2021 Duramax problem already

[John V Carlson]

Well I swore I’d never go back to GM and I should of stood by that.
2021 RST Duramax with 1k miles. Went to move the Tahoe from the street to the driveway tonight and it wouldn’t start. Truck kept turning over but wouldn’t fire up! So now I gotta wait till the dealer is open tomorrow and have this pos towed there. Love the way it looks love the interior but facing a no start at 1k miles is unacceptable.
Anyone else having issues with the Duramax ?

My ‘21 Yukon Denali Duramax with 3K miles has been flawless. Averaging 30.1 mpg. Amazing!

 

[Brett776]

My ‘21 Yukon Denali Duramax with 3K miles has been flawless. Averaging 30.1 mpg. Amazing!

That’s good ! Hopefully mine has no more issues. I enjoy the mpgs though I’ve never gotten that high. Love the motor just need it to start every time.

 

[fasteddy]

My ‘21 Yukon Denali Duramax with 3K miles has been flawless. Averaging 30.1 mpg. Amazing!

Averaging?
Like 20 city and 40 highway?

I got to get one of those.
Do you have to put that DEF stuff in it?

Can't wait for the tuners to come out with "> mpgs" tunes and "crank up the boost" tunes

 

[Stbentoak]

I can see them potentially pushing 30 on the hwy, but I bet daily reality is more like 23 ish in mixed driving. Still pretty stupendous for this huge of a vehicle.
Also as a fun fact, people always say it will be better when it breaks in... but most people don’t realize that break in for diesels is usually 40-60k Miles plus...less if you tow....

 

[sc00ter_17]

I was given a 2021 Tahoe LS with the Duramax for my work vehicle and overall I love it. Fuel economy is surprisingly good. I average around 30-32 mpg with 80% highway and 20% city driving. 50 mile best is 38.2 mpg. Unfortunately it has been to the dealership twice with only 2,300 miles on the clock. First visit (@ 400 miles) all they said is a sensor failed and was replaced and now this second time (@ 2300 miles) they said it was something with coolant flow and it had to be reset and relearn the flow rate. I hope this isn't a sign of things to come.

 

[Pickerelguy]

Well I swore I’d never go back to GM and I should of stood by that.
2021 RST Duramax with 1k miles. Went to move the Tahoe from the street to the driveway tonight and it wouldn’t start. Truck kept turning over but wouldn’t fire up! So now I gotta wait till the dealer is open tomorrow and have this pos towed there. Love the way it looks love the interior but facing a no start at 1k miles is unacceptable.
Anyone else having issues with the Duramax ?

I am at 9,000 miles, same thing, turns over but does not fire. What did you find out, not too happy.

 

[StephenPT]

I am at 9,000 miles, same thing, turns over but does not fire. What did you find out, not too happy.

Did you try starting it again after the first time it didn't start? Sounds like there's quite a few reports of 3L Duramax cranking for a long time and then timing out. The second time seems to work for most people. Also, it sounds like there's a software update being applied for this issue and those that get the update don't have the issue anymore. See below thread for more details.

3.0 Duramax with crank no start

I experienced the dreaded crank no start. Truck timed out, but then started right up on second try. Drove straight over to GMC dealer, found ECM update regarding crank no start. Have no experienced it again, but it does crank longer by default now. Just thought I would share for others that have ...

www.gm-trucks.com

 

[Stbentoak]

Yep, there’s a software patch to fix this. It’s not a show stopper. It may not do it again for another 5000 miles. If it bothers you take it in and have them apply the patch.

 

[Brett776]

Happen a third time, show stopper for me when it makes me late and miss a flight or late to my kids daycare. In my experience I could try starting it 100 times in a row and same result. This last time the constant starting killed the battery and I had it towed to a dealer. They replaced the battery and said it was the battery, I argued the batteries dead cause it wouldn’t start, they argued the contrary. They never looked for the TSB patch until I walked in and pointed it out. We will see if this fixes it. It does start differently now. After the tow I test drove the wagoneer and grand wagoneer. Loved the interior, Hated the outside and the amount of money to get decent specs. There were ten on the lot compared to zero tahoes if that tells you anything.
Ultimately I love the Tahoe, just frustrated having issues with a new truck. Hopefully it’s fixed because it’s the best looking full size suv right now.

 

[Stbentoak]

You've got more issues than the normal "No Start" person, along with a dealer that doesn't have a clue. I've never seen on any forum a vehicle that cranks till the battery is dead. Try another dealer... But if you got the patch you should be fine now.....