"transmission hot idle engine" message alert setting

[Rygrego]

Thanks Rygrego, and all,
ODB code came back with a failed transmission fluid cooler thermostatic valve.
One valve ($131) and three seals ($10) fixed my issue
& yes I replaced the fluid, filter and pan.

Display now reads between 149 - 182 for Transmission Fluid temp

Thanks for the help on this - you all are great!

Fantastic!

 

[Bagherra]

GM Valve (Part# - 85585333)
GM Seal (Part# - 85628205)
GM Seal (Part# - 23277649) Needed 2

Thanx!!

 

[ComputernerdBD]

I second the cooler and bypass kit OR the updated one for sure having been there myself unfortunately but not as lucky as you were.... Mishimoto MMTC-K2-14 cooler and Surecool STL010 bypass kit along with a B&M B&M 70392 pan are all on my 2018 Z71 Midnight Edition now with a rebuilt transmission. The first two of those I ordered on Christmas Day off Amazon sitting in a tow truck after blowing my original transmission hours from home on Christmas Eve, the pan I ordered from there in 2022. It was at 65K miles just hours after it being offloaded from the Auto Train in Northern VA on Christmas Eve and at the time I was driving thru Baltimore. The torque converter started shedding metal and was hesitating/slipping/flare shifting so felt something was up and checked the temp gauge. Temps started climbing 2F every few seconds up 240F so pulled off the road into a gas station. Fluid was just changed less than two months before with nothing there and had the new pan on there since the previous change year before that so I knew once I got it off the road and saw glitter on the dipstick it was done. Let it cool and drove to a hotel in low gear and had AAA tow it back to NY almost 300 miles away on Christmas Day back to a shop close to home I trust with all three of my trucks. Now I have had it back for almost a month since all of the repairs (which also included a new condenser and lines due to the glitter) and about 1400 miles later running nicely no warmer than 128-130F at high speeds and only gets up to 135F in town but that is in the winter with no towing and the aero shutters do influence it a bit so might consider investigating if those can be disabled. I am just about ready to put the truck back into service on longer range trips again now that I have somewhat regained trust as it seemed even doing fluid once a year and taking care of it was never enough given how poorly designed the thermal bypass valve seems was designed to let it get hot with almost no margins for the conditions most of us use our trucks for. Hope everything goes well for your vehicle and that you don't (knock on wood) face what I ran into.