P079E - Transmission Fluid Temperature Sensor Range/Performance Problem Explained for Honda and Toyota Models

Quick Answer

P079E means: P079E indicates a problem with the transmission fluid temperature sensor's range or performance.

Fix: Check and replace faulty components Cost: $150 - $300 Time: 90-180 minutes

Can I drive with P079E? It is advised to diagnose and fix this issue promptly to avoid potential transmission damage.

Common Questions

What does P079E mean and how does it affect my car?

The P079E code indicates a problem with your vehicle's transmission fluid temperature sensor, which is crucial for optimal transmission performance. If this code triggers, it can lead to issues such as erratic shifting, decreased fuel efficiency, and potentially severe transmission damage if not addressed quickly.

What are the most common causes of P079E and how much does it cost to fix?

Common causes of P079E include a faulty transmission fluid temperature sensor, poor electrical connections, and low fluid levels. Repair costs can vary widely, ranging from $150 for a sensor replacement to $600 for ECM issues, depending on the specific problem.

Can I drive my car with P079E or should I stop immediately?

While it may be possible to drive with the P079E code, it is not advisable. Continuing to drive could exacerbate transmission issues, leading to more expensive repairs. It’s best to have the vehicle diagnosed and repaired as soon as possible.

How can I diagnose P079E myself using GeekOBD APP?

Using the GeekOBD APP, you can scan your vehicle for DTCs, analyze freeze frame data, and monitor live sensor readings. Check for voltage and resistance at the transmission fluid temperature sensor to assess its condition and identify any potential faults.

What vehicles are most commonly affected by P079E?

P079E is commonly found in vehicles like the 2015-2018 Honda Accord and the 2016-2019 Toyota Camry. It's advisable to check for any recalls or technical service bulletins (TSBs) related to the transmission system in these models.

How can I prevent P079E from happening again?

To prevent the P079E code from recurring, ensure regular transmission fluid changes, inspect wiring and connectors for damage, and keep an eye on fluid levels. Regular diagnostics using tools like the GeekOBD APP can also help catch issues before they escalate.

What is P079E?

The diagnostic trouble code (DTC) P079E indicates an issue with the transmission fluid temperature sensor range or performance. This code is primarily found in vehicles equipped with automatic transmissions, particularly common in models like the 2015-2018 Honda Accord and 2016-2019 Toyota Camry. The transmission fluid temperature sensor plays a crucial role in monitoring the temperature of the transmission fluid, helping the engine control module (ECM) adjust the transmission's performance. When the sensor detects a reading outside the expected range—either too high or too low—it triggers the P079E code. This issue can lead to various transmission-related problems, including erratic shifting, overheating, or reduced acceleration. If left unaddressed, it can cause severe transmission damage, leading to costly repairs. Car owners may notice symptoms like the check engine light illuminating, unusual shifting behavior, or a decrease in overall vehicle performance. Regular maintenance and timely diagnostics are essential to prevent this code from affecting your driving experience.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P079E is present:

  • Check engine light remains illuminated, indicating a fault in the transmission fluid temperature sensor.
  • The vehicle experiences erratic shifting patterns, such as harsh or delayed shifts during acceleration.
  • Drivers may notice a significant decrease in fuel economy, potentially by 10-15% due to improper transmission operation.
  • Transmission overheating may occur, leading to a burning smell or fluid leaks under the vehicle.
  • The vehicle may struggle to accelerate smoothly, causing hesitation or stalling.

Possible Causes

Most common causes of P079E (ordered by frequency):

  1. The most common cause is a faulty transmission fluid temperature sensor, occurring in approximately 60% of cases. This can be due to wear and tear or electrical issues.
  2. A second frequent cause involves poor electrical connections, including corroded connectors or damaged wiring, which can lead to intermittent readings.
  3. The third potential cause is low transmission fluid levels, which can result from leaks; ensuring regular fluid checks can help prevent this.
  4. Less commonly, a malfunctioning ECM can cause misinterpretation of sensor data, potentially leading to erroneous code triggering.
  5. In rare cases, internal transmission damage due to overheating or contamination can also trigger the P079E code.

P079E Repair Costs

Cost Breakdown by Repair Type

Transmission Fluid Temperature Sensor Replacement

Replacing the faulty sensor with a new one to restore proper functionality.

  • Total: $150 - $300
  • Success rate: 85%
Wiring Harness Repair

Repairing or replacing damaged wiring or connectors.

  • Total: $100 - $200
  • Success rate: 75%
ECM Reprogramming

Reprogramming or replacing the ECM if it is found to be faulty.

  • Total: $200 - $600
  • Success rate: 90%
Money-Saving Tips for P079E
  • Start with the most common and least expensive repairs first
  • Use GeekOBD APP to confirm diagnosis before replacing expensive parts
  • Consider preventive maintenance to avoid future occurrences
  • Compare prices for OEM vs aftermarket parts based on your needs
  • Address the issue promptly to prevent more expensive secondary damage

Diagnostic Steps

Professional P079E Diagnosis Process

Follow these systematic steps to accurately diagnose P079E. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Perform an initial visual inspection of the transmission wiring harness and connectors for damage or corrosion (5-10 minutes)

Step 1: Perform an initial visual inspection of the transmission wiring harness and connectors for damage or corrosion (5-10 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 2: Step 2: Use a diagnostic tool, such as the GeekOBD APP, to scan for all DTCs and review freeze frame data for context (10-15 minutes)

Step 2: Use a diagnostic tool, such as the GeekOBD APP, to scan for all DTCs and review freeze frame data for context (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Test the transmission fluid temperature sensor using a multimeter to check for proper voltage and resistance readings (20-30 minutes)

Step 3: Test the transmission fluid temperature sensor using a multimeter to check for proper voltage and resistance readings (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: Conduct a system function test after repairs, ensuring that the transmission operates smoothly and that codes are cleared (10-15 minutes)

Step 4: Conduct a system function test after repairs, ensuring that the transmission operates smoothly and that codes are cleared (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Take the vehicle for a road test to verify that all symptoms are resolved and the transmission operates as expected (15-20 minutes)

Step 5: Take the vehicle for a road test to verify that all symptoms are resolved and the transmission operates as expected (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

Important Notes

  • Always verify the repair with GeekOBD APP after completing diagnostic steps
  • Clear codes and test drive to ensure the problem is resolved
  • Address underlying causes to prevent code recurrence

Real Repair Case Studies

Case Study 1: Transmission Fluid Temperature Sensor Replacement on 2017 Honda Accord

Vehicle: 2017 Honda Accord, 45,000 miles

Problem: Customer reported check engine light and erratic shifting.

Diagnosis: Performed a diagnostic scan which revealed P079E. Inspected the sensor and found it was faulty.

Solution: Replaced the transmission fluid temperature sensor and changed the transmission fluid.

Cost: $280 (sensor: $150, fluid: $130)

Result: Check engine light turned off, and shifting returned to normal.

Case Study 2: Wiring Harness Repair for 2016 Toyota Camry

Vehicle: 2016 Toyota Camry, 60,000 miles

Problem: Customer complained of poor acceleration and a check engine light.

Diagnosis: Diagnosis revealed P079E; inspection showed corroded wiring in the harness.

Solution: Repaired the wiring harness and reconnected the sensor.

Cost: $180 (parts and labor included)

Result: Vehicle performance improved, and no further issues were noted.

Diagnose P079E

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P079E
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes