Ranger 4WD V6-3.0L VIN V Flex Fuel (1999)
Transmission Temperature Sensor/Switch: Description and Operation
TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR
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The Transmission Fluid Temperature (TFT) sensor is a thermistor-type sensor that varies a reference voltage signal. The resistance in the TFT
varies with temperature. The Powertrain Control Module (PCM) monitors the voltage signal across the TFT, and uses this information to
determine the transmission fluid temperature.
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The TFIF is located on the main control body wiring harness assembly.
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The PCM uses the TFT signal to help determine shift scheduling, torque converter clutch operation and Electronic Pressure Control (EPC).
It sends a voltage signal to the powertrain control module. The voltage signal varies with transmission fluid temperature. The PCM uses this signal to
determine whether a cold start shift schedule is necessary. The shift schedule is compensated when the transmission fluid temperature is cold.
The PCM also inhibits Torque Converter Clutch (TCC) operation at low transmission fluid temperatures and corrects electronic pressure control.