The automatic transmission fluid temperature (TFT) sensor is part of the 4L80-E automatic transmission (AT) wiring harness assembly. The TFT sensor is a resistor, or thermistor, which changes value based on temperature. The sensor has a negative temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases the resistance increases. The powertrain control module (PCM) supplies a 5-volt reference signal to the sensor and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the PCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. The PCM uses this information to control shift quality and torque converter clutch (TCC) apply.
If the PCM detects a continuous open or short to voltage in the TFT signal circuit or the TFT sensor, then DTC P0713 sets. DTC P0713 is a type C DTC.
This diagnostic procedure supports the following DTC:
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Voltage
• | No TFT sensor DTC P0712. |
• | System voltage is 8-18 volts. |
• | The engine is running for greater than 7 seconds. |
The TFT sensor indicates a voltage greater than 4.94 volts for 407 seconds (6.8 minutes).
• | The PCM does not illuminate the malfunction indicator lamp (MIL). |
• | The PCM commands increased line pressure. |
• | The PCM freezes transmission adaptive functions. |
• | The PCM determines a default TFT using the following matrix: |
- | If the engine run time is less than 60 seconds then default TFT equals 47°C (117°F). |
- | If ECT is less than 20°C (68°F), then default TFT equals IAT. |
- | If the ECT is 20-110°C (68-230°F) then default TFT equals ECT. |
- | If the ECT is greater than 110°C (230°F) then default TFT is set to 140°C (284°F) and transmission shift pattern is in hot mode. |
- | If ECT and TFT DTCs are both set then default TFT is 140°C (284°F). |
• | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records. |
• | The PCM stores DTC P0713 in PCM history. |
• | A scan tool clears the DTC from PCM history. |
• | The PCM clears the DTC from PCM history if the vehicle completes 40 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. |
DTC P0713 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.
The numbers below refer to the step numbers on the diagnostic table.
This step verifies a condition in the TFT sensor circuit inside the transmission.
This step tests for higher than normal circuit voltage which may also damage the TFT sensor.
Step | Action | Value | 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 PCM. Does the scan tool display a TFT Sensor signal voltage less than the specified value? | 4.92 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
4 |
Does the TFT Sensor signal voltage drop to less than the specified value? | 0.2 V | Go to Step 5 | Go to Step 6 |
Does the resistance measure within the specified range? | 3,088-3,942 ohms at 20°C (68°F) 159-198 ohms at 100°C (212°F) | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 8 | |
Test the signal circuit of the TFT sensor an open or short to voltage between the PCM connector C2 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 | |
7 | Test the low reference circuit of the TFT sensor for an open. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
8 | Replace the AT wiring harness assembly. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
9 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 10 | -- |
10 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 11 | Go to Step 2 |
11 | 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 |
The automatic transmission fluid temperature (TFT) sensor is part of the 4L80-E automatic transmission (AT) wiring harness assembly. The TFT sensor is a resistor, or thermistor, which changes value based on temperature. The sensor has a negative temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases the resistance increases. The transmission control module (TCM) supplies a 5-volt reference signal to the sensor and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the TCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. The TCM uses this information to control shift quality and torque converter clutch (TCC) apply.
If the TCM detects a continuous open or short to voltage in the TFT signal circuit or the TFT sensor, then DTC P0713 sets. DTC P0713 is a type C DTC.
This diagnostic procedure supports the following DTC:
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Voltage
• | No ISS DTCs P0716 or P0717. |
• | No OSS DTCs P0722 or P0723. |
• | System voltage is 8-18 volts. |
• | The engine is running for greater than 5 seconds. |
• | The transmission OSS is 200 RPM or greater for 200 seconds (3 minutes) or greater. |
• | The TCC slip speed is 120 RPM or greater for 200 seconds (3 minutes) or greater. |
The TFT sensor indicates a temperature of -40°C (-40°F) or less for 80 seconds (1 minute).
• | The TCM does not request the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL). |
• | The TCM commands increased line pressure. |
• | The TCM freezes transmission adaptive functions. |
• | The TCM determines a default TFT using the following matrix: |
- | If the engine run time is less than 60 seconds then default TFT equals 47°C (117°F). |
- | If ECT is less than 20°C (68°F), then default TFT equals IAT. |
- | If the ECT is 20-110°C (68-230°F) then default TFT equals ECT. |
- | If ECT and TFT DTCs are both set then default TFT is 140°C (284°F). |
• | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records. |
• | The TCM stores DTC P0713 in TCM history. |
• | A scan tool clears the DTC from TCM history. |
• | 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. |
DTC P0713 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.
The numbers below refer to the step numbers on the diagnostic table.
A value of 4.9-5.0 volts indicates the TCM and engine side of the wiring are good.
A short to voltage greater than 5 volts would cause the TFT sensor to open.
A short to the TFT sensor signal circuit and any other circuits in the transmission harness could cause the TFT sensor to open.
Step | Action | Value | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||
2 |
Important: Before clearing the DTCs, use the scan tool in order to record the ECM and TCM Failure Records for reference. Using the Clear Info function will erase the stored Failure Records from the ECM and TCM. Does the scan tool display a TFT greater than the specified value? | -40°C (-40°F) | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||
Does the voltage measure within the specified range? | 4.9-5.0 V | Go to Step 7 | Go to Step 4 | |||||
4 | Does the voltage in Step 3 measure greater than the specified value? | 5.0 V | Go to Step 6 | Go to Step 5 | ||||
5 |
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 | ||||
Test the signal circuit of the TFT sensor a short to voltage between the TCM and the AT inline 20-way connector. Refer to Testing for a Short to Voltage and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 13 | |||||
7 |
Is the resistance less than the specified value? | 100 K ohms | Go to Step 9 | Go to Step 8 | ||||
8 |
Did you find the condition? | -- | Go to Step 10 | Go to Step 12 | ||||
Measure the resistance between the TFT sensor signal and all other terminals, except the TFT sensor low reference, of the J 44152 . Is the resistance greater than the specified value? | 1,000 ohms | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 10 | |||||
10 | Replace the automatic transmission wiring harness assembly. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- | ||||
11 | Was the engine harness repaired, or the transmission harness replaced due to a short to power or other circuit? | -- | Go to Step 12 | Go to Step 14 | ||||
12 | Replace the automatic transmission fluid temperature sensor. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||
13 | Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||
14 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 15 | Go to Step 2 | ||||
15 | 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 |