AT4X fuel injector issue

obrien19 · June 8, 2022

So to sum up my current situation. Purchased AT4X new May 7. Put 79 miles on the truck, and man was this thing amazing. Driving home, from visiting my parents, dashboard just starts to go nuts. CEL light, Check Traction control, Check Emissions, just flashing across the dash. Call my salesman, dealership is closed, make arrangements to drop truck off Monday morning. Everything I tell my salesman, he relays to the Service advisor, and the intial though is bad lifter. Tell my to baby the truck home. Get the truck home, get a call Sunday (the next day). Grandfather isn't doing well/on death bed. Have no other choice to drive the truck. Put 100 miles on the truck, and CEL light goes off. Text my service advisor, let him know light is off, requests that I bring it in anyway. CEL is misfire on cylinder 5. Drop truck off, dealership has it for 3 days. Dealership tries to replicate the issue, they can't get the truck back 5/11. Drive truck around, don't see any issues. 5/17 while wife is driving, truck does the same thing. Have her drive truck to dealer. Call my salesman and service advisor, and they take the truck right in. 5/18 talk to the dealer, they ask what symptoms the truck has, tell them everything, truck is stuttering anything past 2k RPM. Truck is in limp mode. Dealership indicates that it is again a misfire on cylinder 5. Service department has checked lifters/valves. No collapsed valves and no stuck lifters but they found that the injector for cylinder 5 is bad. Either not enough fuel pressure or to much. Dealer tells me parts are on back order, and they expect them in a week. Well truck has been at the dealership since 5/17. Was told, the injectors that were sent, aren't the correct part number. GM rep told dealer that they are going to pull a fuel rail and injector set off the assembly line, to get the truck back up and running. There is absolutely no ETA on these injectors. Everytime i've talked to the dealership lately it's the same line. "Still no info on the Injectors. It’s on every ones mind and conversation but still no parts." From all my digging, the part number for a 2021 Sierra 1500 with 6.2 is 12710481, and those show in stock, at multiple dealers in my area. The new part number for 2022 Sierra 1500 with 6.2 is 1942064. From all my searching, on google, this forum. For the life of me, I can't find any engine changes that were made with the 6.2. So which brings me to now. Why two completely different part numbers, for essentially the same engine, for the same part. I've contacted GM customer service, and they just tell me to wait on the dealer. So any suggestions would be welcomed. My patience with this well gone by now.

newdude · June 8, 2022

3 hours ago, obrien19 said:

So to sum up my current situation. Purchased AT4X new May 7. Put 79 miles on the truck, and man was this thing amazing. Driving home, from visiting my parents, dashboard just starts to go nuts. CEL light, Check Traction control, Check Emissions, just flashing across the dash. Call my salesman, dealership is closed, make arrangements to drop truck off Monday morning. Everything I tell my salesman, he relays to the Service advisor, and the intial though is bad lifter. Tell my to baby the truck home. Get the truck home, get a call Sunday (the next day). Grandfather isn't doing well/on death bed. Have no other choice to drive the truck. Put 100 miles on the truck, and CEL light goes off. Text my service advisor, let him know light is off, requests that I bring it in anyway. CEL is misfire on cylinder 5. Drop truck off, dealership has it for 3 days. Dealership tries to replicate the issue, they can't get the truck back 5/11. Drive truck around, don't see any issues. 5/17 while wife is driving, truck does the same thing. Have her drive truck to dealer. Call my salesman and service advisor, and they take the truck right in. 5/18 talk to the dealer, they ask what symptoms the truck has, tell them everything, truck is stuttering anything past 2k RPM. Truck is in limp mode. Dealership indicates that it is again a misfire on cylinder 5. Service department has checked lifters/valves. No collapsed valves and no stuck lifters but they found that the injector for cylinder 5 is bad. Either not enough fuel pressure or to much. Dealer tells me parts are on back order, and they expect them in a week. Well truck has been at the dealership since 5/17. Was told, the injectors that were sent, aren't the correct part number. GM rep told dealer that they are going to pull a fuel rail and injector set off the assembly line, to get the truck back up and running. There is absolutely no ETA on these injectors. Everytime i've talked to the dealership lately it's the same line. "Still no info on the Injectors. It’s on every ones mind and conversation but still no parts." From all my digging, the part number for a 2021 Sierra 1500 with 6.2 is 12710481, and those show in stock, at multiple dealers in my area. The new part number for 2022 Sierra 1500 with 6.2 is 1942064. From all my searching, on google, this forum. For the life of me, I can't find any engine changes that were made with the 6.2. So which brings me to now. Why two completely different part numbers, for essentially the same engine, for the same part. I've contacted GM customer service, and they just tell me to wait on the dealer. So any suggestions would be welcomed. My patience with this well gone by now.

