For 1990-2009 cars

### Circuit Description

The automatic transmission fluid temperature (TFT) sensor is a negative coefficient thermistor. When the transmission fluid is cold, the sensor resistance is increases. As the transmission fluid warms up, the sensor resistance decreases. This diagnostic monitors the TFT circuit. The circuit may be functional, but not in the normal operating range. This diagnostic indicates stuck, erratic, intermittent, skewed, or inaccurate values, indicating poor system performance. The TFT range is -40 to +151°C (-40 to +305°F).

If the transmission control module (TCM) detects rapid or no voltage changes in the TFT sensor circuit, then DTC P0711 sets. DTC P0711 is a type C DTC.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0711 Transmission Fluid Temperature (TFT) Sensor Performance

### Conditions for Running the DTC

#### Condition 1, 2 and 4

• | DTCs P0716, P0717, P0722, P0723 are not set.

• | DTC P0711 fails this ignition cycle test.

• | The ECT is normal, ignition voltage in START, engine idling.

• | The TCM temperature at startup is between -39 to +149°C (-38 to +300°F).

#### Condition 1

• | The TCM temperature at startup is between -40 to +20°C (-40 to +28°F).

• | Engine Coolant Temperature is greater than 70°C (158°F) and has changed by at least 50°C (90°F) since startup.

• | After starting, vehicle speed is greater than 8 km/h (5 mph) for at least 900 seconds (15 minutes).

#### Condition 2

• | The TCM temperature at startup is between 129-149°C (264-300°F).

• | Engine Coolant Temperature is greater than 70°C (158°F) and has changed by at least 50°C (90°F) since startup.

• | After starting, vehicle speed is greater than 8 km/h (5 mph) for at least 600 seconds (10 minutes).

#### Condition 3

• | The system ignition voltage is between 8-18 volts.

• | The engine speed is between 450-7,500 for 5 seconds.

#### Condition 4

• | APP is correct, engine torque value is correct, engine RPM is correct and ECT is correct.

• | Engine torque value is between 50-1,492 N·m (37-1,108 lb ft).

• | The TP angle is between 8-100 percent.

• | Vehicle speed is between 8-511 km/h (5-320 mph).

• | The engine speed is between 500-6,800 RPM.

• | ECT is between -39 to +149°C (-38 to +300°F).

### Conditions for Setting the DTC

One of the following conditions occurs:

#### Condition 1

• | Vehicle speed is greater than 8 km/h (5 mph) for at least 300 seconds (5 minutes).

• | The TCC slip speed is greater than 120 RPM for 300 seconds (5 minutes).

• | The TCM temperature is between -40 to +21°C (-40 to +70°F).

• | Engine Coolant Temperature is greater than 70°C (158°F) and has changed by at least 55°C (99°F) since startup.

• | The transmission fluid temperature has not changed by more than 2°C (4°F) since startup for 80 seconds (1 minute and 20 seconds).

#### Condition 2

• | Vehicle speed is greater than 8 km/h (5 mph) for at least 300 seconds (5 minutes).

• | The TCC slip speed is greater than 120 RPM for 300 seconds (5 minutes).

• | The TCM temperature is between +129 to +150°C (+264 to +70°F).

• | Engine Coolant Temperature is greater than 70°C (158°F) and has changed by at least 55°C (99°F) since startup.

• | The transmission fluid temperature has not changed by more than 2°C (4°F) since startup for 80 seconds (1 minute and 20 seconds).

#### Condition 3

The transmission fluid temperature has changed by 20°C (36°F) or greater; 14 times within 7 seconds.

#### Condition 4

The change of Transmission fluid temperature is still below 20°C (36°F) or more when it excesses the calibrated time.

### Action Taken When the DTC Sets

• | The TCM does not request the engine control module (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 P0711 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 for an intermittent short or open condition in the engine wiring harness. The test light is used as a resistor in the circuit.

2. This step determines if the TCM or the TFT, sensor is causing a steady, unchanging TFT, reading.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Check . Did you perform the Transmission Fluid Checking Procedure? | -- | Go to Step 3 | Go to Transmission Fluid Check
3 |

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 ECM and the TCM Failure Records. Using the Clear Info function erases the Failure Records from the ECM and TCM.

• | Using the Clear Info function erases stored DTCs in both the ECM and TCM.

3. Record the DTC Failure Records.
4. Clear the DTC.
5. Select Trans. Fluid Temp. on the scan tool.
6. Drive the vehicle and observe the scan tool for either of the following conditions:

• | The TFT does not change greater than 2°C (4°F) in 1 minute and 40 seconds since startup.

• | The TFT changes by 20°C (36°F) or greater in 0.250 second, 14 times within 7 seconds, unrealistic change.

Did either of the conditions occur?

--

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections

4 | Does the scan tool display that Trans. Fluid Temp. does not change by greater than the specified value in 1 minute and 20 seconds since startup? | 2°C (4°F) | Go to Step 6 | Go to Step 5
5 |

1. Turn OFF the ignition.
2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
3. Install the J 45681 jumper harness on the engine side of the AT inline 20-way connector.
4. Using the GM terminal test kit, connect a test light between the TFT sensor signal circuit and the low reference circuit of the J 45681 .
5. Turn ON the ignition, with the engine OFF.
6. While observing the scan tool display, move or wiggle the engine wiring harness from the TCM connector to the AT inline 20-way connector.

Does the Trans. Fluid Temp. change by greater than the specified value?

20°C (36°F)

Go to Step 7

Go to Step 8

6 |

1. Turn OFF the ignition.
2. Disconnect the AT inline 20-way connector.
3. Turn ON the ignition, with the engine OFF.

Did the scan tool display that Trans. Fluid Temp. does not change by greater than the specified value in 1 minute and 20 seconds since startup?

2°C (4°F)

Go to Step 9

Go to Step 8

7 |

1. Test the TFT signal circuit for an intermittent open or short condition between the TCM connector and the AT inline 20-way connector.
2. Test the TFT low reference circuit for an intermittent open or short condition between the TCM connector and the AT inline 20-way connector.

Refer to Testing for Continuity and Testing for Short to Ground and Wiring Repairs .

Did you find and correct a condition?

--

Go to Step 9

Go to Step 8

8 | Replace the automatic transmission wiring harness. Refer to Transmission Internal Electrical Harness Replacement . Did you complete the replacement? | -- | Go to Step 10 | --
9 | Replace the TCM. Refer to Control Module References . Did you complete the replacement? | -- | Go to Step 10 | --
10 | Perform the following procedure in order to verify the repair:

1. Select DTC.
2. Select Clear Info.
3. Drive the vehicle and ensure the following conditions are met:

• | The transmission fluid temperature is -39 to +149°C (-38 to +300°F).

• | The TFT changes by greater than 2°C (4°F) since startup.

• | The TFT does not change by 20°C (36°F) or greater within 0.250 second.

4. Select Specific DTC.
5. Enter DTC P0711.

Has the test run and passed?

--

Go to Step 11

Go to Step 2

11 | 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