Transmission Control Switch (TCS)

The transmission control switch (TCS) sends a signal to the powertrain control module (PCM) when the driver selects the D4 position, canceling operation of 5th (overdrive) gear.

The TCS is located within the range selector assembly (base shifter only).

The PCM uses this signal to control the shift solenoids to disengage/disable 5th gear operation and activates coast clutch. At the same time, the PCM changes the instrument panel indicator to display D4.

When the driver moves the range selector lever back to the D5 position, 5th gear operation is enabled, the coast clutch is released and the instrument panel indicator changes to display D5.