4R100 applications only
WARNING: This page is about a different car, the 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, 2004 Ford Excursion, and 2004 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Pushing the TCS will either disengage or engage the overdrive function of the transmission. If the OVERDRIVE is disengaged, the word OFF will illuminate on the transmission control selector lever.