Transmission Control Switch (TCS)

The TCS is a momentary contact switch that sends a signal to the PCM when the driver selects the D4 position, canceling operation of fifth (overdrive) gear.

The TCS is located within the range selector assembly.

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

When the driver moves the selector lever back to the D5 position, fifth gear operation is enabled, the coast clutch is released and the instrument panel indicator displays D5.