D Fowers

UPDATE.....I picked up my truck yesterday afternoon after having the transmission valve body replaced and it looks like that did the trick. The transmission temp got as high as 142 yesterday and even went down to 138 at one point. I am excited, I feel like I finally have the new truck I ordered after having it for 4 months. I hope this is the fix for the others on here having similar issues. If anything changes I will post another update.

Update: I just got off of the phone with the dealership and they have received the valve body for my truck. I will be dropping it off in the morning to have it installed. I will update once I have had a chance to drive it and see if fixes the transmission temperature issue. This has been a long frustrating 4 months, let's hope this is the fix!

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.....

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.

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!

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.

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.

While I was starting to read your post I got a call from the dealership. The service manager said when he went to speak to the parts manager that they had miraculously received a FedEx package last night with the part and they hadn't had time to process it in yet. I can take my truck in tomorrow to have it installed. What horrible communication between the dealership and GM. Two days ago they told me it would be Oct/Nov before they could get it in. Something is screwy in their system. I'm crossing my fingers that this is the fix for my issues. They didn't sound 100% sure.

Well, this is very interesting, thank you for sharing this. I got on Rockauto's website and put it in my cart and it said that I could have it by Sept. 12th. I called the dealership service manager that I've been working with. He verified the part number with me and it was correct. He said he is not authorized to shop 3rd party parts companies and relies on GM for parts. I asked if I could order it and bring it in and he said he would not be authorized to put it in unless it comes from GM. He is going to have his parts manager research and find out why GM is releasing parts to 3rd party companies over dealerships and it that is the case he said they would be very upset. So, I am waiting to hear back on what they find out. Thanks again for sharing this information with me.

It is coming up on 2 months now that I have had my new truck and I am still having the same issues. The dealership said they believe it is a bad sensor which is on back order with no estimated delivery date. It has been three to four weeks ago that they said that. Meanwhile, I cannot use the truck for the purposes I purchased it for. I can't tow with it or it will go into limp mode and I will be stuck somewhere. My frustration is that GM puts out thousands of trucks per week with these sensors and I can't get one shipped to me to fix my truck. I have contacted GM directly which has not helped getting the sensor here any faster. I am very frustrated.

Thank you, I will send in the information.

About what temp is it typically at?

Picked up my brand new truck on 7/9/22 with 8 miles on it. Drove it that day, normal conservative driving on pretty flat roads. Outside temperature that day was around 100 degrees. At about 30 miles on the odometer, the clutch fan kicks in which was pretty loud. Engine temp was at 210, no problem. At that time I didn't know how to pull up the transmission temp so I don't know what it was. I drove straight home and when backing into the garage I hear the dash dinging and I see "Transmission Hot Idle Engine" warning which I found out will appear if the Trans temp reaches 260 for 5 seconds or more. Took it in, they couldn't replicate the issue or find any problems. The next weekend I had about 120 mile trip (not towing) with mostly flat driving and the trans temp reached 232. My brother in his 2020 Silverado 2500HD Duramax was double towing (5th wheel and Razor) up large hills got up to 160-175 degrees. I'm frustrated and hesitant to tow anything with the way my truck is acting. The service department acts puzzled and not sure what to do. It is actually there right now being looked at. Wondered if anyone else has experienced these kind of issues or has any ideas.