Overdrive Switch: Description and Operation

OVERDRIVE

Overdrive is the normal selector position for most forward driving conditions. This position provides all automatic shifts (first through fourth), application and release of the torque converter clutch and maximum fuel economy during normal operation. Overdrive may be cancelled by depressing the Transmission Control Switch (TCS) on the end of the gear selector lever. With overdrive cancelled, the transmission will allow automatic shifts from first through their gears only. Overdrive shifting through all four gears may be activated again by depressing the TCS. This should be done at closed throttle for best shift response.

Transmission Control Switch (TCS)

The transmission control switch is momentary contact switch. When the switch is pressed, a signal is sent to the PCM to allow automatic shifts from first through fourth gears or first through third gears only. The PCM then energizes the transmission control indicator lamp (TCIL).