GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

DTC Descriptors

DTC P0711: Transmission Fluid Temperature (TFT) Sensor Performance

DTC P0712: Transmission Fluid Temperature (TFT) Sensor Circuit Low Voltage

DTC P0713: Transmission Fluid Temperature (TFT) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

TFT Sensor Signal

P0712

P0713

P0713

P0711

Low Reference

--

P0713

--

P0711

Typical Scan Tool Data

Trans. Fluid Temp.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Engine running in Park, normal operating temperature

Parameter Normal Range: -39 to +149°C (-38 to +300°F)

TFT Signal

Greater than 149°C (300°F)

Less than -39°C (-38°F)

Less than -39°C (-38°F)*

Low Reference

--

Less than -39°C (-38°F)

Less than -39°C (-38°F)*

* Internal TFT sensor damage may result if shorted to B+

Circuit/System Description

The primary source of heat in the transmission is the drive motor generators. The drive motor generators are cooled by the transmission fluid. Hot fluid exits the drive motor generators and flows to the transmission cooler supply line. The supply line connects to the cooler, which is in front of the radiator. The transmission fluid cooler pipe assembly is equipped with an internal thermostat that opens at 80°C (176°F) for optimum transmission operation and fuel economy. The transmission cooler pipe thermostat is part of the transmission fluid cooler pipe assembly, located near the transmission and is not serviced separately. From the cooler, the fluid returns through the transmission fluid cooler pipe assembly and enters the lubrication circuits. After lubricating the internal components, the fluid returns to the oil pan. The transmission fluid temperature (TFT) sensor is located in the control solenoid (w/body and TCM) valve assembly and is not serviced separately.

Conditions for Running the DTC

    â€¢ No OSS DTCs P0721, P0722, or P0723, P077B, P215C.
    â€¢ The engine run time is greater than 5 seconds.
    â€¢ The system voltage is 11-18 volts.
    â€¢ The estimated drive motor power loss is greater than 0.4 kw for 200 seconds.
    â€¢ The OSS is greater than 200 RPM for 5 seconds.

P0711

    â€¢ The TFT at start up is -50 to +21°C (-58 to +70°F) at start up.
    â€¢ The ECT is greater than 70°C (158°F).
    â€¢ The ECT is greater than 55°C (131°F) at start up.
    â€¢ The vehicle speed is greater than 8 km/h (5 mph) for 300 seconds.
    â€¢ The vehicle speed is less than 200 km/h (124 mph) for 5 seconds.
    â€¢ The TCM temperature is -49 to +169°C (-56 to +336°F).

P0712

DTC P0712 is not failed this ignition cycle.

P0713

DTC P0713 is not failed this ignition cycle.

Conditions for Setting the DTC

P0711 - Fail Case 1

    â€¢ Vehicle speed is greater than 8 km/h (5 mph) for 300 seconds cumulative.
    â€¢ The TFT is between -50 and +21°C (-58 and +70°F).
    â€¢ The TFT has changes by less than 2.0°C (3.6°F) in 100 seconds.
    â€¢ The engine coolant temperature (ECT) is greater than 70°C (158°F).
    â€¢ The ECT has increased by 55°C (99°F) since startup.

P0711 - Fail Case 2

    â€¢ The TFT is between 129-170°C (264-338°F).
    â€¢ The TFT has changed by less than 2.0°C (3.6°F) in 100 seconds.
    â€¢ The ECT is greater than 70°C (158°F).
    â€¢ The ECT has increased by 55°C (99°F) since startup.

P0711 - Fail Case 3

The TFT changes by greater than or equal to 20°C (36°F) 5 times over 7 seconds.

P0711 - Fail Case 4

    â€¢ The TFT start up temperature is -50°C (-58°F) and does not reach +20°C (+68°F) within 3200 seconds.
    â€¢ The TFT start up temperature is -25°C (-13°F) and does not reach +20°C (+68°F) within 2600 seconds.
    â€¢ The TFT start up temperature is -10°C (-14°F) and does not reach +20°C (+68°F) within 2000 seconds.
    â€¢ The TFT start up temperature is -5°C (-23°F) and does not reach +20°C (+68°F) within 1800 seconds.
    â€¢ The TFT start up temperature is 20°C (68°F) and does not reach +20°C (+68°F) within 300  seconds.

P0712

The TFT is greater than or equal to 160°C (320°F) for greater than 25 seconds.

P0713

The TFT is less than or equal to -60°C (-76°F) for greater than 10 seconds.

Action Taken When the DTC Sets

    â€¢ P0711 is a Type A DTC.
    â€¢ P0712 and P0713 are Type B DTCs.
    â€¢ The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

    â€¢ P0711 is a Type A DTC.
    â€¢ P0712 and P0713 are Type B DTCs.

Diagnostic Aids

The driver information center (DIC), if equipped, will display ‘TRANSMISSION HOT - Idle Engine’ when the TFT reaches 132°C (270°F). The TFT parameter on the scan tool should rise steadily to a normal operating temperature, and then stabilize. Ask about the customer’s driving habits, trailer towing, overloading, etc. Ensure the engine and transmission cooling system is functioning normally.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    â€¢  Circuit Testing
    â€¢  Connector Repairs
    â€¢  Testing for Intermittent Conditions and Poor Connections
    â€¢  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Special Tools

J 24731 Tempil Stick

Circuit/System Verification

Start the engine and operate the vehicle at 64 km/h (40 mph) while observing the TCM temperature sensor and the TFT sensor.

⇒The system is operating normally if the TCM temperature is within 10°C (18°F) of the TFT temperature.

Circuit/System Testing

  1. Inspect the transmission cooling system for restrictions or damage.
  2. ⇒If a concern is found, repair or replace the restricted or damaged components as necessary.
  3. Inspect the transmission cooler line thermostat for a stuck open or closed condition.
  4. ⇒If a concern is found repair or replace the damaged components as necessary.
  5. Clear the DTC and operate the vehicle under the conditions for running and setting the DTC. Verify that the DTC does not reset.
  6. ⇒If the DTC resets, replace the control solenoid (w/body and TCM) valve assembly.

Component Testing

    â€¢ Perform the Fluid Leak Diagnosis .
    â€¢ Perform the Transmission Fluid Check procedure.
    â€¢ Perform the Line Pressure Check procedure.
    â€¢ Perform the Main Fluid Pump Pressure High or Low procedure.
    â€¢ With a hand held infra red thermometer, or J 24731 test for the transmission cooler supply line thermostat for opening at 80°C (176°F). The transmission cooler supply line temperature should be higher on the transmission side of the thermostat than the cooler side until 80°C (176°F) is reached.
       â‡’If the thermostat tests stuck open or closed, replace the transmission cooler supply line assembly.

Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    â€¢  Transmission Fluid Cooler Pipe Replacement
    â€¢  Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.