TCIL Always On When Engine Is Running, No DTCs Are Present
WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2003 Mercury Sable, 2003 Mercury Mountaineer, 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Check TCIL circuits. On Aviator, Expedition, Focus, LS, Mustang, Navigator, Thunderbird, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other models, go to TEST TB: TRANSMISSION CONTROL SWITCH/TRANSMISSION CONTROL INDICATOR LAMP , step 6) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.