2022 Silverado 2500HD Duramax Transmission Temp High with Normal Driving, Not Towing

gemarsh · September 8, 2022

That's not what I was hoping to read. gm failed by eliminating the tranny dipstick. Would be interesting to see if it's turning brown or stinks.

If you don't mind, keep this topic updated, please.

Jim 2022 · September 21, 2022

Hi there, I'm new to this forum and joined to see if anyone else was having similar issues that I am. I just purchased a 2022 GMC Sierra 2500HD Denali and immediately had problems with the transmission overheating and automatically downshifting to low gear. With only 200 miles on my truck and not towing, my truck starting down shifting into low gear while simply cruising around 35-45mph. The transmission oil warning light displayed and I could not get the truck to go into any other gear but low. I immediately pulled over and put the truck in Park and waited until the transmission cooled down. Even after the transmission had cooled, I could only get the transmission into something like Low 5 the remaining 3 miles to home. Only after shutting off the truck and letting it set for 5+ hours did it start shifting and running normal. I used the truck for another 1000 miles with no problems, until yesterday. The same thing happened again after a leisure drive and not towing. It started downshifting into low gear as if I were towing a load uphill? The transmission warning light did not come on but I had to put it in Park and wait for at least 30 minutes before it began shifting normal again. I noticed this morning that the transmission reached 219 while on just a short drive, which I'm not sure what the normal temperature should be? I'm hesitant to even consider towing a 5th wheel after these two experiences.

D Fowers · September 21, 2022

Sounds very similar to my experiences. I was told by my dealership to try towing, so 2 days ago I towed an 8,000lb trailer up the mountain and watched the transmission temperature climb. The last temp I saw was 257 and then the display showed "Transmission Hot, Idle Engine". I was close to home and made it there. I turned the truck off and then back on to see if I could see the temperature. It flashed quickly before going back to the warning screen. I was in the 260's. I have an appointment with the dealership to drop it off again (4th time) tomorrow to see if they can figure it out. No codes ever come up and the dealership says they can't try things to fix it cause they don't have a code or diagnosis and won't get reimbursed by GM for the work that they do. At one time they told be to drive it till something breaks so they will have a diagnosis and something to fix. I shouldn't have to break my brand new truck to have it fixed, it should be their responsibility to fix it. And, the thing that would break would be the transmission and then what, would they rebuild it for me or give me a new transmission? The dealership said it would be up to GM. I didn't pay this much money for a new truck that has a rebuilt transmission.

gemarsh · September 21, 2022

On 9/21/2022 at 11:24 AM, Jim 2022 said:

Edited September 22, 2022 by gemarsh
Must've been drunk. My response didn't have anything to do with post.

newdude · September 21, 2022

On 9/7/2022 at 10:15 AM, D Fowers said:

Update: The dealership installed the new Transmission fluid temperature sensor on Friday, September 2nd. I drove the truck and within about 30-40 miles the temperature was up to 252 degrees. I was not towing or driving aggressively. Obviously the sensor was not the problem. Not sure what the next step is in trying to figure this out.

4 hours ago, Jim 2022 said:

Hi there, I'm new to this forum and joined to see if anyone else was having similar issues that I am. I just purchased a 2022 GMC Sierra 2500HD Denali and immediately had problems with the transmission overheating and automatically downshifting to low gear. With only 200 miles on my truck and not towing, my truck starting down shifting into low gear while simply cruising around 35-45mph. The transmission oil warning light displayed and I could not get the truck to go into any other gear but low. I immediately pulled over and put the truck in Park and waited until the transmission cooled down. Even after the transmission had cooled, I could only get the transmission into something like Low 5 the remaining 3 miles to home. Only after shutting off the truck and letting it set for 5+ hours did it start shifting and running normal. I used the truck for another 1000 miles with no problems, until yesterday. The same thing happened again after a leisure drive and not towing. It started downshifting into low gear as if I were towing a load uphill? The transmission warning light did not come on but I had to put it in Park and wait for at least 30 minutes before it began shifting normal again. I noticed this morning that the transmission reached 219 while on just a short drive, which I'm not sure what the normal temperature should be? I'm hesitant to even consider towing a 5th wheel after these two experiences.

These both sound like a restricted cooler or a pump issue.

Dealer needs to try and flow test the trans cooler lines, and also check transmission pressure.

D Fowers · September 22, 2022

17 hours ago, newdude said:

These both sound like a restricted cooler or a pump issue.

Dealer needs to try and flow test the trans cooler lines, and also check transmission pressure.

I have wondered the same thing and thought they would have checked that but I will mention these things to them when I drop my truck off today. Thanks!

