2022 Yukon Denali Diesel fuel injector failure

[Barnum]

Had a fuel injector fail at 23k miles on my duramax on the interstate on Memorial Day. All the bells and whistles went off, check emission, real axel alert, real weird codes for the reported issue. Did not see any other posts on this on the forum but also know diesels are a minority here (checking to see if bud light will make me a duramax can) Part will be here Saturday fixed on Monday. Anyone heard of any issues? Hopefully it is a one off.

Thank you

 

[StephenPT]

Did they tell you which injector # failed? There's a TSB for the wiring harness on injector #2 getting pinched by the noise insulation shield. Not an actual injector failure, but the service procedure tells the dealership to replace both the wiring harness and injector along with shaving off the foam from the noise insulation that causes the pinched wiring.

https://static.nhtsa.gov/odi/tsbs/2022/MC-10211935-0001.pdf

https://static.nhtsa.gov/odi/tsbs/2022/MC-10208993-9999.pdf

 

[Barnum]

Did they tell you which injector # failed? There's a TSB for the wiring harness on injector #2 getting pinched by the noise insulation shield. Not an actual injector failure, but the service procedure tells the dealership to replace both the wiring harness and injector along with shaving off the foam from the noise insulation that causes the pinched wiring.

https://static.nhtsa.gov/odi/tsbs/2022/MC-10211935-0001.pdf

https://static.nhtsa.gov/odi/tsbs/2022/MC-10208993-9999.pdf

Thank you for the information, I will ask and report back.

 

[Barnum]

I received her back yesterday. It was actually cylinder 4. Mentioned a loose wire that caused a arch, short that took out the injector. No idea how the underpinning of diesel fuel injectors work. The dealership, two hours south of tampa treated me like gold Mike at Dixie GMC in Ft Myers Florida was first class. It sucks having a dead stick two hours from home coming back from a family vacation.

 

[Stbentoak]

I received her back yesterday. It was actually cylinder 4. Mentioned a loose wire that caused a arch, short that took out the injector. No idea how the underpinning of diesel fuel injectors work. The dealership, two hours south of tampa treated me like gold Mike at Dixie GMC in Ft Myers Florida was first class. It sucks having a dead stick two hours from home coming back from a family vacation.

Dixie is my dealer in FL when I'm there in the winter. They don't know me from Adam and have done the majority of warranty work on my vehicle at no charge and with a smile. For all the bashing most dealers get, these guys have treated me well also.

 

[yourmomsshlong]

Just had the same thing on my 2023 Denali Ultimate 6.2, 2 months after a lifter collapse. Bad injector on #6 cylinder. The codes are really weird. About to order a 2024 Ultimate XL with LM2 diesel hoping to avoid engine issues, so this is worrisome.

Had a fuel injector fail at 23k miles on my duramax on the interstate on Memorial Day. All the bells and whistles went off, check emission, real axel alert, real weird codes for the reported issue. Did not see any other posts on this on the forum but also know diesels are a minority here (checking to see if bud light will make me a duramax can) Part will be here Saturday fixed on Monday. Anyone heard of any issues? Hopefully it is a one off.

Thank you

 

[DuraYuk]

Just had the same thing on my 2023 Denali Ultimate 6.2, 2 months after a lifter collapse. Bad injector on #6 cylinder. The codes are really weird. About to order a 2024 Ultimate XL with LM2 diesel hoping to avoid engine issues, so this is worrisome.

Enjoy life. Anything human made can fail. Doesn't mean it will

 

[Morbo]

Had a fuel injector fail at 23k miles on my duramax on the interstate on Memorial Day. All the bells and whistles went off, check emission, real axel alert, real weird codes for the reported issue. Did not see any other posts on this on the forum but also know diesels are a minority here (checking to see if bud light will make me a duramax can) Part will be here Saturday fixed on Monday. Anyone heard of any issues? Hopefully it is a one off.

Thank you

My 2022 Yukon Denali Duramax is in the shop now for a new injector for cylinder 5. It went out with about 25,000 miles on the odometer and did the same thing your's did with all the bells and whistles going off. Will post details when I have the paperwork on all of the work they performed.

 

[Jay P Wy]

Both the 6.6l and 3.0l diesels use a Denso fuel system. GM went to the Denso system after all the problems with the Bosch CP4 high pressure injection pump failures on the 6.6l. There have not been many issues with the Denso fuel system on either Duramax. They stopped using the Bosch fuel system in 2016 (L5P in 2017 was the 1st gen 6.6l to use the Denso fuel system).

