, not the one I bought it from. They found that there was an update needed for the fuel flow and that fixed it. So take it to a dealer and tell them to check for updates