Transmission Control Switch

Transmission Control Switch (TCS) is a momentary contact switch that allows driver to cancel operation of 5th gear (Overdrive). TCS is located on gearshift lever handle. When driver presses TCS, a signal is sent to PCM. PCM uses shift solenoids to disengage or disable 5th gear operation and activate coast clutch. PCM also illuminates TCIL to notify driver that 5th gear is canceled. When TCS is pressed again, 5th gear operation is enabled, coast clutch is released and TCIL is turned off. When ignition switch is cycled (vehicle shut off and then started again), TCS is turned off and 5th gear will be enabled.