 

[UsualSuspect]

Both the 6.6l and 3.0l diesels use a Denso fuel system. GM went to the Denso system after all the problems with the Bosch CP4 high pressure injection pump failures on the 6.6l. There have not been many issues with the Denso fuel system on either Duramax. They stopped using the Bosch fuel system in 2016 (L5P in 2017 was the 1st gen 6.6l to use the Denso fuel system).

The 6.6's were the LB7's and it was the injectors, and the 2011 to 2017's with the CP4's. The LLY, LBZ, LMM, and LML saw very few failures from injectors or pumps. My son's LBZ, I bought it new, handed it down to him, 350k and still running the original injectors and pump. LBZ's were last non-DPF, non-DEF 6.6's built, and are sought after due to their reliability. Those 6.6's used the Bosch HPCR, which was a CP3 gear driven pressure pump. In 2011 the LML Duramax was introduced, which used the CP4 fuel system, and a new piezo solenoid injector, both were prone to issues.
The L5P has a Denso HP4 pump, which can't produce the rail pressures the CP4 and CP3 did, the injectors were changed from a Bosch Piezo (Used from 2011 to 2016), to a solenoid type produced by Denso to accomodate the lower fuel rail pressure of the HP4 pump.

 

[Jay P Wy]

The 6.6's were the LB7's and it was the injectors, and the 2011 to 2017's with the CP4's. The LLY, LBZ, LMM, and LML saw very few failures from injectors or pumps.

LMLs had the CP4 and saw lots of pump failures. I have had all but one gen of the 6.6l (LLY). The LLY, LBZ & LMM had issues with running hot when towing at or near towing limits because GM didn’t put a big enough radiator in (fixed starting with LML). Ford still uses the CP4 and Ram recalled all the Cummins that had the CP4 and replaced it with a modified CP3. FYI the Denso pump is a 2000 bar pump (29000 psi). The CP3 is a 1600 bar pump and the CP4 is up to a 2000 bar pump per Bosch. I know GM, Ford and Cummins all operated the CP4 above that.
I agree that the LBZ was a good (if not best 6.6l due to the lack of emissions). The one I had was sold a 390k with no engine/trans issues.

 

[StephenPT]

Just an FYI - LM2/LZ0 use the Denso HP5 (2500 bar) with Denso G3.5S injectors.

 

[Morbo]

My 2022 Yukon Denali Duramax is in the shop now for a new injector for cylinder 5. It went out with about 25,000 miles on the odometer and did the same thing your's did with all the bells and whistles going off. Will post details when I have the paperwork on all of the work they performed.

Got my Yukon back today. It was not the injector that failed, but was the wiring harness that was the cause. Specifically the codes that were thrown were P0205 and P0300. The techs find bulletin 21-NA-149 that explained the wiring harness could be compromised if routed incorrectly (I'm paraphrasing my service order, not the bulletin). They found the wiring harness was "stretched and pinched" on the alternator bracket. They repositioned the harness, checked the connections and said it was good to go.

Runs fine now, but we will see.

 

[Geotrash]

Got my Yukon back today. It was not the injector that failed, but was the wiring harness that was the cause. Specifically the codes that were thrown were P0205 and P0300. The techs find bulletin 21-NA-149 that explained the wiring harness could be compromised if routed incorrectly (I'm paraphrasing my service order, not the bulletin). They found the wiring harness was "stretched and pinched" on the alternator bracket. They repositioned the harness, checked the connections and said it was good to go.

Runs fine now, but we will see.

Thanks for following up. Fingers crossed!

 

[steiny93]

They found the wiring harness was "stretched and pinched" on the alternator bracket. They repositioned the harness, checked the connections and said it was good to go.

So a quality of build issue, unfortunate

 

[Morbo]

The "repair" did not last one month (see posts 8 & 13). On Friday January 12, the dashboard did its bells and whistles thing and the engine began running rough. Took it in to the dealer today and a quick scan says bad injector. Hmmm, that was the initial diagnosis last time, but then they determined it was really the harness.

They have the Yukon now, but I'm not optimistic about their ability to find or fix the problem. Will update when I get it back.

 

[Morbo]

Got my Yukon back today, injector #5 was bad. That was the original diagnosis in November, but then they changed their minds and said it was the harness.

They replaced:
PART NUMBER
==============
injector 55506244
pipe 55514860
harness 40009103
gasket 55497083
seal 55496593
coolant 12346290

Ran perfectly on the drive home from the dealer. Will report back if any additional problems.

 

[steiny93]

I suppose it's possible that both the harness AND the injector have failed, at different times but on the same cylinder.