For 1990-2009 cars
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### 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 808 results in high signal voltage. The TFT operating range is -40 to +151°C (-40 to +304°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 system voltage is 9-16 volts.

• | The ignition is ON.

• | The PCM detects a TFT sensor voltage of 4.92 volts for 7 minutes continuous.

### Action Taken When the DTC Sets

• | The PCM does not turn on the Malfunction Indicator Lamp (MIL).

• | The PCM disables shift adapts.

• | The default TFT will be determined through the following calculations:

- | If the Engine Run Time is less than 3 minutes and:

• | Intake Air Temperature (IAT) DTC P0112, P0113, P1111 or P1112 is set, then the default Automatic Transmission Fluid Temperature (TFT) is 0°C (32°F).

• | No IAT DTC is set, then the default TFT is set to the IAT saved at start up.

- | If the Engine Run Time is greater than 3 minutes, and an Engine Coolant Temperature (ECT) DTC P0117, P0118, P1114 or P1115 is set, then the default TFT is 131°C (268°F).

- | If the Engine Run Time is greater than 3 minutes, no ECT DTC is set and:

• | The ECT is less than 45°C (113°F), then the default TFT is 12°C (54°F).

• | The ECT is greater than 115°C (239°F), then the default TFT is 131°C (268°F).

• | The ECT is 45-115°C (113-239°F) and:

- | The IAT DTC P0112, P0113, P1111 or P1112 is set, then the default TFT is set to equal the ECT.

- | The IAT at start up is less than 0°C (32°F), then the default TFT is set to ECT minus 10°C (18°F).

- | The IAT at start up is greater than 28°C (82°F), then the default TFT is set to ECT plus 10°C (18°F).

- | The IAT at start up is 0-28°C (32-82°F), then the default TFT is set to equal ECT.

### 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 for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following problems:

- | A bent terminal

- | A backed out terminal

- | A damaged terminal

- | Poor terminal tension

- | Moisture Intrusion

• | When diagnosing for an intermittent open, massage the wiring harness while watching the test equipment for a change.

• | Test the TFT sensor at various temperature levels to evaluate the possibility of a skewed (mis-scaled) sensor. Refer to Temperature vs Resistance chart.

### Test Description

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

1. If the display does not indicate an Automatic Transmission Fluid Temperature Sensor voltage greater than 4.920 volts, inspect the connectors and the terminal for intermittent problems.

2. Important: After 10 seconds, the Scan Tool will display a default temperature.

   This step inspects only the engine harness and the PCM for an open.

#### DTC P0713 Transmission Fluid Temperature Sensor Circuit -- High Input

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls
2 | Has the transmission fluid checking procedure been performed? | -- | Go to Step 3 | Go to Transmission Fluid Check
3 |

1. Install the Scan Tool .
2. With the engine OFF, turn the ignition switch to the RUN position.

Important: Before clearing the DTCs, use the Scan Tool in order to record the Failure Records for reference. The Clear Info function will erase the data.

3. Record the DTC Failure Records, then clear the DTC(s).
4. Select TFT Sensor volts on the Scan Tool .

Does the Scan Tool display an Automatic Transmission Fluid Temperature voltage greater than the specified value?

4.920 volts

Go to Step 4

Go to Diagnostic Aids

4 |

1. Turn the ignition OFF.
2. Disconnect the transmission 20-way connector.
3. Connect a J 36169-A Fused Jumper Wire from terminal L (YEL/BLK) to terminal M (BLK) of the engine harness.
4. Turn the ignition ON, and keep the engine OFF.

Does the Scan Tool display a TFT voltage greater than the specified value?

4.92 volts

Go to Step 5

Go to Step 7

5 | Inspect circuit 1227 (YEL/BLK) of the engine wiring harness for an open. Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6
6 | Inspect circuit 808 (BLK) of the engine wiring harness for an open. Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10
7 |

1. Inspect circuit 1227 (BRN) of the Automatic Transmission Wiring Harness for an open.
2. Inspect circuit 452 (GRY) of the Automatic Transmission Wiring Harness for an open.

Refer to General Electrical Diagnosis in Wiring Systems.

Did you find the condition?

--

Go to Step 9

Go to Step 8

8 | Replace the Automatic Transmission Fluid Temperature Sensor. Refer to Fluid Temperature Sensor Replacement Is the replacement complete? | -- | Go to Step 11 | --
9 | Replace the Automatic Transmission Wiring Harness. Refer to Solenoids and Wiring Harness Replacement . Is the replacement complete? | -- | Go to Step 11 | --
10 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | Go to Step 11 | --
11 | In order to verify your repair, using the Scan Tool , perform the following procedure:

1. Select DTC.
2. Select Clear Info, then clear the DTC(s).
3. Operate the vehicle so that the TFT Sensor voltage is less than 4.920 volts for more than 7 minutes.
4. Select Specific DTC.
5. Enter DTC P0713.

Has the test run and passed?

--

System OK

Go to Step 1