Transmission Fluid Temperature (TFT) Sensor
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The automatic transmission fluid temperature (TFT) sensor is a thermistor. The powertrain control module (PCM) supplies a 5 volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the PCM senses lower voltage. The PCM uses the TFT reading in order to control the torque converter clutch (TCC), line pressure adjustments, and temperature compensated shifts. Refer to Transmission Fluid Temperature Sensor Specifications