Will not engage into gear on 2012 Chevrolet Silverado 2500 HD

I own a 2012 Chev Silverado HD Diesel, with 23000km. In going to drive it, I found that it would turn over/start, but when trying to engage into any gear it would not do so. The gear selector moved without issue, indicators worked in moving between 4high and 4low, back to 2wd but could not feel transmission engage. The rear view camera would not turn on either when placed in reverse. Vehicle towed to Dealership and a week later they are still on phone with the GM Engr trying to figure out the problem.

1 answer
poss warranty issue return to dealer