GM Service Manual Online
For 1990-2009 cars only

Object Number: 656029  Size: MF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description 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. A low fluid temperature, an open TFT sensor or sensor circuit results in high signal voltage. The TFT operating range is -40°C to +151°C (-40°F 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 C 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 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. A value above 4.9 volts indicates the fault is present. A value below 4.9 volts indicates the fault is intermittent.

  2. A value of 4.9-5.0 volts indicates the PCM and engine side of the wiring are good.

  3. A short to voltage greater than 5.0 volts will cause the TFT sensor to open.

  4. A short between the TFT sensor signal circuit and any other circuit in the transmission harness could cause the TFT sensor to open.

DTC P0713 TFT Sensor Circuit High Input

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls

2

  1. Install a Scan Tool .
  2. Turn ON the ignition with the engine OFF.
  3. 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.

  4. Record the Failure Records.
  5. Clear the DTCs.
  6. With a Scan Tool , observe the TFT Sensor parameter.

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

4.9 V

Go to Step 3

Go to Intermittent Conditions in Engine Controls

3

  1. Turn OFF the ignition.
  2. Disconnect the AT inline 20-way connector.
  3. Connect the J 44152 jumper harness to the engine side of the 20-way connector.
  4. Using the J 35616 connector test adapter kit, connect a J 39200 digital multimeter (DMM) from terminal L to terminal M of the J 44152 jumper harness.
  5. Refer to Automatic Transmission Inline Harness Connector End View .

  6. Turn ON the ignition with the engine OFF.
  7. Observe the voltage on the J 39200 DMM.

Does the voltage measure within the specified range?

4.9-5.0 V

Go to Step 7

Go to Step 4

4

Does the voltage in Step 3 measure more than the specified value?

5.0 V

Go to Step 6

Go to Step 5

5

  1. Test the signal circuit (CKT 1227) of the TFT sensor for an open between the PCM and the AT inline 20-way connector.
  2. Test the low reference circuit (CKT 808) of the TFT sensor for an open between the PCM and the AT inline 20-way connector.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

6

Test the signal circuit (CKT 1227) of the TFT sensor for a short to power between the PCM and the AT inline 20-way connector.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 13

7

  1. Turn OFF the ignition.
  2. Disconnect the AT inline 20-way connector (additional DTCs may set).
  3. Install the J 44152 jumper harness on the transmission side of the 20-way connector.
  4. Using the J 39200 DMM, measure the resistance between terminals L and M of the J 44152 jumper harness.
  5. Refer to Automatic Transmission Inline Harness Connector End View .

Is the resistance less than the specified value?

100 K ohms

Go to Step 9

Go to Step 8

8

  1. Test the signal circuit (CKT 1227) of the TFT sensor for an open between the AT inline 20-way connector and the TFT sensor.
  2. Test the low reference circuit (CKT 452) of the TFT sensor for an open between the AT inline 20-way connector and the TFT sensor.

Refer to Circuit Testing in Wiring Systems.

Did you find the condition?

--

Go to Step 10

Go to Step 12

9

Measure the resistance between terminal L and all other terminals, except M, of the J 44152 jumper harness.

Is the resistance between terminal L and all other terminals, except M, greater than the specified value?

1000 ohms

Go to Intermittent Conditions in Engine Controls

Go to Step 10

10

Replace the automatic transmission wiring harness assembly.

Refer to Wiring Harness Replacement .

Did you complete the replacement?

--

Go to Step 11

--

11

Was the engine harness repaired, or the transmission harness replaced due to a short to power or other circuit?

--

Go to Step 12

Go to Step 14

12

Replace the automatic transmission fluid temperature sensor.

Refer to Fluid Temperature Sensor Replacement .

Did you complete the replacement?

--

Go to Step 14

--

13

Replace the PCM.

Refer to Powertrain Control Module Replacement in Engine Controls.

Did you complete the replacement?

--

Go to Step 14

--

14

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Turn ON the ignition with the engine OFF.
  4. The TFT sensor voltage must be less than 4.9 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