Overdrive Control Switch
WARNING: This page is about a different car, the 2001 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The overdrive control switch may also be known as Transmission Control Switch (TCS).
The Overdrive Control (OD) switch is mounted on end of gearshift handle. Switch sends a signal to TCM. The TCM turns on indicator light and disables 4th gear. Malfunction of switch will cause lack of 4th gear (overdrive) disable function. To diagnose inoperative TCS, see SYMPTOM TESTS .