ZR2 Randomly going into "limp" mode

[smoky]

On 3 separate occasions, my 2023 1500 6.2L ZR2 has made a "shudder", as if driving over a rumble strip or railroad tracks and immediately goes into decreased acceleration mode. It throws a check engine light and flashes "service transmission" and "service traction control". On the first two occasions, I was able to immediately take it to a close by dealership (not where I purchased it), and both times the system was full of random codes. The first time, it was shortly after the recall test, and the dealership blamed it on the other dealership not clearing the codes from the test. The second time, I was in another state, and the dealership cleared the codes and offered no explanation for why it did it other than saying "the information system of the truck is briefly losing contact with the power train". The third occasion happened while using cruise control on the interstate. It canceled the adaptive cruise control while going 75 mph, then a minute or two later, the truck shuddered and went into decelerated mode. I pulled over killed the truck for 30 seconds or so, then it cranked and ran as normal. The engine light stayed on for the rest of the drive then cleared itself later that afternoon.

I've driven it since then for an additional 500 miles or so over the course of a week with no issues. I have it at a dealership now and they have all the random codes but can't seem to figure anything out.

I can't be the only one with a 6.2 that has experienced this. Any thoughts?

Much Appreciated!!

 

[AXE]

You've likely gotten a bad transmission valve body. These new transmissions have well-documented cases of the valve body orifice plugging up and causing issues. Your dealer can do a proper diagnosis and hopefully warranty. I keep hearing there will be a full on recall, but they haven't gotten that done.

 

[smoky]

Thanks! Any chance my pedal commander could be causing issues? It's been on the truck since about 5,000 miles (now at 62,000) and has never seemed to cause an issue, but I've read some other threads on here that made me at least question it.

 

[AXE]

Thanks! Any chance my pedal commander could be causing issues? It's been on the truck since about 5,000 miles (now at 62,000) and has never seemed to cause an issue, but I've read some other threads on here that made me at least question it.

I dont use one, but you could unplug it to eliminate that issue. My gut says valve body issue.

Have you serviced the transmission and filter yet?

 

[ZR2xBIZON]

I recommend a BlueChew

 

[smoky]

I dont use one, but could unplug iy to eliminate that issue. My gut says valve body issue.

Have you serviced the transmission and filter yet?

Yes, transmission was serviced at 45,000 miles.

 

[smoky]

I recommend a BlueChew

That would be a "hard" pill to swallow, but I'd consider it if it would "straighten" it out!!

 

[ZR2xBIZON]

That would be a "hard" pill to swallow, but I'd consider it if it would "straighten" it out!!

Glad we were able to resolve the challenge.

Use promo code ZR2xBIZON on your next purchase for a free side of napkins

 

[GatorZR2]

On 3 separate occasions, my 2023 1500 6.2L ZR2 has made a "shudder", as if driving over a rumble strip or railroad tracks and immediately goes into decreased acceleration mode. It throws a check engine light and flashes "service transmission" and "service traction control". On the first two occasions, I was able to immediately take it to a close by dealership (not where I purchased it), and both times the system was full of random codes. The first time, it was shortly after the recall test, and the dealership blamed it on the other dealership not clearing the codes from the test. The second time, I was in another state, and the dealership cleared the codes and offered no explanation for why it did it other than saying "the information system of the truck is briefly losing contact with the power train". The third occasion happened while using cruise control on the interstate. It canceled the adaptive cruise control while going 75 mph, then a minute or two later, the truck shuddered and went into decelerated mode. I pulled over killed the truck for 30 seconds or so, then it cranked and ran as normal. The engine light stayed on for the rest of the drive then cleared itself later that afternoon.

I've driven it since then for an additional 500 miles or so over the course of a week with no issues. I have it at a dealership now and they have all the random codes but can't seem to figure anything out.

I can't be the only one with a 6.2 that has experienced this. Any thoughts?

Much Appreciated!!

GM Issues New Valve-Body Repair for P0747 on 10-Speed (10L80/10L90)

GM has issued TSB #25-NA-255 for 2021–2024 trucks and SUVs with the 10-speed. Instead of replacing the valve body for P0747, the fix now calls for a new feed-limit valve, spring, and spacer plate—marking a major shift in how dealers handle this common transmission failure.

www.duramaxnews.com

GM Confirms Gen-3 10-Speed Valve Body: What Changed vs. Gen-2 (10L60/80/90) Service Bulletin # 25-NA-334

GM released a Gen-3 service valve body for 10L60/80/90. It improves robustness and sediment control, removes the auxiliary body, relocates key solenoids, simplifies harnessing and flow, deletes the internal TBV lineup on certain RPOs, and includes a revised bolt kit. First field units appeared...

www.duramaxnews.com

Here's all the lasted service bulletins on the transmission valve body. I would unplug the pedal commander as @AXE said see if anything changes. The way the pedal commander operates could be throwing the ecm off if the module itself has an issue.