P0713

Circuit Description
The Automatic Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermistor whose resistance value changes based on temperature. The Powertrain Control Module (PCM) provides a 5 volt reference to the sensor on circuit 1227. A low fluid temperature or open circuits 1227 or 452 result in high signal voltage. The TFT operating range is -40 to +151°C (40 to +305°F).

If the PCM detects a continuous open or a short to power on the TFT sensor circuit, then DTC P0713 sets. DTC P0713 is a Type D DTC.

Conditions for Setting the DTC
^ The engine run time is greater than 5 minutes.
^ The vehicle speed is greater than 16 km/h (10 mph) for 5 minutes.
^ The engine coolant temperature is greater than 25°C (-13°F).
^ The PCM detects a reading of -40°C (-40°F) or less (5.04 volts or greater) for 6 seconds.

Action Taken When the DTC Sets
^ The PCM does not illuminate the Malfunction Indicator Lamp (MIL).
^ If any engine coolant temperature sensor codes set, the PCM substitutes a transmission fluid temperature default value of 132°C (269°F).
^ If the engine coolant temperature is greater than 115°C (239°F), the PCM substitutes a transmission fluid temperature default value of 132°C (269°F). This enables Transmission Hot Mode. The transmission remains in Hot Mode until the engine coolant temperature drops below 110°C (230°F).
^ If the engine run time is less than 3 minutes, the PCM substitutes the intake air temperature for the transmission fluid temperature value at ignition ON.
^ If the engine coolant temperature is 45-115°C (113-239°F), the transmission fluid default temperature equals ECT-10°0 when the intake air temperature is less than 27°C (81°F) at ignition ON. If the intake air temperature is greater than 27°C (81°F) at ignition ON, the transmission fluid default temperature equals ECT+10°C.
^ If engine run time is greater than 3 minutes and the engine coolant temperature is less than 45°C (113°F), the PCM substitutes a transmission fluid temperature default value of 12°C (54°F).
^ DTC P0713 is stored in the PCM history.

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 wiring at the PCM, the transmission 20-way connector, and the TFT sensor -way connector, 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
- Moisture intrusion
^ When diagnosing for an intermittent open, massage the wiring harness while watching the test equipment for a change.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. If the display does not indicate a TFT sensor voltage greater than 4.98 volts, inspect the connectors and the terminal for intermittent conditions.

Important: After 7 seconds, the scan tool will display a default temperature.

4. This step isolates the automatic transmission wiring harness by using a fused jumper from terminal M to the transmission case. Inspect the engine wiring harness circuit 1227 and circuit 452 for an open.