GM Service Manual Online
For 1990-2009 cars only

Object Number: 1246909  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 thermistor. The powertrain control module (PCM) supplies a 5 volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the PCM senses lower voltage. The PCM uses the TFT reading in order to control the torque converter clutch (TCC), line pressure adjustments, and temperature compensated shifts. When the PCM detects no voltage change in the TFT sensor circuit, DTC P0711 sets. DTC P0711 is a type C DTC.

Conditions for Running the DTC

The following conditions must be met for 5 minutes or greater.

Case 1 - Temperature Stuck Low

    • No ECT DTC P0116, P0117, or P0118.
    • No VSS DTCs P0501 or P0502.
    • No TFT DTCs P0712 or P0713.
    • The system voltage is 11 volts or greater.
    • ECT is less than 35°C (95°F) at engine startup, then ECT is greater than 70°C (158°F).
    • TFT at engine start-up is -20°C (-4°F) or below: TFT does not exceed -20°C (-4°F) with all the enable conditions are met.
    • TFT at engine start-up is -20°C (-4°F) or more: TFT does not change more than 5°C (9°F) with all the enable conditions are met.
    • The vehicle speed is 30 km/h (19 mph) or greater.
    • The APP angle is 10% or greater.

Case 2 - Temperature Stuck High

    • No ECT DTC P0116, P0117, or P0118.
    • No VSS DTCs P0501 or P0502.
    • No TFT DTCs P0712 or P0713.
    • The system voltage is 11 volts or greater.
    • ECT is greater than 70°C (158°F) at last ignition, 35°C (95°F) or less at engine start-up, then ECT is greater than 70°C (158°F).
    • TFT is 110°C (230°F) or greater at last ignition and at engine start-up, for 20 seconds.

Conditions for Setting the DTC

Case 1

The change in TFT is less than 5°C (9°F) since start-up, for 5 minutes after the conditions for running the DTC are met.

Case 2

The change in TFT is less than 5°C (9°F) since start-up, for 20 seconds after the conditions for running the DTC are met.

Action Taken When the DTC Sets

    • The PCM does not illuminate the malfunction indicator lamp (MIL).
    • The PCM illuminates the SVS Lamp.
    • The PCM ignores the input from TFT sensor and uses the default values.
    • 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 P0711 in PCM history.

Conditions for Clearing the SVS Lamp/DTC

    • The PCM turns OFF the SVS lamp when the condition no longer exists.
    • A scan tool can clear the SVS lamp 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.

Diagnostic Aids

    • Inspect the connectors at the PCM, the TFT sensor, and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents in Wiring Systems.
    • Inspect for a shorted TFT sensor wire.
    • Inspect for a faulty TFT sensor.
    • Inspect for an internal fault of the PCM.

Test Description

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

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

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 3.5L (L66)

2

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.
  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 PCM.

  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 the following condition: The TFT does not change greater than 5°C (9°F) in 5 minutes and 20 seconds since start-up.

Did the condition occur?

--

Go to Step 4

Go to Intermittent Conditions in Engine Controls-3.5L (L66)

4

  1. Turn OFF the ignition.
  2. Disconnect the TFT sensor.
  3. Turn ON the ignition, with the engine OFF.

Did the scan tool display a condition in which the Trans. Fluid Temp. does not change by greater than the specified value in 5 minutes and 20 seconds since start-up?

5°C (9°F)

Go to Step 6

Go to Step 5

5

Replace the TFT sensor.

Refer to Transmission Fluid Temperature Sensor Replacement .

Did you complete the replacement?

--

Go to Step 7

--

6

Replace the PCM.

Refer to Powertrain Control Module Replacement in Engine Controls - 3.5L (L66).

Did you complete the replacement?

--

Go to Step 7

--

7

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 TFT is between -30 and +143°C (-22 and +289°F).
    • The TFT changes by greater than 2°C (4°F) since start-up for 5 minutes.
  5. Select Specific DTC.
  6. Enter DTC P0711.

Has the test run and passed?

--

Go to Step 8

Go to Step 2

8

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) Types in Engine Controls - 3.5L (L66)

System OK