The P0713 code is a generic OBD-II diagnostic trouble code indicating “Transmission Fluid Temperature Sensor ‘A’ Circuit High.” It means the control module detected an abnormally high voltage in the transmission fluid temperature sensor circuit.
This code does not automatically prove the sensor has failed. Diagnosis requires checking the wiring for opens or shorts and testing the sensor resistance before replacing any components.
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Key Takeaways
- The P0713 code indicates the control module detected a high voltage condition or open circuit in the primary transmission fluid temperature sensor circuit.
- Possible causes include a failed transmission fluid temperature sensor, damaged wiring, corroded connectors, or an open circuit in the harness.
- Diagnosis involves inspecting the transmission harness, checking for pinched wires, and measuring the sensor’s internal resistance.
- Repairs may involve repairing the wiring harness, cleaning connectors, or replacing the confirmed failed transmission fluid temperature sensor.
P0713 Code Description and Implications
The P0713 code indicates that the powertrain or transmission control module detected a high voltage condition on the transmission fluid temperature (TFT) sensor “A” circuit. This generic OBD2 problem applies to many vehicles equipped with electronically controlled automatic transmissions.
The TFT sensor is typically a thermistor whose resistance changes with fluid temperature. The module supplies a reference voltage and monitors the signal return to calculate the exact fluid temperature.
When the module detects voltage remaining high when it should be lower, or detects an open circuit, it stores this code. This is an electrical fault, not necessarily an actual physical overheating condition.
Common Causes of the P0713 Code
Damage to the wiring harness or corroded connectors at the transmission fluid temperature sensor can cause this code. An open circuit or a short to voltage in the signal wire will prevent the module from reading correctly.
An internally failed TFT sensor can create an open circuit condition, causing the control module to detect high voltage on the signal line.
In vehicles where the sensor is integrated into the transmission internal wiring harness or valve body, chafing or fluid contamination can damage the internal circuits.
Symptoms Associated With P0713
An illuminated Check Engine Light is expected once the monitor detects the circuit fault. MIL behavior varies by application, but the light commands when the electrical fault is verified.
You may experience harsh or erratic gear shifting. The control module uses fluid temperature data to adjust shift timing and line pressure; without accurate data, it defaults to a fail-safe shift strategy.
In some applications, the transmission may enter a limp mode or disable torque converter clutch lockup to protect the internal components from perceived overheating.
Diagnosing the P0713 Trouble Code
Diagnosis must begin by confirming the exact factory definition and checking for related transmission codes. Record freeze-frame data to see the conditions when the code set.
Perform a thorough visual inspection of the wiring harness and connectors at the transmission case and the control module. Look for chafed wires, broken insulation, corrosion, or loose pins.
Use a scan tool to view the live transmission fluid temperature data. Compare the reading to the ambient air temperature or engine coolant temperature on a cold engine to check for rationality.
Use a multimeter to test the signal circuit for continuity, shorts to voltage, and open circuits. Measure the internal resistance of the TFT sensor and compare it to the manufacturer specification.
Repairing the P0713 Issue
Repairs must follow confirmed diagnosis. If the wiring harness is found to be broken, shorted, or corroded, repair the circuit and secure the harness to prevent future damage.
If electrical testing confirms the transmission fluid temperature sensor is internally open or fails the manufacturer resistance test, replace the sensor using a component meeting the exact vehicle specification.
If the sensor is integrated into the transmission internal harness or valve body assembly, the transmission pan must be removed to access and replace the internal components.
Cost Considerations for P0713 Repairs
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Repairing damaged external wiring or replacing an externally mounted sensor involves moderate parts and labor expenses.
If the sensor is integrated into the internal transmission wiring harness or valve body, the transmission fluid must be drained and the pan removed, which increases labor hours and overall repair costs.
Prevention Strategies for Future Occurrences
Inspecting exposed transmission wiring harnesses and connectors during routine under-vehicle service can help identify developing insulation damage or moisture intrusion before it causes an open circuit.
Keeping connector seals intact and ensuring wiring is properly secured away from hot exhaust components or moving driveline parts may reduce the risk of circuit faults.
Some electrical failures occur due to normal component aging or internal transmission wear and cannot be reliably prevented through standard maintenance.
Troubleshooting Tips and Best Practices
Do not attempt to fix a P0713 code by simply changing the transmission fluid. This code specifically targets an electrical circuit fault, not the physical condition or level of the fluid.
Always verify the reference voltage and ground circuits at the sensor connector before condemning the sensor itself. A missing ground will mimic an open circuit or high voltage condition.
Check for technical service bulletins for your exact vehicle application, as some manufacturers release updated internal wiring harnesses or revised sensor designs to address chronic connector failures.
More OBD-II Codes
| P0703 | P0704 | P0705 | P0706 |
| P0707 | P0708 | P0714 | P0715 |
| P0716 | P0717 | P0720 | P0721 |
| P0711 | P0722 | P0723 | P0726 |
| P0727 | P0730 | P0731 | P0732 |
| P0733 | P0734 | P0735 | P0736 |
Frequently Asked Questions
Is the P0713 code generic or manufacturer-specific?
Yes, P0713 is a generic SAE OBD-II diagnostic trouble code. However, the exact transmission wiring architecture and diagnostic steps vary by manufacturer and vehicle application.
Will a P0713 code affect my transmission shifting?
Yes. The control module uses fluid temperature data to adjust shift timing and line pressure. Without accurate data, it may default to harsh shifts or a fail-safe strategy.
Does a P0713 code mean my transmission is overheating?
Not necessarily. This code indicates an electrical circuit fault, such as an open circuit or short to voltage. It does not automatically prove the physical fluid temperature is excessively high.
Does a P0713 code mean I need a new transmission?
No. While the sensor is often located inside the transmission pan, the code is frequently caused by damaged external wiring or corroded connectors. Proper electrical testing is required first.
Can I clear the P0713 code without fixing the problem?
Clearing the code only resets the warning light. If the underlying wiring fault or failed sensor remains, the monitor will detect the high voltage condition immediately and turn the light back on.
What Should You Do About the P0713 Code?
Confirm the exact factory definition and check for related transmission codes for your specific vehicle application. Follow the applicable manufacturer diagnostic procedure to verify whether the fault lies in the wiring, connectors, or the transmission fluid temperature sensor itself.
Once testing confirms the root cause, repair or replace the confirmed failed component in the relevant system, then retest the live data to ensure the temperature readings are accurate and rational.
