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).
If 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 Running the DTC
| • | The engine run time is greater than 5 minutes. |
| • | The vehicle speed is greater than 16 km/h (10 mph) for 5 minutes. |
| • | The engine coolant temperature is greater than -25°C (-13°F). |
Conditions for Setting the DTC
The PCM detects a reading of -40°C (-40°F) or less (5.04 volts or greater) for 6 seconds.
Action Taken When the DTC Sets
| • | The PCM does not illuminate the malfunction indicator lamp (MIL). |
| • | The PCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time. |
| • | The PCM stores DTC P0713 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 the TFT sensor 2-way connector 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 |
| • | When diagnosing for an intermittent open, 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 table.
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If the display does not indicate a TFT 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 the engine wiring harness circuit 1227 and circuit 452 for an open.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
2 | Was the Transmission Fluid Checking Procedure performed? | -- | Go to Transmission Fluid Check | |||||||
Important: Before clearing the DTCs, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the PCM. Does the scan tool display a TFT sensor voltage equal to or greater than the specified value? | 4.98V | Go to Diagnostic Aids | ||||||||
Does the scan tool display a TFT sensor 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 General Electrical Diagnosis in Wiring Systems. Was the condition found? | -- | ||||||||
6 | Inspect circuit 452 of the engine wiring harness for an open. Refer to General Electrical Diagnosis in Wiring Systems. Was the condition found? | -- | ||||||||
7 |
Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||||
8 | Repair the wiring as necessary. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||||
9 | Replace the automatic transmission wiring harness. Refer to Unit Repair. Is the replacement complete? | -- | -- | |||||||
10 | Replace the TFT sensor. Refer to Unit Repair. Is the replacement complete? | -- | -- | |||||||
11 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||||
12 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
