P0713

Diagnostic Chart:

Diagnostic Chart (cont'd):

Wiring Diagram:

Circuit Description
The Transmission Fluid Temperature (TFT) sensor is a thermistor that controls the signal voltage to the PCM. The PCM supplies a 5-volt reference signal to the sensor on circuit 1227. When the transmission is fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid temperature warms to the normal operating temperature, the sensor resistance decreases and the voltage decreases to about 1.5-2 volts.

When the PCM detects a continuous open or short to the power in the TFT signal circuit or the TFT Sensor, then DTC P0713 sets. DTC P0713 is a type B DTC.

Conditions for Setting the DTC

^ The TFT Sensor indicates a voltage greater than 4.92 volts.
^ The ignition is ON.
^ All conditions met for 50.5 seconds.

Action Taken When the DTC Sets

^ The transmission default temperature is 140°C (275°F). The scan tool does not display the default temperature.
^ The PCM freezes 1-2 shift adapts from being updated.
^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the DTC

^ The PCM turns off the MIL after three consecutive ignition cycles without a failure reported.
^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

^ Inspect the harness for a faulty connection or an open in circuit 1227.
^ Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following conditions:

- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation

^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
^ The scan tool displays the transmission fluid temperature in degrees. After the transmission operates, the temperature rises steadily. The temperature then stabilizes.
^ Test the TFT Sensor at the various temperatures in order to evaluate the possibility of a skewed (mis-scaled) sensor. Use the temperature to resistance value scale. A skewed sensor may cause firm shifts or TCC complaints.
^ First diagnose and clear any engine DTCs or Accelerator Pedal Position (APP) Sensor codes that are present. Then inspect for any transmission DTCs that may have reset.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

3. This step verifies a problem in the TFT sensor circuit.
4. This step simulates a TFT Sensor DTC P0712. If the PCM recognizes the low signal voltage (high temperature), and the scan tool displays 146°C (295°F) or greater, the PCM and the wiring are OK.
5. This step inspects the TFT sensor and the internal wiring harness.