2014 GMC Sierra randomly shutting off while driving

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jburke585
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2014 GMC Sierra randomly shutting off while driving

Post by jburke585 »

I have a 2014 GMC sierra SLT with the 5.3L with roughly 50k miles on it. I tuned my truck about six months ago and have no issues till this past month. I am just running the 87 octane stock tune with a little firmer shifting on the transmission. I also have a little big bigger tires in stock so I modified my tire size with the Diablosport inTune i2.

About a month ago I was pulling out of my drive way and the truck suddenly died. Engine shut off and from what I remember all power was lost as well. I really didn't think much of it at first and thought maybe it was just some bad gas, and I would fill it up next time with better quality gas. (NOT JET-PEP TRASH).

Fast forward a couple weeks and the truck has done it 5 more times within a span of about an hour. It would happen when accelerating from a stop, and also moving down the road. Which can be quite scary to lose all power going 55 mph.... It has recently been very cold lately (10-30 degrees F). I don't really see how this can effect it though since it seems to do this after the truck as warmed up and when it is cold.

I researched this as much as I can on the GM and Chevy forums and found no other similar issues so I figured I would try these forums. I checked the basic problems(loose battery terminals, loose grounds, etc.) and found no issues. Do you guys have any recommendation on what the problem would be? Can the inTune i2 gather some logs or info on what is really causing the issue?

I am thinking about removing the tune from the truck and going back to stock as a starting point. I don't really want to take it to the dealer yet since I do have the tune and it is very intermittent. They will most likely tell me its normal and go on my way. The only mods I have on my truck is a rough country level kit. I have not modified anything electrical on the truck.

Any help would be great. Thanks.
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mikel
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Re: 2014 GMC Sierra randomly shutting off while driving

Post by mikel »

You could record a log and hope to catch it happen, but you may need to see more/different PIDs than the default list to really see whats happening.

We had lots of issues on our 14 Sierra with the plug wires AND coil pack connectors. On multiple occasions they would come unplugged seemingly on their own and we often had plug wires coming off the coils as well. Definitely start there.
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06MonteSS
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Re: 2014 GMC Sierra randomly shutting off while driving

Post by 06MonteSS »

yeah it's not a tune issue at all. it's something physical/mechanical with your truck... check plugs, plug wires, coils as mentioned.. make sure everything fully and securely snapped on/connected..
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