Transmission Pressure solenoid??

[2016HD]

Only 26000km on my 16 HD. 6.0l Gas. 6l90e.  Just out today in the snow in town and check engine light came on. Took to dealer they scanned it. Codes P0777 P0776 and 1 other i missed. Booked for service on Monday? This seems very premature and strange to me? Easy driving. Low amount of towing etc. No symptons prior to that i could tell? 

Anyone with symiliar issues or repairs? 

First new truck and i normally do my own repairs. Tranny rebuilds included.  Could this be the Torque converter issue? This early?  Thanks for any help guys

[2016HD]

No one has had any issues with the 6l90 transmissions?