"Reduced Acceleration, Drive with Care" message for Valve Body malfunction

[sigmonster]

2024 2500 gasser with 47,000 miles.  Driving on interstate Friday when my truck shudders, downshifts, and I get the above message with check engine light.  Transmission would not upshift.  I had to drive home 2 hours at 65 mph at 3600 RPM with transmission temps 190-200 degrees.

 

Got it to the dealer Monday.  They ran the code and said the #1 valve body was malfunctioning in the transmission.  Miraculously, they had the part in stock and I had a new valve body installed that day with new transmission fluid/filter.  Thankfully, all under warranty.  Shout out to Everett Chevrolet in Hickory, NC.