Quick Answer
P079F means: P079F indicates a problem with the transmission fluid temperature sensor's performance.
Can I drive with P079F? It is advisable to address this code immediately to avoid potential transmission damage.
Common Questions
What does P079F mean and how does it affect my car?
The P079F code signifies a problem with the transmission fluid temperature sensor. If this sensor malfunctions, it can lead to poor transmission performance, erratic shifting, and increased wear on the transmission components. Over time, neglecting this issue can result in more severe transmission problems, leading to costly repairs and potential vehicle breakdowns.
What are the most common causes of P079F and how much does it cost to fix?
The leading cause of the P079F code is a faulty transmission fluid temperature sensor, which can cost between $150 and $300 to replace. Additionally, wiring issues can also trigger this code, with repair costs ranging from $100 to $200. Keeping your transmission fluid clean and at the proper level can help prevent these issues.
Can I drive my car with P079F or should I stop immediately?
Driving with the P079F code is not recommended, as it can lead to transmission overheating and potential failure. If you notice symptoms like erratic shifting or slipping, it's best to have your vehicle checked immediately to avoid further damage.
How can I diagnose P079F myself using GeekOBD APP?
To diagnose the P079F code using the GeekOBD APP, start by connecting the app to your vehicle’s OBD2 port. Use the app to retrieve the trouble codes and check for any freeze frame data that indicates the conditions under which the code was triggered. You can also monitor live data, focusing on the transmission fluid temperature readings to identify inconsistencies.
What vehicles are most commonly affected by P079F?
The P079F code is commonly found in vehicles such as the 2015-2019 Ford Focus and 2017-2019 Chevrolet Malibu. Other makes and models equipped with automatic transmissions may also experience this issue, especially those that have been on the road for several years without regular maintenance.
How can I prevent P079F from happening again?
To prevent the P079F code from recurring, regularly check and change your transmission fluid according to the manufacturer's maintenance schedule. Additionally, inspect the wiring and connectors associated with the transmission fluid temperature sensor during routine vehicle checks to ensure they are in good condition.
What is P079F?
The P079F diagnostic trouble code indicates a problem with the transmission fluid temperature sensor circuit, commonly found in vehicles like the 2015-2019 Ford Focus, 2017-2019 Chevrolet Malibu, and various other vehicles equipped with automatic transmissions. This code is triggered when the Engine Control Module (ECM) detects that the temperature readings from the sensor are out of the expected range. The transmission fluid temperature sensor plays a crucial role in monitoring the fluid's temperature to ensure optimal transmission performance. Elevated temperatures can lead to premature wear, reduced efficiency, and ultimately, transmission failure. When this code is present, it typically indicates that the sensor may be malfunctioning, or there could be an issue with the wiring or connectors. Ignoring this trouble code can lead to more severe transmission problems, causing significant repair costs and possibly leaving you stranded. In many cases, you may notice symptoms such as erratic shifting, slipping, or even overheating of the transmission fluid, all of which can affect your vehicle's drivability. Addressing this code promptly by diagnosing the root cause can save you from costly repairs down the line.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P079F is present:
- Check engine light illuminates and stays on, indicating a fault in the transmission system.
- Transmission may hesitate or jerk during gear shifts, leading to a rough driving experience.
- Fuel economy may decrease significantly, possibly by 10-15%, due to inefficient transmission operation.
- Unusual transmission fluid smells or signs of overheating may be noticed, such as burnt fluid.
- In extreme cases, the vehicle may enter 'limp mode,' significantly restricting performance and speed.
Possible Causes
Most common causes of P079F (ordered by frequency):
- The most common cause is a faulty transmission fluid temperature sensor, which accounts for about 60% of cases. This sensor may fail due to wear and tear or exposure to extreme temperatures.
- A second cause could be wiring issues, such as damaged or corroded wires connected to the sensor. This can lead to intermittent signals that confuse the ECM.
- Another cause may be low or contaminated transmission fluid, which can affect sensor readings. Regular monitoring of fluid levels and quality can help prevent this issue.
- Less commonly, a malfunctioning ECM could falsely trigger the P079F code. In this case, professional diagnosis will be necessary.
- A rare but possible cause is a complete transmission failure, which could manifest as other symptoms before triggering the P079F code.
P079F Repair Costs
Cost Breakdown by Repair Type
Transmission Fluid Temperature Sensor Replacement
Replacing the faulty sensor with a new OEM or aftermarket part.
- Total: $150 - $300
- Success rate: 85%
Wiring Repair
Repairing or replacing damaged wiring or connectors associated with the sensor.
- Total: $100 - $200
- Success rate: 75%
Money-Saving Tips for P079F
- 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 P079F Diagnosis Process
Follow these systematic steps to accurately diagnose P079F. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid temperature sensor's output (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid temperature sensor's output (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation of the transmission after repairs and clear the codes (10-15 minutes)
Step 4: System function test - Verify proper operation of the transmission after repairs and clear the codes (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success, checking for any return of the code (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success, checking for any return of the code (15-20 minutes).
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 Ford Focus
Vehicle: 2016 Ford Focus, 45,000 miles
Problem: The customer reported a persistent check engine light and erratic shifting.
Diagnosis: After scanning with the GeekOBD APP, the P079F code was retrieved. A visual inspection revealed a faulty transmission fluid temperature sensor.
Solution: The technician replaced the sensor and performed a fluid change to ensure optimal performance.
Cost: $250 (sensor: $150, labor: $100)
Result: The check engine light was cleared, and the customer reported smooth shifting and improved drivability.
Case Study 2: Wiring Repair in a 2018 Chevrolet Malibu
Vehicle: 2018 Chevrolet Malibu, 30,000 miles
Problem: The vehicle displayed a check engine light and poor transmission performance.
Diagnosis: The OBD2 scan revealed the P079F code, and further inspection showed damaged wiring to the temperature sensor.
Solution: The technician repaired the wiring harness and ensured all connections were secure.
Cost: $150 (labor and materials)
Result: Post-repair, the vehicle functioned normally with no recurrence of the P079F code.