Circuit Description
The automatic transmission fluid temperature (TFT) sensor is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The automatic 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 circuit. The circuit may be functional, but not in the normal operating range. This diagnostic indicates stuck, erratic, intermittent, skewed, or inaccurate values, indicating poor system performance. The TFT range is -40 to +151°C (-40 to +305°F).
If the transmission control module (TCM) detects rapid or no voltage changes in the TFT sensor circuit, then DTC P0711 sets. DTC P0711 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0711 Transmission Fluid Temperature (TFT) Sensor Performance
Conditions for Running the DTC
| • | No ECT DTC P0115. |
| • | DTC P0711 has not passed in the current ignition cycle. |
| • | No VSS DTCs P0722 or P0723. |
| • | The engine run time is greater than 5 seconds. |
| • | The transmission fluid temperature is -39°C to +149°C (-38°F to +300°F). |
| • | For conditions 1 and 2 below, the engine coolant temperature is greater than 70°C (158°F) and has changed by at least 50°C (90°F) since startup. |
| • | For conditions 1 and 2 below, the TCC slip speed is 120 RPM or greater for 500 seconds (8 minutes) cumulatively. |
Conditions for Setting the DTC
One of the following conditions occurs:
Condition 1
| • | The transmission fluid temperature at startup is -40 to +21°C (-40 to +70°F). |
| • | The vehicle speed is greater than 8 km/h (5 mph) for 750 seconds (12.5 minutes) cumulatively. |
| • | The transmission fluid temperature has not changed by more than 2°C (4°F) since startup for 100 seconds (1 minute and 40 seconds). |
Condition 2
| • | The transmission fluid temperature at startup is 129-150°C (264-302°F). |
| • | The vehicle speed is greater than 8 km/h (5 mph) for 750 seconds (8 minutes) cumulatively. |
| • | The transmission fluid temperature has not changed by more than 2°C (4°F) since startup for 100 seconds (1 minute and 40 seconds). |
Condition 3
The transmission fluid temperature has changed by 20°C (36°F) 14 times within 7 seconds.
Action Taken When the DTC Sets
| • | The TCM does not request the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL). |
| • | The TCM commands elevated line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | The TCM stores DTC P0711 in TCM history. |
Conditions for Clearing the DTC
| • | A scan tool can clear the DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for an intermittent short or open condition in the engine wiring harness. The test lamp is used as a resistor in the circuit.
-
This step determines if the TCM or the TFT sensor is causing a steady, unchanging TFT reading.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||
2 | Inspect for correct transmission fluid level. Refer to Transmission Fluid Check . Did you perform the fluid checking procedure? | -- | Go to Step 3 | Go to Transmission Fluid Check | ||||
3 |
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the TCM.
Did either of the conditions occur? | -- | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | ||||
4 | Did the scan tool display a condition in which the Trans. Fluid Temp. does not change by more than the specified value in 300 seconds since startup? | 2°C (36°F) | Go to Step 6 | Go to Step 5 | ||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Does the scan tool Trans. Fluid Temp. change by more than the specified value? | 20°C (68°F) | Go to Step 7 | Go to Step 8 | |||||
Does the scan tool display the same condition as in Step 4? | -- | Go to Step 11 | Go to Step 10 | |||||
7 |
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 | ||||
8 |
Refer to Circuit Testing . Did you find an intermittent open or short condition? | -- | Go to Step 9 | Go to Step 10 | ||||
9 | Replace the AT wiring harness. Did you complete the replacement? | -- | Go to Step 12 | -- | ||||
10 | Replace the TFT sensor, this sensor is part of the TFP manual valve position switch. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||
11 | Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | -- | ||||
12 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 13 | Go to Step 2 | ||||
13 | With the scan tool, observe the stored information, capture info, and DTC Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
