2023 Yukon Denali Ultimate mystery codes

[ninjaplumber]

UPDATE: The 2023 GMC Yukon XL "Ultimate" is DEAD AGAIN! Less than 2 months and 2,000 miles after the dealer replaced the lifters under warranty, this giant POS has the exact same problem. This time is especially painful as I'm stranded out of town with the family and a trailer. Effff you GM!!!

I am a firm believer that whenever lifters are replaced that the vlom needs replacing also. I had lifters changed 3 times in a 2017 denali. Vehicle had just over 68,000 miles. I paid over 8 grand the first time. The 2nd time it registered just over 1200 miles. The 3rd time just over 1200 miles. The solenoids may test good buy not guaranteed. Vlom replacement is the cheapest part of the whole process. Vehicle has since been running great.

 

[yourmomsshlong]

I wonder if I could insist on this, this time around. Since it's still covered by the original warranty, it would seem GMC wouldn't want more repeat expenses.

 

[Tahoe14]

Or just a new replacement vehicle provided by GM.

 

[yourmomsshlong]

Everyone kept saying it wasn't going to be a problem on later '21s, then it wasn't going to be a problem on '22s, now '23s are failing...all blaming parts suppliers...I think its safe to say at this point it is a systemic design issue (likely related to cylinder deactivation)...can't wait for a class action lawsuit.

It's definitely the AFM B.S. that provides very little upside and all downside to us, the end users. AFM's only benefit is the good boy points (or girl, Mary Barra) earned by General Motors from hand wringing, ESG obsessed corporate aholes. A simple, solid chunk of metal instead of spring loaded idiotic lifters solves 100% of these issues, but I digress.

 

[swathdiver]

UPDATE: The 2023 GMC Yukon XL "Ultimate" is DEAD AGAIN! Less than 2 months and 2,000 miles after the dealer replaced the lifters under warranty, this giant POS has the exact same problem. This time is especially painful as I'm stranded out of town with the family and a trailer. Effff you GM!!!

Looks like an injector, not a lifter problem to my eyes.

 

[yourmomsshlong]

Looks like an injector, not a lifter problem to my eyes.

That would be great, my gut says otherwise, and I'll update after diag.

 

[swathdiver]

That would be great, my gut says otherwise, and I'll update after diag.

They tell pilots in flight school to trust their instruments. We shall see.

 

[Geotrash]

That would be great, my gut says otherwise, and I'll update after diag.

So what's the latest? Did they get it figured out?

 

[yourmomsshlong]

@swathdiver called it. Also, check out dealer #2 trying to throw dealer #1 under the bus:

 

[WalleyeMikeIII]

@swathdiver called it. Also, check out dealer #2 trying to throw dealer #1 under the bus:

I'd say it was justified if Dealer #1 didn't actually re-secure the engine wiring harness...lots of vibration up there...important to tie down the wires properly.