GM Service Manual Online
For 1990-2009 cars only

Object Number: 1746367  Size: MF
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 automatic TFT sensor is a negative coefficient thermistor. When the transmission fluid is cold, the sensor resistance is high. 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

    • No ECT DTC P0115.
    • DTC P0711 has not passed in the current ignition cycle.
    • No OSS DTCs P0722 or P0723.
    • The engine run time is greater than 5 seconds.
    • The transmission fluid temperature is -39°C to +149°C (-38°F to +300°F).
    • For conditions 1 and 2 below, the engine coolant temperature is greater than 70°C (158°F) and has changed by at least 55°C (90°F) since startup.
    • For conditions 1 below, the TCC slip speed is 120 RPM or greater for 300 seconds (5 minutes) cumulatively.

Conditions for Setting the DTC

One of the following conditions occurs:

Condition 1

    • The transmission fluid temperature at startup is -40° to +20°C (-40° to +70°F).
    • The TCC slip speed is greater than 120 RPM for 300 seconds (5 minutes) cumulatively.
    • 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

    • The transmission fluid temperature at startup is 129-150°C (264-302°F).
    • The vehicle speed is greater than 8 km/h (5 mph) for 300 seconds (5 minutes) cumulatively.
    • 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) 14 times within 7 seconds.

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 lamp 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.

DTC P0711

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

Inspect for correct transmission fluid level.

Refer to Transmission Fluid Check .

Did you perform the 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.
  3. Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the TCM.

  4. Record the DTC Failure Records.
  5. Clear the DTC.
  6. Select Trans. Fluid Temp. on the scan tool.
  7. Drive the vehicle and observe the scan tool for either of the following conditions:
  8. • The Trans. Fluid Temp. does not change more than 2.25°C (4°F) in 300 seconds since startup.
    • The Trans. Fluid Temp. changes more than 20°C (36°F) 14 times within 7 seconds.

Did either of the conditions occur?

--

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections

4

Did the scan tool display a condition in which the Trans. Fluid Temp. does not change by more than the specified value in 300 seconds since startup?

2°C (36°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 44152 Jumper Harness (20 pins) on the engine side of the AT inline 20-way connector.
  4. Using the J 35616 GM Terminal Test Kit, connect a test lamp between the TFT sensor signal and low reference circuits of the J 44152 .
  5. Refer to Automatic Transmission Inline 20-Way Connector End View .

  6. Turn ON the ignition, with the engine OFF.
  7. While observing the scan tool display, move or wiggle the engine wiring harness from TCM to the AT inline 20-way connector.

Does the scan tool Trans. Fluid Temp. change by more than the specified value?

20°C (68°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.

Does the scan tool display the same condition as in Step 4?

--

Go to Step 11

Go to Step 10

7

  1. Test the TFT sensor signal circuit of the TFT sensor for an intermittent open or short condition between the TCM and the AT inline 20-way connector.
  2. Test the low reference circuit of the TFT sensor for an intermittent open or short condition.
  3. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

8

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

Refer to Circuit Testing .

Did you find an intermittent open or short condition?

--

Go to Step 9

Go to Step 10

9

Replace the AT wiring harness.

Refer to Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness .

Did you complete the replacement?

--

Go to Step 12

--

10

Replace the TFT sensor, this sensor is part of the TFP manual valve position switch.

Refer to Valve Body and Pressure Switch Replacement .

Did you complete the replacement?

--

Go to Step 12

--

11

Replace the TCM.

Refer to Control Module References for replacement, setup, and programming.

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. Drive the vehicle and ensure the following conditions are met:
  4. • The Trans. Fluid Temp. changes by more than 3°C (5.4°F) for 5 seconds since startup.
    • The Trans. Fluid Temp. does not change by more than 20°C (36°F) within 200 milliseconds for a period of at least 11 seconds.
  5. Select Specific DTC.
  6. Enter DTC P0711.

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