Dealer is correct, no injectors available, they are on BO.

Both of the #s you posted aren't good for 2022 with the L87 6.2 either.

The injector for 2022 new and 2019-2022 LTD is different. They changed the connector ends.

19420648 is the original # for 2022.5, replaced by 12726901.

All you can hope for is that your dealer's parts mgr and service mgr have the case escalated as far as possible with SPAC and their DMA rep. Hopefully they can get an injector or do what GM calls and "up assembly" so a complete rail.

Edited June 8, 2022 by newdude

obrien19 · June 9, 2022

13 hours ago, newdude said:

Dealer is correct, no injectors available, they are on BO.

Both of the #s you posted aren't good for 2022 with the L87 6.2 either.

The injector for 2022 new and 2019-2022 LTD is different. They changed the connector ends.

19420648 is the original # for 2022.5, replaced by 12726901.

All you can hope for is that your dealer's parts mgr and service mgr have the case escalated as far as possible with SPAC and their DMA rep. Hopefully they can get an injector or do what GM calls and "up assembly" so a complete rail.

Thanks for the clarification that GM changed the connector for the fuel injector. As far as the part numbers I listed. I got those numbers directly from the GM/AC Delco part website by plugging in my VIN for my AT4X. The part number for the 21 Sierra, I used my buddys VIN. The part number you listed, directs me to a "Fuel Injector Kit", that shows in stock at GMPartsDirect. Do you work for GM?

newdude · June 9, 2022

41 minutes ago, obrien19 said:

Thanks for the clarification that GM changed the connector for the fuel injector. As far as the part numbers I listed. I got those numbers directly from the GM/AC Delco part website by plugging in my VIN for my AT4X. The part number for the 21 Sierra, I used my buddys VIN. The part number you listed, directs me to a "Fuel Injector Kit", that shows in stock at GMPartsDirect. Do you work for GM?

Hard to trust the online GM parts sellers. They may "say" they have it, but they don't and have to order it.

It is listed as a "kit" yes, but it is one individual injector, so for example, you needed to replace all 8, you'd order 8 of that #.

I also doubled checked and VIN verified on a 6.2 that the #s I posted are correct. 19420648 is the original, replaced by 12726901.

As for your last question, not directly for but in a position where I can at least try to be of help if possible.

Edited June 9, 2022 by newdude

ssandefur · August 4, 2022

I have the same issue- bought a 2022 GMC Sierra 1500 AT4 on 6/11/2022. Truck wasn't running right, felt a stutter or shudder under light load. Have had a few instances of lights on dashboard going off. Took the truck to dealership on 6/20/2022 and diagnosed with a bad fuel injector on #6 cylinder. Ordered part on same day, backordered, and still waiting today 8/4/2022 and still no ETA on when the dealer will receive the part. On dealers advice I am still driving the truck but its so annoying I don't enjoy it. I have called dealerships all over the country looking for this part and found a few that have them however they were ordered for a customer, can't sell. I would love to know the reason for the backorder and a realistic time table for GM to get the parts out. Would appreciate any comments anyone has relative to this matter.

wachs · August 12, 2022

I might as well chime in. Same story as every else here. Mine acted up day after I got it home, May 16. Still waiting. Not sure what we can do except wait at this point. I have be assigned a "delayed parts specialist" at gm but it seams like smoke and mirrors to pacify the situation until injector comes in. Not getting anywhere with the gm team. Sad sad sad.

newdude · August 12, 2022

On 8/4/2022 at 12:15 PM, ssandefur said:

I have the same issue- bought a 2022 GMC Sierra 1500 AT4 on 6/11/2022. Truck wasn't running right, felt a stutter or shudder under light load. Have had a few instances of lights on dashboard going off. Took the truck to dealership on 6/20/2022 and diagnosed with a bad fuel injector on #6 cylinder. Ordered part on same day, backordered, and still waiting today 8/4/2022 and still no ETA on when the dealer will receive the part. On dealers advice I am still driving the truck but its so annoying I don't enjoy it. I have called dealerships all over the country looking for this part and found a few that have them however they were ordered for a customer, can't sell. I would love to know the reason for the backorder and a realistic time table for GM to get the parts out. Would appreciate any comments anyone has relative to this matter.

