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 sensor 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 C DTC.
Conditions for Running the DTC
| • | No VSS DTC P0502 or P0503. |
| • | The system voltage is 9-18 volts. |
| • | The engine coolant temperature is 70°C (158°F) or more. |
| • | The engine coolant temperature has changed by 50°C (90°F) or more since start-up. |
| • | The engine run time is more than 5 minutes. |
| • | 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 vehicle speed is greater than 8 km/h (5 mph) for at least 6 minutes and 49 seconds cumulative. |
| • | The TCC slip is greater than 80 RPM for at least 6 minutes and 49 seconds cumulative. |
Conditions for Setting the DTC
DTC P0711 sets when one of the following conditions occurs:
Condition 1
The change in transmission fluid temperature is less than 1.5°C (2°F) since start-up for at least 6 minutes and 49 seconds continuous.
Condition 2
The change in transmission fluid temperature is greater than 20°C (36°F) within 0.2 seconds and this occurs at least 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 ECT sensor and the IAT sensor. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records. |
| • | The PCM stores DTC P0711 in PCM history. |
Conditions for Clearing the DTC
| • | A scan tool can clear the DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 consecutive warm-up cycles without a non-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 connectors at the controller, the component and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents in Wiring Systems. |
| • | Test the TFT sensor at various temperature levels to evaluate the possibility of a skewed (mis-scaled) sensor. Refer to the Transmission Fluid Temperature Sensor Specifications table. |
| • | 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 attempts to repeat the condition that set the DTC.
-
This step attempts to repeat the condition in the engine wiring harness.
-
This step determines if a condition exists with the PCM or TFT sensor.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls | |||||
2 | Did you perform the transmission fluid checking procedure? | -- | 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. Did you record the temperatures? | -- | -- | ||||||
4 | Does the TFT rise more than the specified value? | 1.5°C (2.7°F) | ||||||
Refer to Automatic Transmission Inline Harness Connector End View . Does the transmission fluid temperature change by more than the specified value? | 20°C (36°F) in 0.20 seconds | |||||||
Does the transmission fluid temperature change more than the specified value when the AT inline 20-way connector is disconnected? | 1.5°C (2.7°F) | |||||||
7 |
Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution. Test the signal circuit (CKT 1227) of the TFT sensor for an intermittent open or short to ground between the PCM and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||
8 | Test the ground circuit (CKT 2762) of the TFT sensor for an intermittent open or short to ground between the PCM and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||
9 | Test the signal circuit (CKT 1227) of the TFT sensor for an intermittent open or short to ground between the AT inline 20-way connector and the TFT sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find the condition? | -- | ||||||
10 | Test the ground circuit (CKT 452) of the TFT sensor for an intermittent open or short to ground between the AT inline 20-way connector and the TFT sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find the condition? | -- | ||||||
11 | Replace the Automatic Transmission Wiring Harness Assembly. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | -- | |||||
12 | Replace the TFT sensor. Refer to Fluid Temperature Sensor Replacement . Did you complete the replacement? | -- | -- | |||||
13 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Did you complete the replacement? | -- | -- | |||||
14 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
