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, an open TFT sensor or open circuits 1227 or 808/452 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 Running the DTC

The system voltage is 9-18 volts.

### Conditions for Setting the DTC

The PCM detects a TFT sensor voltage greater than 4.92 volts for 6 minutes and 40 seconds continuous.

### Action Taken When the DTC Sets

• | The PCM does not turn on the malfunction indicator lamp (MIL).

• | The PCM freezes shift adapts.

• | The PCM calculates a default TFT from the ECT sensor and the IAT sensor.

• | 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 non-emission-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 all other circuit connecting points 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

- | Corrosion

• | 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 the Temperature vs Resistance table.

### Test Description

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

1. If the display does not indicate a TFT sensor voltage greater than 4.92 volts, inspect the connector and the terminals for intermittent conditions.

2. Important: After 10 seconds, the scan tool will display a default temperature.

   This step tests the integrity of the engine harness and the PCM by using a fused jumper wire from terminal L to terminal M. Voltage should be less than 0.2 volts.

3. Because of the harsh conditions inside the transmission, repairing the automatic transmission (A/T) wiring harness assembly is not acceptable. It must be replaced if it is damaged in any way.

#### DTC P0713 TFT 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 | Was the transmission fluid checking procedure performed? | -- | Go to Step 3 | Go to Transmission Fluid Check
3 |

1. Install the Scan Tool .
2. 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. Using the Clear Info function will erase the stored Failure Records from the PCM.

3. Record the Failure Records.
4. Clear the DTCs.
5. Monitor TFT sensor on the scan tool.

Does the scan tool display a TFT sensor voltage greater than the specified value?

4.92 volts

Go to Step 4

Go to Diagnostic Aids

4 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the transmission 20-way connector.
3. Connect a fused jumper wire from terminal L to terminal M of the engine wiring harness.

Refer to AT Inline Harness Connector End View.

Important: Additional DTCs will set.

4. Turn the ignition switch to the RUN position.

Does the scan tool display a TFT sensor 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. Was a condition found? | -- | Go to Step 8 | 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. Was a condition found? | -- | Go to Step 8 | Go to Step 11
7 |

1. Inspect circuit 1227 (BRN) of the automatic transmission wiring harness assembly for an open.
2. Inspect circuit 452 (GRY) of the automatic transmission wiring harness assembly for an open.

Refer to General Electrical Diagnosis in Wiring Systems.

Was a condition found?

--

Go to Step 10

Go to Step 9

8 | Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 12 | --
9 | Replace the automatic transmission fluid temperature sensor. Refer to Fluid Temperature Sensor Replacement . Is the replacement complete? | -- | Go to Step 12 | --
10 | Replace the automatic transmission wiring harness assembly. Refer to Solenoids and Wiring Harness Replacement . Is the replacement complete? | -- | Go to Step 12 | --
11 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | Go to Step 12 | --
12 | Perform the following procedure in order to verify the repair:

1. Select DTC.
2. Select Clear Info.
3. Road test the vehicle.
4. Monitor TFT sensor on the scan tool. Ensure that the TFT sensor voltage is between 0.2 and 4.92 volts for at least 6 minutes and 40 seconds.
5. Select Specific DTC.
6. Enter DTC P0713.

Has the test run and passed?

--

System OK

Go to Step 1