P0714 - Transmission Fluid Temperature Sensor Circuit Intermittent

Introduction:

The P0714 diagnostic trouble code (DTC) indicates an intermittent problem with the Transmission Fluid Temperature (TFT) sensor circuit in your vehicle's automatic transmission. This sensor is crucial for monitoring the temperature of the transmission fluid, which is vital for the transmission's overall health and performance. When the Powertrain Control Module (PCM) detects an irregular or unstable signal from the TFT sensor, it triggers the P0714 code. Addressing this issue promptly is important to prevent potential transmission damage and ensure proper vehicle operation.

P0714 Code: A Comprehensive Overview

Here's a detailed table summarizing key aspects of the P0714 code:

Aspect	Description	Potential Symptoms
Definition	Transmission Fluid Temperature Sensor Circuit Intermittent. Indicates the PCM is receiving an erratic or unstable signal from the TFT sensor. The signal fluctuates beyond acceptable parameters, causing the PCM to register an intermittent fault rather than a constant high or low reading.	Check Engine Light (CEL) illumination. Erratic shifting behavior. Delayed engagement of gears. Transmission slippage. Reduced fuel economy. Potential transmission overheating. * Transmission entering "limp mode".
Possible Causes	Faulty Transmission Fluid Temperature (TFT) sensor. Damaged or corroded wiring and connectors in the TFT sensor circuit. Open or short circuit in the TFT sensor wiring. Poor electrical connection at the PCM or transmission connector. Low transmission fluid level. Contaminated or degraded transmission fluid. * Failing PCM (rare).	N/A
Diagnostic & Repair Steps	1. Verify the code: Use a scan tool to confirm the P0714 code is present. 2. Check transmission fluid level and condition: Ensure the fluid is at the proper level and free from contaminants. Change if necessary. 3. Inspect wiring and connectors: Visually inspect the wiring harness and connectors associated with the TFT sensor for damage, corrosion, or loose connections. Repair or replace as needed. 4. Test the TFT sensor: Use a multimeter to check the sensor's resistance at various temperatures. Compare readings to the manufacturer's specifications. Replace if faulty. 5. Check the TFT sensor circuit: Use a multimeter to check for continuity and voltage in the TFT sensor circuit. Identify and repair any open circuits, short circuits, or high resistance. 6. Inspect the PCM: Examine the PCM and transmission connectors for corrosion or damage. 7. Clear the code and retest: After completing repairs, clear the P0714 code and test drive the vehicle to see if the code returns. 8. Consult a professional: If you are unable to diagnose or repair the problem yourself, consult a qualified mechanic.	N/A

Detailed Explanations

1. Definition: Transmission Fluid Temperature Sensor Circuit Intermittent

The P0714 code signals that the PCM is experiencing an inconsistent or unstable signal from the TFT sensor. The "intermittent" nature of the fault means the problem doesn't exist constantly, making diagnosis potentially more challenging. This fluctuation outside of acceptable parameters triggers the code and alerts the driver to a potential issue.

2. Possible Causes: Faulty Transmission Fluid Temperature (TFT) sensor

The TFT sensor itself could be failing, providing inaccurate readings to the PCM. Internal damage or degradation of the sensor components can lead to erratic signals. This is often the primary suspect, especially if the sensor is old or has been exposed to harsh conditions.

3. Possible Causes: Damaged or corroded wiring and connectors in the TFT sensor circuit

The wiring and connectors connecting the TFT sensor to the PCM are susceptible to damage from heat, vibration, and environmental factors. Corrosion can build up on the connectors, creating resistance and disrupting the signal. Damaged wires, such as those that are frayed or broken, can also cause intermittent connections.

4. Possible Causes: Open or short circuit in the TFT sensor wiring

An open circuit means the electrical path is broken, preventing the signal from reaching the PCM. A short circuit occurs when the wiring comes into contact with ground or another wire, diverting the signal. Both of these conditions can lead to inaccurate temperature readings and trigger the P0714 code.

5. Possible Causes: Poor electrical connection at the PCM or transmission connector

Loose or corroded connections at the PCM or transmission connector can disrupt the signal flow. These connections are often exposed to the elements and can degrade over time. Ensuring these connections are clean and secure is crucial for proper sensor operation.

6. Possible Causes: Low transmission fluid level

While less direct, a low transmission fluid level can contribute to the P0714 code. Insufficient fluid can lead to overheating, which the TFT sensor will detect. Although the code specifically points to the sensor circuit, low fluid can exacerbate any existing sensor issues or create conditions that trigger the code.

7. Possible Causes: Contaminated or degraded transmission fluid

Dirty or degraded transmission fluid can affect the sensor's ability to accurately measure temperature. Contaminants can insulate the sensor, while degraded fluid may not transfer heat efficiently. This can lead to inaccurate readings and trigger the P0714 code.

8. Possible Causes: Failing PCM (rare)

Although less common, a faulty PCM can also be the cause of the P0714 code. The PCM is responsible for interpreting the signal from the TFT sensor, and if it is malfunctioning, it may misinterpret the signal and trigger the code. This is usually considered a last resort diagnosis after ruling out other potential causes.

