My CE light was on when I picked up my new truck at the dealer! I had to leave it and pick it up the next day instead.
Also mine came on one time this summer. Truck was still running OK but the ECO light didn't come on although MDS was still working. I was away camping so I planned to ignore it till I got back home. After a couple of days it went off by itself.
I called the dealer when I got home and he said if it's off now everything is good.
It hasn't come on since.