DTC P0711 TFT Sensor Circuit Range/Performance 3.8L, VIN K Only
Circuit Description
The Automatic Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermister within the Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch. The TFT sensor controls the signal voltage from the PCM. The PCM supplies a 5 volt reference signal to the sensor on circuit 1227. When the transmission fluid is cold, the sensor resistance is high, and the PCM detects high signal voltage. As the transmission fluid temperature increases, the sensor resistance decreases and the detected voltage decreases. At the transmission's normal TFT operating temperature, 100°C (212°F), the voltage is approximately 1.5-2 volts.
If the PCM detects an unrealistically large change in the transmission fluid temperature for two consecutive ignition cycles, then DTC P0711 sets. If the PCM detects a TFT value which remains constant for a period of time in which a measurable amount of change is expected for two consecutive ignition cycles, then DTC P0711 sets. DTC P0711 is a type B DTC.
Conditions for Setting the DTC
| • | The system voltage is 10-16 volts. |
| • | No VSS DTCs P0502 or P0503. |
| • | The Transmission Fluid Temperature sensor voltage is 0.2-4.92 volts. |
| • | No Transmission Component Slipping DTC P1870. |
| • | The engine run time is 409 seconds or more. |
| • | The vehicle speed is equal to or greater than 8 km/h (5 mph) for 409 seconds or more within a single ignition cycle. |
| • | The TCC slip speed is equal to or greater than 120 RPM for 409 seconds or more within a single ignition cycle. |
| • | The Transmission Fluid Temperature at start up is -40 to +21°C (-40 to +70°F). |
| • | The Transmission Fluid Temperature is equal to or greater than 70°C (158°F) and has changed by at least 50°C (90°F) since start up. |
All the above conditions are met and either of the following Cases occurs in two consecutive ignition cycles:
Case 1
| • | The Transmission Fluid Temperature has changed by less than 1.5°C (2.7°F) since start up. |
| • | Case 1 is met for 409 seconds or more. |
Case 2
| • | The Transmission Fluid Temperature has changed by 20°C (36°F) or more within 0.2 seconds. |
| • | Case 2 is met 14 times or more within 7 seconds. |
Action Taken When the DTC Sets
| • | The PCM freezes shift adapts from being updated. |
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
| • | The PCM determines a default Transmission Fluid Temperature (TFT) using the following matrix: |
| - | If any Engine Coolant Temperature (ECT) DTCs P0117, P0118, or P1114, or P1115 are set, then the default TFT is equal to 135°C (275°F). |
| - | If the ECT is 125°C (257°F) or more, then the default TFT is equal to 135°C (275°F). |
| - | If the Engine Run Time is less than 300 seconds, and: |
| • | No Intake Air Temperature (IAT) DTCs P0112 or P0113 are set, and the IAT is available, then the default TFT is equal to the IAT. |
| • | Any Intake Air Temperature (IAT) DTCs P0112 or P0113 are set, or the IAT is not available, then the default TFT is equal to 90°C (194°F). |
| - | If the Engine Run Time is greater than 300 seconds, and no Intake Air Temperature (IAT) DTCs P0112 or P0113 are set, and the IAT is available, and the Engine Coolant Temperature (ECT) is 40-125°C (104-257°F) and: |
| • | IAT at start up is less than 15°C (59°F), then the default TFT is equal to the Engine Coolant Temperature (ECT) plus 5°C (8°F). |
| • | IAT at start up is greater than 35°C (95°F), then the default TFT is equal to teh Engine Coolant Temperature (ECT) plus 10°C (16°F). |
| • | IAT at start up is 15-35°C (59-95°F), then the default TFT is equal to the Engine Coolant Temperature (ECT). |
| - | If the Engine Run Time is greater than 300 seconds, and any Intake Air Temperature DTCs P0112 or P0113 are set, or the IAT is not available then the default TFT is equal to the Engine Coolant Temperature (ECT). |
| - | If the Engine Run Time is greater than 300 seconds, and the ECT is less than 40°C (104°F) or more, then the default TFT is equal to 60°C (140°F). |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after completing three consecutive ignition cycles without a reported failure. |
| • | A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if 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
| • | If a transmission fluid overtemperature DTC P0218 is also set, inspect the transmission cooling system for blockage and restrictions. |
| • | Inspect the harness routing for an intermittent short to ground in circuit 1227. The scan tool TFT display should rise steadily to about 100°C (212°F), then stabilize. |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for changes. |
| • | Inspect the wiring for poor electrical connections at the PCM. Look for the following problems: |
| - | A bent terminal |
| - | A backed out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| • | Use the Temperature vs Resistance scale in order to test the TFT sensor at various temperatures. Test the TFT sensor in order to eliminate the possibility of a skewed (mis-scaled) sensor. A skewed sensor could cause delayed garage shifts or TCC complaints. |
| • | Inquire about the customer's driving habits, trailer towing, etc... |
Test Description
An example test description follows:
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 , Section 6. | |||||||||||||
2 | Inspect the Automatic Transmission Fluid. Refer to Transmission Fluid Check . Did you perform the fluid checking procedure? | -- | Go to Transmission Fluid Check . | |||||||||||||
3 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. does the scan tool display a TFT Sensor Voltage less than the specified value? | 0.2 volts | ||||||||||||||
4 |
Does the TFT Sensor voltage change to greater than the specified value? | 4.92 Volts | ||||||||||||||
5 |
Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | ||||||||||||||
6 | Does the scan tool display a TFT Sensor voltage greater than the specified value? | 4.92 Volts | ||||||||||||||
7 |
Does the TFT Sensor voltage change to less than the specified value? | 0.2 Volts | ||||||||||||||
8 | Inspect circuit 1227 (YEL/BLK) for an open or a short to Battery Positive Voltage. Refer to Troubleshooting Procedures, Section 8. Did you find and correct a problem? | -- | ||||||||||||||
Does the scan tool display the TFT and the correct corresponding TFT Sensor voltage, as specified in the Temperature vs Resistance table, for the entire warm-up period? | -- | |||||||||||||||
10 |
Important: Perform the following inspections between the Transmission Fluid Temperature (TFT) Sensor and the transmission 20-way connector. The TFT Sensor is part of the Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch.
Did you find and correct a problem? | -- | ||||||||||||||
11 | Replace the Automatic Transmission Fluid Pressure (TFP) Manual Valve Position Switch. Refer to Control Valve Body and Pressure Switch, in On-Vehicle Service. Is the replacement complete? | -- | -- | |||||||||||||
12 | Inspect the PCM connector terminals for the following problems:
Did you find and correct a problem? | -- | ||||||||||||||
13 | Replace the Powertrain Control Module (PCM). Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | ||||||||||||||
14 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
