Transmission Control Switch
WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
The transmission control switch (TCS) (Fig 1) and (Fig 2) signals the PCM with key power whenever the TCS is pressed. On vehicles with this feature, the transmission control indicator lamp (TCIL) lights when the TCS is cycled to disengage overdrive. The operator of the vehicle controls the position of the TCS.