P0711

Circuit Description
The automatic transmission fluid temperature (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 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 range is -40 to +151°C (-40 to +304°F). If the Powertrain Control Module (PCM) detects an intermittent voltage or no voltage change in the TFT sensor circuit, then DTC P0711 sets. DTC P0711 is a Type D DTC.

Conditions for Setting the DTC
^ No Vehicle Speed Sensor (VSS) DTCs P0502 or P0503 are set.
^ The system voltage is 9-18 volts.
^ The TFT sensor voltage is 0.2-4.92 volts.
^ The transmission fluid temperature at start-up is -40 to 21°C (-40 to 69°F).
^ The engine run time is more than 5 minutes.
^ The vehicle speed is greater than 8 km/h (5 mph) for greater than 409 seconds cumulative.
^ The TCC slip is greater than 120 RPM for 7 minutes cumulative.
^ The engine coolant temperature is more than 70°C (158°F).
^ The engine coolant temperature has changed by 50° (90°F) since start-up.

Fail case 1
The change in transmission fluid temperature is less than 1.5°C (2°F) since start-up for 7 minutes continuous.

Fail case 2
The change in transmission fluid temperature is greater than 20°c (36°F) within 0.2 seconds and 14 times within 7 seconds.

Action Taken When the DTC Sets
^ The PCM does not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM freezes shift adapts.
^ The PCM calculates a default TFT from the engine coolant temperature (ECT) sensor and the intake air temperature (IAT) sensor.
^ The PCM stores DTC P0711 in PCM history.

Conditions for Clearing the MIL/DTC
^ A scan tool clears the DTC from the PCM history.
^ The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ Inspect the wiring at the PCM, the transmission 20-way connector and all other circuit connecting points for the following conditions:
- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
^ Test the TFT sensor at various temperature levels to evaluate the possibility of a skewed (mis-scaled) sensor. Refer to the Temperature vs Resistance table. Electrical Specifications
^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
^ Inspect the transmission 20-way connector for transmission fluid.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step determines if the condition exists in the wiring or a component.
5. This step determines if the condition exists in the engine harness or the transmission harness.
6. This step determines if a condition exists with the PCM or TFT Sensor.
9. Because of the harsh conditions inside the transmission, repairing the automatic transmission wiring harness assembly (A/T Wiring Harness Assembly) is not acceptable. It must be replaced if it is damaged in any way.