One problem related to check engine light on has been reported for the 2011 GMC Sierra. The most recently reported issues are listed below.
While driving down the interstate at 70 mph my service traction control message, service stabilitrak message, check engine light, and reduced engine power message came on. The vehicle started running very rough it would not go above 50 mph. I drove approximately 3 miles to get off the interstate into the gas station parking lot. I turned it off for about 10 minutes when I turned it back on only the check engine light was on I took it to the shop and they ran tests and said it was the battery. Two weeks later it happened again same thing when I turned it off it worked fine after sitting for 10 minutes I got home and when I got a chance to look at it to days later the check engine light was off. I have read a lot and forums about people having the same issue but no resolution truly being found. This is a 2011 GMC Sierra 1500 with the all-terrain package and only has about 60,000 miles on it it gets oil changes regularly. This really makes me think this is something gm should look into.