2 hours ago, wachs said:

I might as well chime in. Same story as every else here. Mine acted up day after I got it home, May 16. Still waiting. Not sure what we can do except wait at this point. I have be assigned a "delayed parts specialist" at gm but it seams like smoke and mirrors to pacify the situation until injector comes in. Not getting anywhere with the gm team. Sad sad sad.

Stills shows no inventory/no ETA for stock. Assuming both of you have a SPAC case on the injector at your respective dealerships, the parts counter would be able to see if GM has sent them any ETA progress.

wachs · August 16, 2022

Just to clarify which injector is correct for which year. It seems injectors for 19 and up are on back order or confusing at the very least. I have a 2022 LTD with the 6.2. My dealership received A fuel injector within a week, Unfortunately when they started the repair it was found that it was the wrong one for my truck. I find this strange as I would guess that they ordered it by VIN#. My question is they said I need part # 12726901. Could it be a case of the left hand doesnt know what the right is doing? Being a 22 ltd with very late build date could it have the "refresh 22" injector harness and injectors? After three months of waiting im tempted to go look at my truck for myself, if its even possible to see at all?

S.R. F · September 2, 2022

I'm having the same issue with my 2022 Yukon XL Denali with 6.2L engine. Is this the same injector? Truck has been at dealer for over a week. Any advice on what I can do?

Edited September 2, 2022 by S.R. F

newdude · September 2, 2022

2 hours ago, S.R. F said:

I'm having the same issue with my 2022 Yukon XL Denali with 6.2L engine. Is this the same injector? Truck has been at dealer for over a week. Any advice on what I can do?

Quite possibly the same injector. Make sure they have a SPAC case on it, then hope and pray they can get their hands on one.

Edited September 2, 2022 by newdude

newdude · September 2, 2022

On 8/15/2022 at 8:08 PM, wachs said:

Just to clarify which injector is correct for which year. It seems injectors for 19 and up are on back order or confusing at the very least. I have a 2022 LTD with the 6.2. My dealership received A fuel injector within a week, Unfortunately when they started the repair it was found that it was the wrong one for my truck. I find this strange as I would guess that they ordered it by VIN#. My question is they said I need part # 12726901. Could it be a case of the left hand doesnt know what the right is doing? Being a 22 ltd with very late build date could it have the "refresh 22" injector harness and injectors? After three months of waiting im tempted to go look at my truck for myself, if its even possible to see at all?

LTD trucks have 2 different p/ns to choose from based on the J21 RPO code. The 12726901 appears to be a refresh truck injector. Your dealer should have pulled the # off the old injector to verify which one was needed.

Edited September 2, 2022 by newdude

SR F · September 6, 2022

Any update from anyone on getting their fuel injectors? My 2022 Yukon XL with 6.2 has now been at the dealer for two weeks. Exact same symptoms noted above by all. In my case it missfires on cylinder #2 so they say I need a new injector - GM Part #12726901 - also as noted above. It can't just be one injector.

Clay Caudill · September 7, 2022

2022 AT4 with 6.2 purchased in July. I have had it in 3 times, duplicated issues in drive the stutter and shudder under light load. Said there is nothing wrong and its normal driving conditions. If a new vehicle drives like that, it's TRASH! I have found several issues with shavings in transmission, fuel injector issues, and programming issues. Seems like they just tried to crap out all these parts to produce trucks and didnt quality test them. Im getting super annoyed. I havent had any lights come on though.

Clay Caudill · September 20, 2022

Not sure if this will help anyone out with the 10 speed transmission. The shudder,surge, etc.... in my 22 at4 with the 6.2, we have went through injectors, transmission fluid, torque converter, and just about everything else with no resolution. It is a software concern for the active fuel management system (im sure there is a more technical term). If you put your vehicle in manual and shift to 9th gear and leave it, it bypasses the AFMS and the shuddering goes away. I just ledt the dealership and entire ride home was smooth as can be. Hopefully this helps out

Combat1130 · October 5, 2022

My 2022 AT4 same issue. Cylinder #6. No stock, no availability and no ETA. If a 12726901 is a replacement for the 19420648 is the only thing different the connector? Is the injector physically the same otherwise? Why can I not just change the connector, slap in a 19420648 and be on my way?