does engine have sensor shut off

It has an inertia switch that shuts fuel off if crashed...or sometimes just bumping something, or hitting a pot-hole hard..does not take much. It a red button, they are in different places on Expeditions, but usually behind passenger side kick-panel. Pull carpet back, if not there try looking all around drivers side kick-panel-- behind it, up under dash

http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/98exdog1e.pdf Page 128 shows an image, would not let me copy. Look right beside glove box on side

The safety cutoff is on the lower right hand side panel, in front of the door post and just above the passenger right foot and below the glove box.