Try it without the Snap-on scanner, sometimes it gives you hassles. Just push the button down on X11/4 for three seconds and release. Count blinks and repeat three second hold, until same code comes up again, that is if there's more than one. Then push and hold button for eight seconds and release to clear code. Repeat if more than one code stored. If there is no red light when you push the button you'll need to trace voltage. Good luck.