Navigator 4WD V8-5.4L SOHC VIN L (1998)
Transmission Temperature Sensor/Switch: Description and Operation
Transmission Temperature Sensor/Switch, A/T
TRANSMISSION FLUID TEMPERATURE (TFT) SENSOR
The transmission fluid temperature sensor is located on the solenoid body assembly in the transmission sump. It is a temperature-sensitive device
called a thermistor. The resistance value of the transmission fluid temperature sensor will vary with temperature change.
The powertrain control module monitors voltage across the transmission fluid temperature sensor to determine the temperature of the transmission
fluid.
The powertrain control module uses this signal to determine whether a cold start shift schedule is necessary. The cold start shift schedule lowers shift
speeds to allow for the reduced performance of cold engine operation. The powertrain control module also uses the transmission fluid temperature
sensor input to adjust electronic pressure control pressure for temperature effects and to inhibit torque converter clutch operation during the warm-up
period.
