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 D DTC.
Conditions for Running 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 at least 6 minutes and 49 seconds cumulative. |
| • | The TCC slip is greater than 120 RPM for at least 6 minutes and 49 seconds cumulative. |
| • | 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. |
Conditions for Setting the DTC
DTC P0711 sets when one of the following cases occurs:
Case 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.
Case 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 stores DTC P0711 in PCM history. |
Conditions for Clearing the DTC
| • | A scan tool clears the DTC from PCM history. |
| • | 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 wiring at the PCM, the transmission 20-way connector and all other circuit connecting points for the following conditions: |
| - | A backed out terminal |
| - | A damaged terminal |
| - | Reduced 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 engine wiring harness or the automatic transmission (A/T) wiring harness assembly.
-
This step determines if a condition exists with the PCM or TFT sensor.
-
Because of the harsh conditions inside the transmission, repairing the 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 | |||||
3 |
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) | ||||||
Important: Additional DTCs will set. 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 | |||||||
Important: Additional DTCs will set. Does the transmission fluid temperature change more than the specified value when the transmission 20-way connector is disconnected? | 1.5°C (2.7°F) | |||||||
7 | Inspect circuits 2762 (BLK) and 1227 (YEL/BLK) of the engine wiring harness for an intermittent open or short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||
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 | Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||
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 |
