P079C - Transmission Fluid Temperature Sensor Range/Performance Problem in Honda and Toyota Models

Quick Answer

P079C means: P079C indicates a problem with the Transmission Fluid Temperature Sensor, affecting transmission performance.

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

Can I drive with P079C? Immediate attention is recommended to prevent transmission damage.

Common Questions

What does P079C mean and how does it affect my car?

The P079C code indicates a malfunction in the Transmission Fluid Temperature Sensor, which can lead to harsh shifting and decreased fuel efficiency. Ignoring this code may result in serious transmission damage.

What are the most common causes of P079C and how much does it cost to fix?

Common causes include a faulty sensor (60% chance), damaged wiring, low fluid levels, or a failing control module. Repair costs can range from $80 to $300 depending on the issue.

Can I drive my car with P079C or should I stop immediately?

Driving with a P079C code is not advisable as it can lead to further transmission damage. It's best to address this issue as soon as possible.

How can I diagnose P079C myself using GeekOBD APP?

Using the GeekOBD APP, you can scan for DTCs, view freeze frame data, and monitor sensor readings to help isolate the problem.

What vehicles are most commonly affected by P079C?

Commonly affected vehicles include the 2014-2017 Honda Accord and 2015-2018 Toyota Camry, among others. Check for any recalls or technical service bulletins related to this issue.

How can I prevent P079C from happening again?

Regular maintenance, including fluid changes and visual inspections of the wiring, can help prevent the occurrence of P079C. Keeping an eye on any transmission performance issues is also crucial.

What is P079C?

The P079C diagnostic trouble code (DTC) indicates a performance issue with the Transmission Fluid Temperature Sensor Circuit in vehicles such as the Honda Accord (2014-2017) and Toyota Camry (2015-2018). This sensor plays a crucial role in monitoring the temperature of the transmission fluid, which is essential for proper transmission operation. When the temperature deviates from the expected range, it can lead to adverse effects on the vehicle's shifting performance, fuel efficiency, and overall drivability. Drivers may notice symptoms like harsh shifting, slipping, or a decrease in power during acceleration. If left unaddressed, this issue can cause severe damage to the transmission system, leading to costly repairs. Understanding this code is vital for proactive maintenance and ensuring the longevity of your vehicle's performance.

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

Symptoms

Common symptoms when P079C is present:

  • The check engine light illuminates consistently, signaling a need for diagnostic attention.
  • Drivers may experience harsh or delayed shifting, particularly during acceleration or deceleration.
  • Fuel economy can decrease significantly, often by 10-15%, as the transmission struggles to operate efficiently.
  • Unusual transmission noises, such as grinding or whining, may be present during gear changes.
  • The vehicle may enter limp mode, limiting engine power to prevent further damage.

Possible Causes

Most common causes of P079C (ordered by frequency):

  1. The most common cause is a faulty Transmission Fluid Temperature Sensor, with a likelihood of around 60%. This can happen due to wear and tear or electrical issues.
  2. A second possibility is damaged wiring or connectors in the sensor circuit, leading to incorrect readings. This typically occurs due to corrosion or physical damage.
  3. A third cause could be low transmission fluid levels or fluid contamination, which can be prevented by regular maintenance checks and fluid changes.
  4. Less common but serious is a failing transmission control module (TCM), which can dramatically affect shifting and overall transmission performance.
  5. A rare cause could be software issues within the vehicle's engine control unit (ECU), which may require a software update.

P079C Repair Costs

Cost Breakdown by Repair Type

Sensor Replacement

Replaces the faulty Transmission Fluid Temperature Sensor to restore proper function.

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

Repairs or replaces damaged wiring and connectors in the sensor circuit.

  • Total: $100 - $250
  • Success rate: 75%
Transmission Fluid Change

Flushes and replaces old transmission fluid to ensure optimal transmission performance.

  • Total: $80 - $180
  • Success rate: 90%
Money-Saving Tips for P079C
  • 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 P079C Diagnosis Process

Follow these systematic steps to accurately diagnose P079C. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Initial visual inspection - Check for damaged wiring or loose connections related to the Transmission Fluid Temperature Sensor (5-10 minutes)

Step 1: Initial visual inspection - Check for damaged wiring or loose connections related to the Transmission Fluid Temperature Sensor (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: OBD2 scan with GeekOBD APP - Retrieve all DTCs and freeze frame data to understand the fault context better (10-15 minutes)

Step 2: OBD2 scan with GeekOBD APP - Retrieve all DTCs and freeze frame data to understand the fault context better (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: Component testing - Use a multimeter to test the Transmission Fluid Temperature Sensor and its circuit for proper voltage and resistance (20-30 minutes)

Step 3: Component testing - Use a multimeter to test the Transmission Fluid Temperature Sensor and its circuit for proper voltage and resistance (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: System function test - After making repairs, verify the proper operation of the sensor and clear any codes (10-15 minutes)

Step 4: System function test - After making repairs, verify the proper operation of the sensor and clear any codes (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: Road test verification - Drive the vehicle under various conditions to confirm the repair's success and monitor for any recurring issues (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm the repair's success and monitor for any recurring issues (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 in a 2016 Honda Accord

Vehicle: 2016 Honda Accord, 75,000 miles

Problem: Customer reported harsh shifting and check engine light illumination.

Diagnosis: Diagnostic scan revealed P079C. Sensor testing confirmed it was faulty.

Solution: Replaced the Transmission Fluid Temperature Sensor and cleared the codes.

Cost: $250 (sensor $150, labor $100)

Result: Customer reported smooth shifting and improved performance after the repair.

Case Study 2: Wiring Repair on a 2017 Toyota Camry

Vehicle: 2017 Toyota Camry, 60,000 miles

Problem: Check engine light on and slipping during gear changes.

Diagnosis: P079C was stored; visual inspection showed corrosion at the connector.

Solution: Repaired the wiring and connections, ensuring proper contact.

Cost: $150 (labor $100, wiring parts $50)

Result: Vehicle performance returned to normal, with no further issues reported.

Diagnose P079C

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: P079C
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes