Diagnostic Instructions

DTC Descriptor

DTC P0711:  Transmission Fluid Temperature (TFT) Sensor Performance

Diagnostic Fault Information

Circuit	Signal Performance
TFT Sensor Signal	P0218, P0711
Low Reference	P0218, P0711

Typical Scan Tool Data

Transmission Fluid Temperature

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Engine running in PARK, normal operating temperature Parameter Normal Range: Varies near coolant temperature
Trans. Fluid Temp.	150°C (304°F)	-40°C (-40°F)	-40°C (-40°F)

Circuit/System Description

The automatic transmission fluid temperature (TFT) sensor is a negative coefficient thermistor. The TFT sensor is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The transmission control module (TCM) supplies a 5-volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the TCM senses a high signal voltage. As the transmission fluid warms up, the sensor resistance decreases and the TCM senses lower voltage. The TCM uses the TFT reading in order to control the torque converter clutch (TCC), line pressure adjustments, and temperature compensated shifts. This diagnostic monitors the TFT sensor circuit. The circuit may be functional but not in the normal operating range. This diagnostic indicates stuck, erratic, intermittent, or skewed values, resulting in reduced system performance. The TFT sensor range is -40 to +150°C (-40 to +304°F).

Conditions for Running the DTC

Fail Case 1

OR

Fail Case 2

OR

Fail Case  3

Conditions for Setting the DTC

Fail Case 1

OR

Fail Case 2

OR

Fail Case 3

The change in TFT is 20°C (68°F) or less after a predetermined time.

Action Taken When the DTC Sets

Conditions for Clearing the DTC

DTC P0711 is a type C DTC.

Diagnostic Aids

DTC P0711 detects a TFT that remains constant for a period of time in which a measurable amount of change is expected or a TFT in which large rapid unrealistic changes occur in a very short period of time.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Special Tools

Circuit/System Verification

1. Operate the vehicle at 64 km/h (40 mph) for at least 300 seconds (5 minutes) while observing the Trans. Fluid Temp. parameter on the scan tool. The Trans. Fluid Temp. parameter should rise by 2°C (3°F) or greater. When at normal operating temperature, the Trans. Fluid Temp. parameter on the scan tool should display near the ECT sensor parameter.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, using the remover J 44257 , disconnect the automatic transmission inline 20-way connector and install the jumper harness J 44152 on the engine side of the AT inline 20-way connector X175.
2. Ignition ON, engine OFF. Observe the Trans. Fluid Temp. parameter on the scan tool. The Trans. Fluid Temp. should display -40°C (-40°F). If the Trans. Fluid Temp. is -40°C (-40°F), the TFT is stuck, replace the TFT sensor.

Important: When test probing TCM harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 GM terminal test kit. Use of the brown J 35616-6 (1.00 mm) PCM probe in a 0.64 mm terminal will deform the terminal, resulting in intermittent open conditions. The correct probe for TCM harnesses is the light blue J 35616-64B (0.64 mm) probe.

3. Ignition ON, using the light blue probes J 35616-64B, test for 4.9-5.1 V between the TFT Sensor signal circuit jumper harness pin L and a good ground.

⇒	If the voltage is less than the specified range, test the TFT sensor signal circuit for an open, high resistance or short to ground.

Important: If a short to voltage is found, test the TFT sensor for damage.

⇒	If the voltage is greater than the specified range, test the TFT sensor signal circuit for a short to voltage.

4. Using the light blue probes J 35616-64B, test for 4.9-5.1 V between the TFT Sensor signal circuit jumper harness pin L and the TFT low reference circuit jumper harness pin M.

⇒	If the voltage is less than the specified value, test the low reference circuit for an open, high resistance.

5. Remove the jumper harness J 44152 from the engine side of the AT inline 20-way connector and install it on the transmission pass-thru connector.
6. Using the light-blue test probes J 35616-65B from the most current J 35616 GM terminal test kit, test for 3164-3867 Ω at 20°C (68°F) between the TFT Sensor signal circuit jumper harness pin L and the TFT low reference circuit jumper harness pin M. Refer to Transmission Fluid Temperature Sensor Specifications for the resistance at other temperatures.

⇒	If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, replace the TFT sensor.

⇒	If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the TFT sensor.

7. Test for greater than 10K Ω between the TFT Sensor signal circuit jumper harness pin L and all other circuits of the jumper harness J 44152 , except the TFT low reference circuit jumper harness pin M.

⇒	If less than the specified range, the affected circuits are shorted together. Replace the transmission internal wire harness.

8. Test for greater than 10M Ω from the TFT Sensor signal circuit jumper harness pin L and the TFT low reference circuit jumper harness pin M to the transmission case.

⇒	If less than the specified value, the affected circuit is shorted to the transmission case. Replace the transmission internal wire harness.

9. If all circuits and connections test normal, replace the TCM.

Component Testing

1. Ignition OFF, using the remover J 44257 disconnect the automatic transmission inline 20-way connector and install the jumper harness J 44152 on the transmission pass-thru connector.
2. Using the light-blue test probes J 35616-65B, test for 3164-3867 Ω at 20°C (68°F) between the TFT Sensor signal circuit jumper harness pin L and the TFT low reference circuit jumper harness pin M. Refer to Transmission Fluid Temperature Sensor Specifications for the resistance at other temperatures.

⇒	If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, test the engine side of the TFT Sensor signal circuit for a short to voltage AND replace the TFT sensor.

⇒	If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the TFT sensor.

3. Test the TCM for supplying a 5-volt reference, 4.9-5.1 V, to the TFT sensor signal circuit jumper harness pin L.

⇒	If the TCM is not supplying a 5-volt reference to the TFT sensor, replace the TCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.