The 1693 code is a companion code that comes up when another code is present. I got it when I installed smarty & was told to run the truck & it should clear itself. It cleared out & never came back. I heard that it is common when using tuners to install new software [switching programs]. I tried out a loaner smarty from a friend & set back to stock... later installed another smarty from Bob Wagner & code came up. I was told that the computer got confused because it has seen this program before, but had to learn it again. I'm not sure what the guy meant by this, but that is what I was told.