D Fowers · September 23, 2022

On 9/21/2022 at 10:24 AM, Jim 2022 said:

Hi there, I'm new to this forum and joined to see if anyone else was having similar issues that I am. I just purchased a 2022 GMC Sierra 2500HD Denali and immediately had problems with the transmission overheating and automatically downshifting to low gear. With only 200 miles on my truck and not towing, my truck starting down shifting into low gear while simply cruising around 35-45mph. The transmission oil warning light displayed and I could not get the truck to go into any other gear but low. I immediately pulled over and put the truck in Park and waited until the transmission cooled down. Even after the transmission had cooled, I could only get the transmission into something like Low 5 the remaining 3 miles to home. Only after shutting off the truck and letting it set for 5+ hours did it start shifting and running normal. I used the truck for another 1000 miles with no problems, until yesterday. The same thing happened again after a leisure drive and not towing. It started downshifting into low gear as if I were towing a load uphill? The transmission warning light did not come on but I had to put it in Park and wait for at least 30 minutes before it began shifting normal again. I noticed this morning that the transmission reached 219 while on just a short drive, which I'm not sure what the normal temperature should be? I'm hesitant to even consider towing a 5th wheel after these two experiences.

We hopefully have a solution. I dropped my truck off yesterday at the dealership and just got a call saying that they found a bulletin that was put out by GM concerning this issue. Apparently they have had several reported cases of the transmission overheating and have finally decided it is a valve housing in the transmission that is not opening at the rate that it should when it reaches certain temperatures. The part is not available, so it is more waiting until they are able to get one in. The service manager said that it will take the better part of a day to replace because they have to get into the transmission to do it. I am really hoping this is the fix, this has been a frustrating two and a half months since buying my truck. I will update this once the valve has been replaced and we know if it works. Cross your fingers.

leon dwinga · September 26, 2022

I am so sorry for what you are going through. Unfortunately, my brand new 2022 3500HD dually is also overheating. The dealer told me that 275 degree transmission temperature was normal for break in. I'm thinking "yeah right, man." Fast forward, I used the truck to tow my business trailer and the thing overheated repeatedly towing less than half of it's rating. I'm irate. 2800 miles with a proper break in and I have to count my shifts to keep the thing under 255 degrees where it shuts me down. Complete joke for an $80k truck. I should have stayed with rams. I've had 5 HD rams since 2017 and they have never overheated.

When you call around to different dealers to get service and they try to make you go to an Allison authorized service center. The transmission isn't even a real allison. DON'T BUY A NEW GM OR CHEVY TRUCK. NIGHTMARE.

GMCustomerService · September 30, 2022

On 9/21/2022 at 12:24 PM, Jim 2022 said:

Hi there, I'm new to this forum and joined to see if anyone else was having similar issues that I am. I just purchased a 2022 GMC Sierra 2500HD Denali and immediately had problems with the transmission overheating and automatically downshifting to low gear. With only 200 miles on my truck and not towing, my truck starting down shifting into low gear while simply cruising around 35-45mph. The transmission oil warning light displayed and I could not get the truck to go into any other gear but low. I immediately pulled over and put the truck in Park and waited until the transmission cooled down. Even after the transmission had cooled, I could only get the transmission into something like Low 5 the remaining 3 miles to home. Only after shutting off the truck and letting it set for 5+ hours did it start shifting and running normal. I used the truck for another 1000 miles with no problems, until yesterday. The same thing happened again after a leisure drive and not towing. It started downshifting into low gear as if I were towing a load uphill? The transmission warning light did not come on but I had to put it in Park and wait for at least 30 minutes before it began shifting normal again. I noticed this morning that the transmission reached 219 while on just a short drive, which I'm not sure what the normal temperature should be? I'm hesitant to even consider towing a 5th wheel after these two experiences.

This is certainly not what we like to hear, Jim 2022. 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 your 2022 GMC Sierra 2500 HD. To do so, please send an email to [email protected] with ATTN: Jim 2022/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.

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Jim 2022 · October 5, 2022

On 9/30/2022 at 1:44 PM, GMCustomerService said:

This is certainly not what we like to hear, Jim 2022. 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 your 2022 GMC Sierra 2500 HD. To do so, please send an email to [email protected] with ATTN: Jim 2022/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.

Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com

Thank you. I just emailed you the information that you requested. I do have an appointment scheduled for October 13th to have the dealership look at my truck.

Jim 2022 · October 6, 2022

On 9/23/2022 at 5:04 PM, D Fowers said:

We hopefully have a solution. I dropped my truck off yesterday at the dealership and just got a call saying that they found a bulletin that was put out by GM concerning this issue. Apparently they have had several reported cases of the transmission overheating and have finally decided it is a valve housing in the transmission that is not opening at the rate that it should when it reaches certain temperatures. The part is not available, so it is more waiting until they are able to get one in. The service manager said that it will take the better part of a day to replace because they have to get into the transmission to do it. I am really hoping this is the fix, this has been a frustrating two and a half months since buying my truck. I will update this once the valve has been replaced and we know if it works. Cross your fingers.

Hi there. Do you by chance happen to know the GM Bulletin number or have a copy of it? I have an appointment at my GMC dealership on 10/13/22 and they are not aware of this issue or the bulletin. Thanks!

D Fowers · October 11, 2022

On 10/6/2022 at 9:36 AM, Jim 2022 said:

Hi there. Do you by chance happen to know the GM Bulletin number or have a copy of it? I have an appointment at my GMC dealership on 10/13/22 and they are not aware of this issue or the bulletin. Thanks!

