2022 3500HD Service 4WD and Parking Brake setting when shifting to park

[nocturnalmotors]

Hello all,

 

Hoping to get some insight into an issue I encountered yesterday running errands at lunch. -10F, snowing, slush and ice on the roads. 19k miles on the truck; 2nd winter. Driving in Auto 4x4, all the sudden Service 4x4 comes up on info display and the Auto indicator turned orange. Cannot change 4x4 modes; buttons inop. Truck only has 2wd now... Also noticed the Parking brake sets itself every time I shift into Park. It'll come off when shifting into drive and tapping on the accelerator pedal.

 

At the dealer now but wanted to see if this is an issue anyone has encountered? I see some chatter on the 1/2 tons but limited info on the HD's...

 

Thanks in advance.

Edited December 22, 2022 by nocturnalmotors

[Pryme]

There is already a pretty long thread about this exact issue. It was recently posted in with codes I thought. 
 

edit. 
 

 

Edited December 22, 2022 by Pryme

[nocturnalmotors]

Yes, but almost a year ago and no resolution posted.

[Another JR]

https://www.tsbsearch.com/Chevrolet/PIE0604

[nocturnalmotors]

They ended up reflashing the TCCM and all is well so far...