Transmission Temperature Sensor/Switch: Description and Operation

Trans Fluid Temp (TFT) Sensor:

DESCRIPTION
The Transmission Fluid Temperature (TFT) sensor is a thermistor (a device that changes resistance according to changes in temperature) used to indicate transmission fluid temperature. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. The Powertrain Control Module (PCM) uses the TFT sensor signal input to determine the following:

- Torque Converter Clutch (TCC) apply and release schedules.
- Hot mode determination.
- Shift quality.

The TFT sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission.