Transmission Fluid Temperature (TFT) Sensor

DESCRIPTION
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.

SYMPTOMS
Torque converter clutch and stabilized shift schedule happens too soon after a cold start. Code P1783 indicates transmission fluid temperature exceeds 132° C (270° F) and results in increased EPC pressure and torque converter clutch engagement. May flash transmission control indicator lamp.

DIAGNOSTIC TROUBLE CODES
P0712, P0713, P1711, P1783