Circuit Description
The Automatic Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermistor whose resistance value changes based on temperature. The PCM provides a 5 volt reference to the sensor on circuit 1227. A low fluid temperature or open circuits 1227 or 452 result in high signal voltage. The TFT operating range is -40 to +151°C (-40 to +305°F).
When the PCM detects a continuous open or a short to power on the TFT sensor circuit, then DTC P0713 sets. DTC P0713 is a Type D DTC.
Conditions for Setting the DTC
| • | No ECT DTCs P0117 or P0118 are set. |
| • | The PCM detects a reading of -40°C (-40°F) or less (5.04 volts or greater) for 6 seconds. |
| • | The vehicle speed is more than 16 km/h (10 mph) for 5 minutes. |
| • | The engine coolant is greater than -25°C (-13°F). |
Action Taken When the DTC Sets
| • | If any engine coolant temperature sensor codes set, the PCM substitutes a transmission fluid temperature default value of 132°C (269°F). |
| • | If the engine coolant temperature is greater than 110°C (230°F), the PCM substitutes a transmission fluid temperature default value of 132°C (269°F). This enables Transmission Hot Mode. The transmission remains in Hot Mode until the engine coolant temperature drops below 105°C (221°F). |
| • | If the engine run time is less than 5 minutes, the PCM substitutes the intake air temperature for the transmission fluid temperature value at ignition ON. |
| • | If the engine coolant temperature is 70-110°C (158-230°F), the transmission fluid default temperature equals ECT-10°C when the intake air temperature is less than 80°C (176°F) at ignition ON. If the intake air temperature is greater than 80°C (176°F) at ignition ON, the transmission fluid default temperature equals ECT+10°C. |
| • | If none of the above conditions exist, the PCM substitutes a transmission fluid temperature default value of 80°C (176°F). |
Conditions for Clearing the DTC
| • | 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
| • | Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Inspect the wiring for poor electrical connections at the Automatic Transmission Fluid Temperature sensor connector. Look for the following conditions: |
| - | A bent terminal |
| - | A backed out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| • | When diagnosing for an intermittent open condition, massage the wiring harness while watching the test equipment for a change. |
Test Description
The numbers below refer to the step numbers on the diagnostic chart.
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This Step ensures that you perform the Powertrain On-Board Diagnostic System Check.
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This Step ensures that the transmission fluid is at the proper level.
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If the display does not indicate an Automatic Transmission Fluid Temperature Sensor voltage greater than 4.98 volts, inspect the connectors and the terminal for intermittent conditions.
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Important: After 7 seconds, the scan tool will display a default temperature.
This Step isolates the Automatic Transmission Wiring Harness by using a fused jumper from terminal M to the transmission case. Inspect Engine Wiring Harness circuit 1227 and circuit 452 for an open. Use J 35616-A Test Connector Adapter Kit, so as not to damage the terminals.
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If the scan tool did not display a value of 4.98 volts or greater, inspect circuit 1227 of the engine harness for an open.
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If the scan tool did not display a value of 4.98 volts or greater, inspect circuit 452 of the engine harness for an open.
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If the scan tool did not display a value of 4.98 volts or greater, inspect circuit 452 of the Automatic Transmission Wiring Harness for an open. If you find an open, replace the transmission harness.
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This Step replaces the Automatic Transmission Fluid Temperature sensor after you find no open circuits in the Automatic Transmission Wiring Harness.
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This Step replaces the PCM after you inspect the circuitry and component.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to A Powertrain On Board Diagnostic (OBD) System Check | ||||||
Has the transmission fluid checking procedure been performed? | -- | Go to Transmission Fluid Check | ||||||
Important: Before clearing the DTCs, use the scan tool in order to record the Failure Records for reference. The Clear Info function will erase the data. Does the scan tool display an Automatic Transmission Fluid Temperature voltage equal to or greater than the specified value? | 4.98V | Go to Diagnostic Aids | ||||||
Does the scan tool display an Automatic Transmission Fluid Temperature voltage equal to or greater than the specified value? | 4.98V | |||||||
5 | Inspect circuit 1227 of the Engine Wiring Harness for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | ||||||
Inspect circuit 452 of the Engine Wiring Harness for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | |||||||
Inspect circuit 1227 and circuit 452 of the Automatic Transmission Wiring Harness for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | |||||||
Replace the Automatic Transmission Fluid Temperature sensor. Refer to Automatic Transmission Fluid Temperature Sensor Replacement in On-Vehicle Service. Is the replacement complete? | -- | -- | ||||||
Replace the PCM. Refer to PCM Replacement/Programming Section 6. Is the replacement complete? | -- | -- | ||||||
10 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
