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, the sensor resistance decreases. The TFT range is -40 to +150°C (-40 to +302°F).

The PCM provides a 5 volt reference through a fixed series resistor, to the TFT circuit and monitors the voltage after the resistor, as the voltage drop (signal) across the circuit.

If the PCM detects a large, rapid, fluid temperature change, or essentially, no change from a cold start up, then DTC P0711 sets. DTC P0711 is a type D DTC.

CONDITIONS FOR SETTING THE DTC
- No VSS DTCs P0502 or P0503.
- System voltage is 10-16 volts.
- No Transmission Component Slipping DTC P1870.
- The TFT at start up is -40 to 21°C (-40 to 69°F).
- The engine run time is 5 minutes or more.
- The vehicle speed is 8 km/h (5 mph) or more for 7 minutes or more, cumulative this ignition cycle.
- The TCC slip speed is 120 RPM or more for 7 minutes, cumulative this ignition cycle.
- The ECT is 70°C (158°F) or more.
- The ECT has changed 50°C (90°F) or more since start up.
- The TFT voltage is 0.20-4.92 volts. All of the above must be true and one of the following fail cases must be true:
- Fail Case 1
The change in TFT is 1.5°C (2.7°F) or less since start up for 7 minutes or more.
- Fail Case 2
The change in TFT is 20°C (36°F) or more within 0.2 seconds for 14 times or more within 7 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The PCM does not illuminate the Malfunction Indicator Lamp (MIL).
- The PCM calculates a transmission fluid default temperature as follows:
- If the Engine Run Time is less than 3 minutes and:
- The Intake Air Temperature (IAT) DTC(s) P0112, P0113, P1111 or P1112 is set, then the default Automatic Transmission Fluid Temperature (TFT) is set to 0°C (32°F).
- No IAT DTC is set, then the default TFT is set to the IAT value which was saved at start up.
- If the engine run time is greater than 3 minutes and:
- The Engine Coolant Temperature (ECT) DTC(s) P0117, P0118, P1114 or P1115 is set, then the default TFT is set to 131°C (268°F).
- No ECT DTC is set, and:
- The ECT is less than 45°C (113°F), then the default TFT is 12°C (54°F).
- The ECT is greater than 115°C (239°F), then the default TFT is 131°C (268°F).
- No ECT DTC is set, the ECT is 45-115°C (113-239°F) and:
- The IAT DTC(s) P0112, P0113, P1111 or P1112 is set, then the default TFT is set to equal the ECT.
- The IAT at start up is less than 0°C (32°F), then the default TFT is set to the ECT value minus 10°C (18°F).
- The IAT at start up is greater than 28°C (82°F), then the default TFT is set to the ECT value plus 10°C (18°F).
- The IAT at start up is 0-28°C (32-82°F), then the default TFT is set to equal the ECT value.

CONDITIONS FOR CLEARING THE DTC
- A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history it the vehicle completes 40 warm-up cycles without a failure reported.
- The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

DIAGNOSTIC AIDS
- Inspect the wiring at the PCM the transmission 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 in order to evaluate the possibility of a skewed (mis-scaled) sensor.
Refer to Temperature vs Resistance.
- When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for proper A/T fluid level and condition.
3. This step verifies which condition has set DTC P0711.
5. The 12-volt test lamp is used as a fixed resistance.
6. This step ensures that the VCM monitors circuit 1227.