P0713

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The Automatic Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermister 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.

If 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 D DTC

Conditions for Setting the DTC
- The system voltage 1O-16 volts. The ignition is ON.
- The TFT sensor indicates a voltage greater than 4.94 volts.
- All conditions met for 409 seconds

Action Taken When the DTC Sets
- The PCM freezes shift adapts from being updated.
- The PCM does not illuminate the Malfunction Indicator Lamp (MIL).
- The PCM determines a default Transmission Fluid Temperature (TFT) using the following matrix:
- The PCM determines a default Transmission Fluid Temperature (TFT) using the following matrix:
- If any Engine Coolant Temperature (ECT) DTCs P0117, P0118, or P1114, or P1115 are set, then the default TFT is equal to 135°C (275°F).
- If the ECT is 125°C (257°F) or more, then the default TFT is equal to 135°C (275°F).
- If the Engine Run Time is less than 300 seconds, and:
- No Intake Air Temperature (IAT) DTCs P0112 or P0113 are set, and the IAT is available, then the default TFT is equal to the IAT
- Any Intake Air Temperature (IAT) DTCs P0112 or P0113 are set, or the IAT is not available, then the default TFT is equal to 90°C (194°F).
- If the Engine Run Time is greater than 300 seconds, and no Intake Air Temperature (IAT) DTCs P0112 or P0113 are set, and the IAT is available. and the Engine Coolant Temperature (ECT) is 4°l 25 C (l04-257°F) and:
- IAT at start up is less than 15°C (59°F), then the default TFT is equal to the Engine Coolant Temperature (ECT) plus 5°C (8°F).
- IAT at start up is greater than 35°C (95°F), then the default TFT is equal to the Engine Coolant Temperature (ECT) plus 10°C (16°F).
- IAT Tat start up is 15-35°C (59-95°F), then the default TFT is equal to the Engine Coolant Temperature (ECT).
- If the Engine Run Time is greater than 300 seconds, and any Intake Air Temperature DTCs P0112 or P0113 are set, or the IAT is not available then the default TFT is equal to the Engine Coolant Temperature (ECT).
- If the Engine Run Time is greater than 300 seconds, and the ECT is less than 40°C (104°F), then the default TFT is equal to 60°C (140°F).

Conditions for Clearing the DTC
- 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 (YEL/BLK).
- Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring at the 20-way harness. Look for the following problems:

- 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, 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 vs Resistance scale in order to test the TFT sensor at various temperatures. Test the TFT sensor 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. This step verifies that a problem exists in the TFT sensor circuit.
4. This step 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 external wiring are functioning normally.
5. This step tests the TFT sensor and the Automatic Transmission wiring harness.