Transmission Control Switch

Transmission Control Switch (TCS) sends a signal to PCM when driver selects "D4" position, canceling operation of 5th (overdrive) gear. TCS is located in selector lever assembly (base shifter only). PCM uses this signal to control shift solenoids to disengage 5th gear operation and activates coast clutch. PCM changes instrument panel indicator to display "D4". When driver moves selector lever back to "D5" position, 5th gear operation is enabled, coast clutch is released and instrument panel indicator changes to display "D5".