P0713

Circuit Description

The automatic transmission fluid temperature (TFT) sensor is a negative coefficient thermistor whose resistance value changes based on temperature. The 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 Running 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).

Conditions for Setting the DTC

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).
^ The PCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time.
^ The PCM stores DTC P0713 in PCM history.

Conditions for Clearing the DTC

^ A scan tool clears the DTC from PCM history.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 consecutive warm-up cycles without a nonemission-related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch 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 2-way connector for the following conditions:
- A backed out terminal
- A damaged terminal
- Reduced 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.