MIL Always On When Engine Is Running, No DTCs Are Present

Check MIL circuits. On Blackwood, Continental, Escape, Expedition, Focus, F150 Pickup, LS, Mustang, Navigator, Thunderbird, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other models, go to TEST NB, step 1)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article.