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 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 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°C (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
| • | The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | 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. |
| • | 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.
-
This step determines if the condition exists in the wiring or a component.
-
This step determines if the condition exists in the engine harness or the transmission harness.
-
This step determines if a condition exists with the PCM or TFT Sensor.
-
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.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls | |||||||
2 | Was the transmission fluid checking procedure performed? | -- | Go to Transmission Fluid Check | |||||||
Important: Before clearing the DTCs, use the Scan Tool in order to record the Failure Records for reference. Using the Clear Info function will erase the stored Failure Records from the PCM. Does the transmission fluid temperature change by more than the specified value? | 20° in 0.20 seconds | |||||||||
4 | Run the vehicle for at least 7 minutes. Does the TFT rise more than the specified value? | 1.5°C (2.7°F) | Go to Diagnostic Aids | |||||||
Important: Additional DTCs will set. Does the TFT change by more than the specified value? | 20°C (36°F) in 0.20 seconds | |||||||||
Important: Additional DTCs will set. Is the TFT the same as in step 3? | -- | |||||||||
7 |
Refer to General Electrical Diagnosis in Wiring Systems. Was the condition found and corrected? | -- | ||||||||
8 | Inspect circuits 452 (GRY) and 1227 (BRN) of the automatic transmission wiring harness assembly for an intermittent open or short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||||
Replace the Automatic Transmission Wiring Harness Assembly. Refer to Solenoids and Wiring Harness Replacement . Is the replacement complete? | -- | -- | ||||||||
10 | Inspect PCM connector C2 for bent, damaged or backed out connector pins. Was a condition found and corrected? | -- | ||||||||
11 | Replace the TFT sensor. Refer to Fluid Temperature Sensor Replacement . Is the replacement complete? | -- | -- | |||||||
12 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
