For 1990-2009 cars
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Control Module References

### Circuit Description

The automatic transmission fluid temperature (TFT) sensor is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The TFT sensor is a resistor, or thermistor, which changes value based on temperature. The sensor has a negative-temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases, the resistance increases. The powertrain control module (PCM) supplies a 5-volt reference signal to the sensor on the TFT sensor signal circuit and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the PCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. The PCM uses this information to control shift quality and torque converter clutch apply.

When the PCM detects a continuous open or short to voltage in the TFT signal circuit or the TFT sensor, then DTC P0713 sets. DTC P0713 is a type C DTC.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Voltage

### Conditions for Running the DTC

• | The ignition is ON.

• | No vehicle speed sensor (VSS) DTCs P0502, P0503.

• | Output (shaft) speed sensor (OSS) greater than 100 RPM for 300 seconds cumulative.

• | Torque converter clutch (TCC) Slip Speed greater than 100 RPM for 300 seconds cumulative.

### Conditions for Setting the DTC

The TFT sensor indicates a signal voltage greater than 4.92 volts for 13 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 commands increased line pressure.

• | The PCM freezes transmission adapt functions.

• | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.

• | The PCM stores DTC P0713 in PCM history.

### Conditions for Clearing the DTC

• | A scan tool can clear the DTC.

• | The PCM clears the DTC from PCM history if the vehicle completes 40 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 DTC passes.

### Test Description

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

1. This step tests the TFT sensor signal circuit for being shorted to another circuit within the transmission. If the TFT sensor signal circuit shorts to another circuit, which is carrying voltage greater than five volts, the TFT sensor would become open.

2. This step tests the TFT sensor signal circuit for being shorted to voltage, which would be the cause for the open in the TFT sensor.

#### DTC P0713

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.

Important: Before clearing the DTC, use the scan tool in order to record the DTC Failure Records. Using the Clear Info function erases the Failure Records from the powertrain control module (PCM).

3. Record the DTC Failure Records.
4. Clear the DTC.
5. Select Trans. Fluid Temp. on the scan tool.

Does the scan tool display a Trans. Fluid Temp. less than the specified value?

-39°C (-38°F)

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3 |

1. Turn OFF the ignition.
2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
3. Install the J 44152 Jumper Harness (20 pins) on the transmission side of the AT inline 20-way connector.
4. Using the DMM and the J 35616 GM Terminal Test Kit, measure the resistance between the TFT sensor signal and low reference circuits of the J 44152 . Refer to Testing for Continuity .

Refer to Automatic Transmission Inline 20-Way Connector End View .

Does the resistance measure less than the specified value?

100 K ohms

Go to Step 7

Go to Step 4

4 |

1. Test the signal circuit of the TFT sensor for an open between the AT inline 20-way connector and the TFT sensor.
2. Test the low reference circuit of the TFT sensor for an open between the AT inline 20-way connector and the TFT sensor.

Refer to Testing for Continuity .

Did you find an open condition?

--

Go to Step 8

Go to Step 5

5 | Measure the resistance between the TFT sensor signal circuit and all other terminals of the J 44152 . Refer to Testing for Continuity . Does the resistance measure less than the specified value? | 1,000 ohms | Go to Step 10 | Go to Step 6
6 | Test the signal circuit of the TFT sensor for a short to voltage between the PCM and the AT inline 20-way connector. Refer to Testing for a Short to Voltage and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 9
7 |

1. Test the signal circuit of the TFT sensor for an open between the PCM and the AT inline 20-way connector.
2. Test the low reference circuit of the TFT sensor for an open between the PCM and the AT inline 20-way connector.

Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct an open condition?

--

Go to Step 12

Go to Step 11

8 | Replace the automatic transmission wiring harness. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
9 | Replace the TFT sensor. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
10 |

1. Replace the automatic transmission wiring harness.
2. Replace the TFT sensor.

Refer to Valve Body and Pressure Switch Replacement .

Did you complete the replacements?

--

Go to Step 12

--

11 | Replace the PCM. Refer to Control Module References . Did you complete the replacement? | -- | Go to Step 12 | --
12 | Perform the following procedure in order to verify the repair:

1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:

• | Turn ON the ignition, with the engine OFF.

• | The Trans. Fluid Temp. must be greater than -40°C (-40°F) for 6 seconds.

4. Select Specific DTC.
5. Enter DTC P0713.

Has the test run and passed?

--

Go to Step 13

Go to Step 2

13 | With the scan tool, observe the stored information, capture info, and DTC Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK