P0713

Diagnostic Chart (cont'd):

Diagnostic Chart (cont'd):

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Automatic Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermistor within the Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch. The TFT controls the signal voltage from the PCM. The PCM supplies a 5 volt reference signal to the TFT sensor on circuit 1227. When the transmission fluid is cold, the sensor resistance is high. The PCM detects high signal voltage. As the transmission fluid warms, the sensor resistance decreases and the detected voltage decreases. At the transmission's normal operating temperature of 100°C (212°F) the voltage is approximately 1.5-2 volts.

When the PCM detects a continuous open or short to 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 system voltage 10-17 volts.

- The ignition is ON.

- The TFT sensor indicates a voltage greater than 4.94 volts.

- All conditions met for 400 seconds


ACTION TAKEN WHEN THE DTC SETS

- The transmission default temperature becomes 135°C (275°F).

- The freeze shift adapts from being updated.

- The PCM illuminates the Malfunction Indicator Lamp (MIL).


CONDITIONS FOR CLEARING THE MIL/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 4227.

- Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring at the 20-way harness. 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 test equipment for changes.

- The scan tool displays the transmission fluid temperature in degrees. After the transmission is operating, the temperature should rise steadily to about 100°C (212°F).

- Use the temperature versus resistance scale in order to test the TFT sensor at various temperatures. Test the TFT sensor at the various temperatures in order to eliminate the possibility of a skewed (mis-scaled) sensor. A skewed sensor can result in firm shifts or TCC complaints.

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic chart.

3. Step 3 verifies that a problem exists in the TFT sensor circuit.

4. Step 4 simulates a TFT sensor DTC P0712. If the PCM receives the low signal voltage (indicating high temperature), and the scan tool displays 146°C (296°F) or greater, then the PCM and wiring are functioning normally.

5. Step 5 tests the TFT sensor and the Automatic Transmission wiring harness.