2024 GMC Denali Ultimate Duramax 10 speed with shudder

JCraven · July 9, 2023

A little history first. I had some warning lights come on at about 800 miles for various items but I recall the collision system light and traction control being 2 of them (no I haven't wrecked the truck) and the display said Reduced Acceleration. The dealership flashed the ECM and said this would take care of the issue. The lights are out but just prior I had noticed this light shudder/jerk to the transmission when lightly accelerating or coasting at lower speeds. The shudder/jerk has not gone away since the ECM flash. This puts me in mind of a shift shock issue but it has me wondering if it could be a brake issue (grabbing) considering the lights from the ECM issue. The code triggered by the system was a P060C which aligns with the ECM flash so maybe these aren't related but curious if anyone else has heard of this issue. Added bonus...My A/C didn't seem very cold so I asked them to look at it during this time and they found a hole in the evaporator coil. My first GM product in over 30 years and all of this in the first 1200 miles so I'm not feeling like I made a smart purchase. Oh and I'll add to it that my local dealership can't provide me with a loaner vehicle and this is my only vehicle so now I get to miss a day of work.

MTU Alum · July 10, 2023

There is some new software that should be available at dealerships to address the P060C issue.

The P060C has about 100 different reasons to set so we would need to see some of the other codes to determine if this software change fixes your issue.

#iworkforGM

GMCustomerService · July 14, 2023

On 7/9/2023 at 8:59 AM, JCraven said:

A little history first. I had some warning lights come on at about 800 miles for various items but I recall the collision system light and traction control being 2 of them (no I haven't wrecked the truck) and the display said Reduced Acceleration. The dealership flashed the ECM and said this would take care of the issue. The lights are out but just prior I had noticed this light shudder/jerk to the transmission when lightly accelerating or coasting at lower speeds. The shudder/jerk has not gone away since the ECM flash. This puts me in mind of a shift shock issue but it has me wondering if it could be a brake issue (grabbing) considering the lights from the ECM issue. The code triggered by the system was a P060C which aligns with the ECM flash so maybe these aren't related but curious if anyone else has heard of this issue. Added bonus...My A/C didn't seem very cold so I asked them to look at it during this time and they found a hole in the evaporator coil. My first GM product in over 30 years and all of this in the first 1200 miles so I'm not feeling like I made a smart purchase. Oh and I'll add to it that my local dealership can't provide me with a loaner vehicle and this is my only vehicle so now I get to miss a day of work.

This is certainly not what we like to hear, JCraven. Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with the transmission on your truck. To do so, please send an email to [email protected] with ATTN: JCraven/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s Privacy Policy, please visit https://www.gm.com/privacy-statement.html. The information you provide may be monitored and recorded and is subject to the GM Privacy Statement.

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zeb321 · July 15, 2023

I had this same issue happen to me this week. 2024 Sierra 2500HD with only 170 miles on it when it happened. I was just driving along when I received a Service ESC message followed by a Reduced Acceleration warning on the center display. I also had the forward collision, traction control and check engine lights come on. I also noticed the shudder/jerk that the OP mentioned, but I only had it when coasting to a stop.

After parking my truck for a few minutes, I started it again and all the warning lights and messages were gone except for the check engine light. I took the truck for a short drive and it seemed to be back to normal.

The only code that was present was P060C. According to the myGMC app, my truck is up to date with the N23-240810 update installed on 6/2/23.

TarHeelTerrier8 · July 29, 2023

Any updates from those who have had this issue? We bought a 2024 2500HD Z71 with the Duramax about one month ago. Today, just over 1400 miles, I was coasting up to a traffic light when I felt a sudden jolt. Immediately had a check engine light, indicator that collision detection was no longer working, check ESC message, check traction control message and reduced acceleration message. I ran the code reader and got the same PO60C code. I find several mentions of this happening in the gasoline versions related to either faulty wiring or lifters. However I don’t see nearly as many for the Duramax.

Did the ECM update seem to fix this issue for you guys? Or have you had recurrent issues? Appreciate any information you can provide.

zeb321 · July 29, 2023

Sorry for the delayed update, I was away on vacation.

I took my truck to the dealer a little over a week ago. They said there was a service bulletin for this issue and updated my PCM. My invoice states the following:

C2A07 ECM indicated torque signal malfunction. Bulletin PIP593 for DTC. Update PCM with latest calibration O5YY175967812.

Everything seems fine with the truck again, but I have only put about a 100 miles on since the PCM update.

TarHeelTerrier8 · August 1, 2023

Thank you for the update. Taking ours into the service center today.

JCraven · February 10

Update on my issue...

The problem turned out to be the high pressure fuel rail. Replaced and issue corrected. While there I pointed out that my heated seats didn't light up when selected and was curious if I was missing a component or what was happening. They found the control unit was bad for the heating controls. I had to wait several months for the replacement but that has been corrected as well. While performing that work I asked them to check the truck for leaks as I was seeing an oil spot in my driveway. They found a bad front seal in my transfer case. Not a huge deal as the part was easy for them to get but it apparently requires a special tool which they are having no luck in getting from GM. I've owned several vehicles over the years and had some minor issues but this GMC is pitiful given the price tag and it being brand new. Now at 15k miles and have not owned the truck for a period of time that there was no issue.

Edited February 10 by JCraven