3.0 Duramax won’t start

[Ajt116]

Hello,

 

About a month ago I went to start my 2020 Sierra with the 3.0 duramax and it would try to start, immediately stop and then say Engine power reduced. It would proceed to not let me start it for about 30 minutes and then it finally started in which the check engine light was on. I drove it to the dealer immediately and they said they couldn’t find any issues besides a code stating it was jump started, and I never jump started it before. It was fine for about a month until today, where I went to start it and it did the same exact thing. I had to end up just leaving it, making myself late for work and now it’s just in a parking lot sitting. Has anyone experienced this before, or seen other threads with “Engine Power Reduced” for no apparent reason? It has all the fluids, plenty of DEF, etc? It only has 3k miles, it’s 2 months old, and already done it twice. I can’t keep having this truck keep me stranded, late for work, and just unreliable.

[BurnsMax]

It is probably a bad battery.  I have seen a lot of people with a bad battery causing an issue with starting and a CEL.  I would have the battery load tested.  It probably has some dead cells and needs to be replaced.

[steve841]

Look here for the TSB referencing loose fuse block posts. Was causing various issues on gas motors.

 

it’s a stretch, but can’t hurt to check them.

[steve841]

Here it is..