GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category

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 thermistor, or a resistor that changes value when the temperature changes. 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 transmission control module (TCM) supplies a 5-volt reference signal to the sensor and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the TCM detects high signal voltage. As the fluid temperature increases, the resistance of the sensor decreases, which lowers the signal voltage.

If the TCM detects an open in the TFT sensor or signal circuit, 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

    • No ISS DTCs P0716 or P0717.
    • No OSS DTCs P0722, P0723.
    • The output shaft speed is greater than 200 RPM for 200 seconds (3 minutes and 20 seconds) cumulative.
    • The TCC slip speed is greater than 120 RPM for 200 seconds (3 minutes and 20 seconds) cumulative.
    • The engine run time is greater than 5 seconds.

Conditions for Setting the DTC

The TCM detects a transmission fluid temperature of -39° C (-38° F) or less for 25 seconds.

Action Taken When the DTC Sets

    • The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
    • The TCM freezes transmission adaptive functions.
    • The TCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time.
    • The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
    • The TCM stores DTC P0713 in TCM history.

Conditions for Clearing the DTC

    • A scan tool can clear the DTC.
    • The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
    • The TCM 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 5-volts, the TFT sensor will become open.

  2. This step tests the TFT sensor signal circuit for being shorted to voltage, which will 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.
  3. 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 transmission control module (TCM).

  4. Record the DTC Failure Records.
  5. Clear the DTC.
  6. 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 A/T inline 20-way connector. Additional DTCs may set.
  3. Install the J 44152 Jumper Harness (20 pins) on the transmission side of the A/T inline 20-way connector.
  4. Using the DMM and the J 35616 , measure the resistance between the transmission fluid temperature (TFT) sensor signal and low reference circuits of the J 44152 . Refer to Testing for Continuity .

Refer to Component Connector End Views .

Does the resistance measure less than the specified value?

100 K Ω

Go to Step 7

Go to Step 4

4

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

Go to Step 10

Go to Step 6

6

Test the signal circuit of the TFT sensor for a short to voltage between the TCM and the A/T 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 TCM and the A/T inline 20-way connector.
  2. Test the low reference circuit of the TFT sensor for an open between the TCM and the A/T 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 TCM. 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:
  4. • Turn ON the ignition, with the engine OFF.
    • The Trans. Fluid Temp. must be greater than -40°C (-40°F) for 6 seconds.
  5. Select Specific DTC.
  6. 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