I have 55,000 miles on my truck,not long ago I did a trans valve body upgrade, I ran a tuner for about two months I did not drive every day and I don't feel as tough I ran it hard, I have not had the tuner on for a good while and probably wont use as I don't want any problems, but I was going out of town to see my sick parents and the check engine light came on, I have a edge gauge and this is the code it showed 700

P0700-Means that there is a code set in the TCM. You need a reader that will read TCM codes to find out what the code is.

I wanted to make sure my stock tune was on so I put my tuner to stock,the ruck from what I remeber was alreadystock but I wanted to be sure and now the check engine light is gone