Circuit Description
The Automatic Transmission Fluid Temperature (TFT) sensor is a thermistor within the Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.). The TFT sensor controls the signal voltage to the VCM. The VCM supplies a 5-volt reference signal to the sensor on circuit 1227. When the transmission fluid is cold, the sensor resistance is high. The VCM detects high signal voltage. As the transmission fluid temperature increases to the normal operating temperature, the sensor resistance becomes less and the voltage decreases.
When the VCM detects one of the following unusual conditions, then DTC P0711 sets.
| • | An unrealistically large change in transmission temperature |
| • | A value which remains constant for a period of time in which a measurable amount of change is expected |
DTC P0711 is a type B DTC.
Conditions for Setting the DTC
DTC P0711 sets if the following conditions occur two consecutive times:
| • | No VSS Assy. DTC P0502. |
| • | No Transmission Component Slipping DTC P1870. |
| • | The system voltage is 10-19 volts. |
| • | The engine is running for 409 seconds. |
| • | The vehicle speed is greater than 8 km/h (5 mph) for 409 seconds. |
| • | The TCC slip speed is greater than 120 RPM for 409 seconds. |
| • | The transmission fluid temperature at startup is between -40 and +21°C (-40 and +70°F). |
| • | The TFT is between -38 and +151°C (-36 and +304°F). |
| • | The engine coolant temperature is greater than 70°C (158°F) and the temperature has changed by 50°C (90°F) since startup. |
| • | All of the above conditions are met and either of the following fail conditions occurs: |
| - | The transmission fluid temperature does not change more than 1.50°C (2.7°F) for 409 seconds since startup. |
| - | The transmission fluid temperature changes more than 20°C (36°F) in 200 milliseconds 14 times within 7 seconds. |
Action Taken When the DTC Sets
| • | The VCM uses a transmission fluid temperature default value of 135°C (275°F). |
| • | The VCM freezes shift adapts from being updated. |
| • | The VCM illuminates the Malfunction Indicator Lamp (MIL). |
Conditions for Clearing the MIL/DTC
| • | The VCM turns OFF the MIL after three consecutive ignition cycles without a failure reported. |
| • | A scan tool can clear the DTC from the VCM history. The VCM clears the DTC from the VCM history if the vehicle completes 40 warm-up cycles without a failure reported. |
| • | The VCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the VCM. |
Diagnostic Aids
DTC P0218 will set approximately 409 seconds after DTC P0711 has set. Follow the diagnostic chart for DTC P0711 before proceeding to the diagnostic chart for DTC P0218. Repairing the condition that caused DTC P 0711 will likely eliminate DTC P0218.
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 light is used as a resistor in the circuit.
-
This step determines if the VCM or the TFT sensor is causing a steady, unchanging TFT reading.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||
2 | Perform the transmission fluid checking procedure. 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 the Failure Records for reference. The Clear Info function will erase the data.
Did either of the fail conditions occur? | -- | Go to Diagnostic Aids | |||||
4 | Did the scan tool display a condition in which the TFT does not change by more than the specified value in 409 seconds since startup? | 1.50°C (2.7°F) | ||||||
Does the TFT change by more than the specified value? | 20°C (36°F) | |||||||
6 |
Does the scan tool display the same condition as in Step 4? | -- | ||||||
7 |
Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||||||
8 |
Refer to Electrical Diagnosis. Section 8. Did you find a problem? | -- | ||||||
9 | Replace the Automatic Transmission Wiring Harness Assembly. Refer to On-Vehicle Service. Is the replacement complete? | -- | -- | |||||
10 | Replace the TFT Sensor (the sensor is a part of the TFP Valve Position Switch). Refer to Valve Body, in On-Vehicle Service. Is the replacement complete? | -- | -- | |||||
11 | Replace the VCM. Refer to VCM Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |||||
12 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
