I have a 22.5 LTZ with the LM2 and hit the brakes hard the other day ( deer ran out in front of me) and it looked like DEFCON 5 on the dash! Service emission system-90 miles until speed restricted to 65mph...ect... I had to drive it the next day and all of that on the dash disappeared and by the next day check engine light was off and everything was normal? Still taking it to the dealer.....I have a whole 190 miles on my 3.0 and a check engine light came on and the screen states: Service Emission System - See owners manual. Then flashes "In 175 miles speed will be limited to 65 mph.
Nothing in the owners manual and what they gave me as a manual is a booklet that states on the outside "Silverado 1500 Essential Operating and Safety Information". No "owners manual"
Looked up the 3.0 duramax manual on line and couldn't find anything there.
Any help would be appreciated.