BeWitty

So my truck drove well since my last post. After my post on 6/26 I drove it to the dealer and the removed the 2 primary connections that were shorted. Not sure why they didnt do this after installing the secondary connectors that bypassed the primary? But it drove well until yesterday and got the P1098 (cooling fan running full blast) and P1498. Back to the dealer.... Not sure if this is completely unrelated or not. I did occasionally get the P1098 code amongst many others while dealing with me previous issues.

Well it happened again.... As stated above, I dropped my truck off at the service dept. last Saturday, June 15th. I got a call Monday, June 24th that they repaired two wires that had shorts and updated the TCM. It drove great Yesterday and then today on my way to work it had the same hard shift, followed by every dash light coming on, and reduced power mode. Had to restart the truck 3 times to get the reduced power mode to clear and continue driving into work. Same codes P0700, P2826, 2824, and P1098. I am over this! Every time it is 'repaired' it lasts 2 days! So this will be my 7th trip back to the dealership, 4th for the exact same issue. When will GM offer a buy back on the $60K truck?

Before today the codes have always been P0700, P2826, and P2824. (9 times - 8 before new valve body, 1 after new VB) Todays episode was different. I had multiple bad shifts and the check light didn't come on. About a minute after it slammed hard and I had multiple dash notification (service esc, reduced power, traction control off, service parking brake). I turned the truck off and waited a few minutes like I always do and restarted it and drove to work. I checked the codes when I got to work. Same 3 but I also got P1098 for the first time. Not sure what was different about this episode. I am scheduled to drop my truck off at the dealership on Monday. I wont be driving this truck to work anymore this week, cant trust it. I believe there is a big issue with the transmission itself and it is causing the solenoids (valve body) to malfunction causing those to throw the codes? But the real problem is the tranny. I'm worried they are just going to replace the valve body again and i'll be doing this same thing in a month.

I have a 2021 Sierra AT4 with the 10sp and 3.0l. It has 44K miles. Trans issues started end of April. After 8 CEL episodes with hard shifts/stutters and a couple episodes with multiple dash lights and reduced power mode I started a spread sheet that showed it was always 15 miles into a drive, 155* tranny temp, and going 48-52 MPH. Finally the dealer was able to diagnose it and determined it to be a bad valve body. I was told 6 mo back order but they got it in after 3 weeks. I picked it up saturday (3 days ago) and the exact same thing happened again today. Very upset to say the least..... Whats the next step? I have also had a few exhaust sensors fail.