9. Potential Symptoms: Check Engine Light (CEL) illumination

The most immediate symptom is the illumination of the Check Engine Light (CEL) on the dashboard. This light indicates that the PCM has detected a fault in the vehicle's system. A scan tool is needed to confirm that the P0714 code is present.

10. Potential Symptoms: Erratic shifting behavior

The PCM uses the TFT sensor data to optimize shifting strategies. When the sensor signal is intermittent, the PCM may struggle to determine the optimal shift points, leading to erratic or unpredictable shifting behavior. This can include harsh shifts, delayed shifts, or failure to shift at all.

11. Potential Symptoms: Delayed engagement of gears

The PCM relies on TFT sensor data to properly engage gears. An inaccurate signal can cause delays in gear engagement, especially when shifting from park to drive or reverse. This delay can be noticeable and potentially concerning to the driver.

12. Potential Symptoms: Transmission slippage

Transmission slippage occurs when the transmission fails to properly transfer power from the engine to the wheels. This can be caused by a variety of factors, including low transmission fluid, worn clutches, or a faulty TFT sensor. The intermittent signal from a faulty sensor can cause the PCM to make incorrect adjustments, leading to slippage.

13. Potential Symptoms: Reduced fuel economy

Inefficient shifting caused by the P0714 code can lead to reduced fuel economy. The transmission may be operating outside of its optimal range, causing the engine to work harder and consume more fuel.

14. Potential Symptoms: Potential transmission overheating

While the TFT sensor's primary function is to monitor temperature, a faulty sensor can indirectly contribute to overheating. If the PCM is receiving inaccurate temperature data, it may not take appropriate measures to prevent overheating, potentially leading to damage.

15. Potential Symptoms: Transmission entering "limp mode"

In some cases, the PCM may put the transmission into "limp mode" to protect it from further damage. Limp mode typically limits the transmission to a single gear, reducing the vehicle's speed and power. This is a safety measure designed to prevent catastrophic failure.

16. Diagnostic & Repair Steps: Verify the code

Using an OBD-II scanner is the first step to confirm the presence of the P0714 code. This eliminates guesswork and ensures that the repair efforts are focused on the correct problem.

17. Diagnostic & Repair Steps: Check transmission fluid level and condition

Ensure the transmission fluid is at the correct level and is clean. Low or contaminated fluid can contribute to transmission problems. Checking the fluid level is typically done using a dipstick, while the condition can be assessed by examining the fluid's color and smell. Dark, burnt-smelling fluid indicates a problem.

18. Diagnostic & Repair Steps: Inspect wiring and connectors

Visually inspect the wiring and connectors associated with the TFT sensor for any signs of damage, corrosion, or loose connections. Pay close attention to areas where the wiring may be exposed to heat or vibration. Repair or replace any damaged components. Use dielectric grease on connectors to prevent future corrosion.

19. Diagnostic & Repair Steps: Test the TFT sensor

Use a multimeter to measure the resistance of the TFT sensor at different temperatures. Compare these readings to the manufacturer's specifications. A faulty sensor will typically have resistance values that are outside of the specified range.

20. Diagnostic & Repair Steps: Check the TFT sensor circuit

Use a multimeter to check for continuity and voltage in the TFT sensor circuit. This will help identify any open circuits, short circuits, or high resistance. Refer to the vehicle's wiring diagram for specific test points and voltage values.

21. Diagnostic & Repair Steps: Inspect the PCM

Examine the PCM and transmission connectors for corrosion or damage. Clean any corroded terminals and ensure that the connectors are securely attached.

22. Diagnostic & Repair Steps: Clear the code and retest

After completing any repairs, clear the P0714 code using a scan tool and test drive the vehicle to see if the code returns. This will help verify that the repair was successful. Monitor the transmission temperature during the test drive to ensure it is within the normal operating range.

23. Diagnostic & Repair Steps: Consult a professional

If you are unable to diagnose or repair the problem yourself, consult a qualified mechanic. A professional mechanic has the expertise and tools necessary to diagnose and repair complex transmission problems.

Frequently Asked Questions

What does the P0714 code mean? It means the PCM detects an intermittent signal from the transmission fluid temperature sensor circuit.
Can I drive with a P0714 code? While you can drive, it's not recommended. The transmission may be operating inefficiently, and continued driving could lead to further damage.
How do I fix the P0714 code? Start by checking the transmission fluid level and condition, then inspect the wiring and connectors for damage. You may need to replace the TFT sensor or repair wiring issues.
How much does it cost to fix a P0714 code? The cost can vary widely depending on the cause. Replacing the sensor is relatively inexpensive, while more complex wiring repairs or PCM replacement can be significantly more costly. Expect to pay anywhere from $100 to $500 or more.
Is the P0714 code serious? Yes, it can be serious if left unaddressed. It can lead to transmission damage and costly repairs.

Conclusion

The P0714 code indicates an intermittent fault in the transmission fluid temperature sensor circuit. Prompt diagnosis and repair are essential to prevent potential transmission damage and ensure smooth vehicle operation, it is recommended to start with the easiest and cheapest solution, which is to check the transmission fluid level and condition.