I have the same truck and programmer, the SES will come on untill you have driven in each postion on your programmer, then it will go out. I have mine set on 3 and get about 18-19 mpg all of the time. Took trip from So Cal to Idaho and got 21.9 mpg average. Yes I did the real math not just the lie-o-meter. I only use th 5 extreme postion when I want to smoke somebody.