Just heard back from the dealership this morning. The bulletin number is 22-na-182. The replacement part is still not available with no estimated arrival date. Still waiting.....

Edited October 11, 2022 by D Fowers
Forgot to update part arrival information.

Jim 2022 · October 11, 2022

16 minutes ago, D Fowers said:

Just heard back from the dealership this morning. The bulletin number is 22-na-182. The replacement part is still not available with no estimated arrival date. Still waiting.....

Thank you so much! I spoke to the service department and provided them with this bulletin number. They indicated that the bulletin states to check for a twisted cooler line and to untwist it, if it is found to be twisted? I have an appointment on Thursday so I'll provide an update later. Thanks again!

newdude · October 11, 2022

4 minutes ago, Jim 2022 said:

Thank you so much! I spoke to the service department and provided them with this bulletin number. They indicated that the bulletin states to check for a twisted cooler line and to untwist it, if it is found to be twisted? I have an appointment on Thursday so I'll provide an update later. Thanks again!

See below. If lines are fine, TBV is the suspect. 10 speeds the TBV is internal to the transmission and not a part of the line set like the 8 and 6 speeds.

On 9/26/2022 at 2:16 PM, leon dwinga said:

I am so sorry for what you are going through. Unfortunately, my brand new 2022 3500HD dually is also overheating. The dealer told me that 275 degree transmission temperature was normal for break in. I'm thinking "yeah right, man." Fast forward, I used the truck to tow my business trailer and the thing overheated repeatedly towing less than half of it's rating. I'm irate. 2800 miles with a proper break in and I have to count my shifts to keep the thing under 255 degrees where it shuts me down. Complete joke for an $80k truck. I should have stayed with rams. I've had 5 HD rams since 2017 and they have never overheated.

When you call around to different dealers to get service and they try to make you go to an Allison authorized service center. The transmission isn't even a real allison. DON'T BUY A NEW GM OR CHEVY TRUCK. NIGHTMARE.

All 3 OEMs use thermal valves on their transmissions now. This could happen to a Ram or a Ford. You don't need a service center either, any GM dealer can work on it as its a GM 10 speed co-developed and certified by Allison.

See bulletin below as you likely have an issue.

On 9/23/2022 at 5:04 PM, D Fowers said:

We hopefully have a solution. I dropped my truck off yesterday at the dealership and just got a call saying that they found a bulletin that was put out by GM concerning this issue. Apparently they have had several reported cases of the transmission overheating and have finally decided it is a valve housing in the transmission that is not opening at the rate that it should when it reaches certain temperatures. The part is not available, so it is more waiting until they are able to get one in. The service manager said that it will take the better part of a day to replace because they have to get into the transmission to do it. I am really hoping this is the fix, this has been a frustrating two and a half months since buying my truck. I will update this once the valve has been replaced and we know if it works. Cross your fingers.

#22-NA-182: Information on 6L80 6L90 8L90 10L80 10L90 10L000 Equipped Vehicles With A Harsh Shift, Shudder, Surge, Stall, Transmission Overheating and/or High Transmission Fluid Temperature - (Sep 6, 2022)

This bulletin replaces PIP5792E. Please discard PIP5792E.

All engines except L3B

Condition

Some customers may comment on one or more of the following before or after the transmission has been overhauled:

Harsh shifting

Shudder

Surging

Stalling

Transmission overheating

Some customers may also comment on above normal transmission fluid temperature.

Cause

This condition may be caused by a twisted cooler line on low mileage vehicles.

Note: A twisted cooler line may cause DTC P27EC to set in the TCM on ETRS transmissions. (RPO MHS MQC).

Inspect for a twisted cooler line, example shown in the graphic above.

In some cases, it may be necessary to remove the under body panels in order to clearly see the cooler lines.

If the cooler line is twisted, disconnect the cooler line from the transmission auxiliary cooler and untwist it, then reconnect the cooler line.

If the cooler line remains misshaped after untwisting, the cooler line should be replaced then check the transmission fluid level following SI. Add fluid if needed.

If no concerns are found with the rubber line being misshaped, check the transmission fluid level following SI. Add fluid if needed.

The Thermal Bypass Valve (TBV) may be the cause of the overheat if a cooler line is not twisted or misshaped. The TBV will open at the following temperatures for the models listed in this TSB. 6 Speed (6L80, 6L90) - 158F (70C) - TBV is external to the transmission 8 Speed (8L90) - 194F (90C) – TBV is external to the transmission 10 Speed (10L80, 10L90, 10L1000) – 143F (61C) – TBV is within the valve body on all listed applications expect those equipped with 3.0 (LM2) Diesel. On the LM2 Diesel the TBV is external to the transmission

Jim 2022 · November 1, 2022

Update: I dropped off my brand new 2022 GMC 2500HD Denali on 10/13/22 for the tech to determine why the transmission was overheating and going into 'limp' mode. It took about a week for them to diagnose the problem and said it is the valve body. Today is 11/1/2022 and my truck is still in the shop waiting on parts. No ETA on the parts as of yet. I will provide another update in a week or two. Stay tuned!