Transmission Mode Switch: Description and Operation

Transmission Control Switch (TCS)
The transmission control switch (TCS) is included with floor-mounted shifter and available on column shifter and is not included on models with 3.0L (2V) engine.

The transmission control switch (TCS) is a momentary contact switch located on the floor shift console, next to the transmission range selector lever. When the switch is pressed, a signal is sent to the Powertrain Control Module (PCM) to allow automatic shifts from first through fourth gears or first through third gears only, locking out fourth gear (OVERDRIVE). The powertrain control module then energizes the transmission control indicator lamp on the instrument cluster to indicate OVERDRIVE OFF.