Quick Answer
P0979 means: P0979 indicates a malfunction with the transmission fluid pressure sensor, affecting transmission performance.
Can I drive with P0979? Immediate attention is required to prevent potential transmission damage.
Common Questions
What does P0979 mean and how does it affect my car?
The P0979 code indicates a problem with the transmission fluid pressure sensor, which can lead to rough shifting and reduced performance. If ignored, it may result in severe transmission damage and costly repairs.
What are the most common causes of P0979 and how much does it cost to fix?
Common causes include a faulty sensor and wiring issues. Repair costs typically range from $150 to $300 for sensor replacement, depending on labor rates and parts.
Can I drive my car with P0979 or should I stop immediately?
It is advisable to stop driving and address the issue promptly. Continuing to drive can lead to further transmission damage and increased repair costs.
How can I diagnose P0979 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for codes, view live data, and check the performance of the transmission fluid pressure sensor to help identify the problem.
What vehicles are most commonly affected by P0979?
Vehicles like the 2012-2018 Chevrolet Silverado, 2014-2018 GMC Sierra, and 2015-2018 Ford F-150 are frequently affected by this code.
How can I prevent P0979 from happening again?
Regular maintenance, including checking transmission fluid levels and replacing the fluid at recommended intervals, can help prevent P0979 from recurring.
What is P0979?
The P0979 Diagnostic Trouble Code (DTC) indicates a problem with the transmission fluid pressure sensor range or its performance. This sensor plays a crucial role in monitoring the hydraulic pressure within the transmission system. When the engine control module (ECM) detects that the pressure readings from the sensor are outside the expected range, it triggers the P0979 code. Commonly found in vehicles like the 2012-2018 Chevrolet Silverado, 2014-2018 GMC Sierra, and 2015-2018 Ford F-150, this issue can lead to various transmission problems, including rough shifting, slipping gears, and even complete transmission failure if left unaddressed. Drivers may notice symptoms like the check engine light illuminating, erratic gear changes, or decreased fuel efficiency. Ignoring this code can lead to more severe damage and costly repairs, as the transmission is a complex system that heavily relies on accurate pressure readings to function efficiently.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P0979 is present:
- The check engine light stays on constantly, indicating an issue with the transmission fluid pressure sensor.
- Drivers may experience engine hesitations during acceleration, making the vehicle feel sluggish or unresponsive.
- Fuel economy could decrease by 10-15%, leading to increased operational costs as the vehicle struggles to maintain efficiency.
- Erratic shifting, where the transmission shifts unexpectedly or harshly, may occur, causing discomfort during driving.
- In severe cases, the vehicle may go into limp mode, limiting speed and acceleration to protect the transmission from further damage.
Possible Causes
Most common causes of P0979 (ordered by frequency):
- The most common cause is a faulty transmission fluid pressure sensor, accounting for about 60% of cases. This can happen due to wear and tear or exposure to extreme temperatures.
- A second common cause is wiring issues, such as damaged or corroded connectors. These can disrupt the signal transmission between the sensor and the ECM.
- Another potential cause is low transmission fluid levels, which can lead to inaccurate pressure readings. Regular fluid checks can help prevent this.
- Less common but serious causes include internal transmission damage, which might require extensive repairs or a complete rebuild.
- A rare cause could be a malfunctioning ECM, which may misinterpret sensor data due to software issues or hardware failure.
P0979 Repair Costs
Cost Breakdown by Repair Type
Transmission Fluid Pressure Sensor Replacement
Replacing the faulty transmission fluid pressure sensor with a new OEM or aftermarket part.
- Total: $150 - $300
- Success rate: 90%
Money-Saving Tips for P0979
- 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 P0979 Diagnosis Process
Follow these systematic steps to accurately diagnose P0979. 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 pressure sensor and associated wiring (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid pressure sensor and associated wiring (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the issue is resolved (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the issue is resolved (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 Sensor Replacement on 2015 Ford F-150
Vehicle: 2015 Ford F-150, 85,000 miles
Problem: Customer reported check engine light on and rough shifting.
Diagnosis: Diagnostic scan revealed P0979 with symptoms of erratic gear changes.
Solution: Replaced the transmission fluid pressure sensor and topped off the transmission fluid.
Cost: $220 (sensor: $120, labor: $100)
Result: Post-repair, the check engine light was cleared, and the vehicle shifted smoothly.
Case Study 2: Wiring Repair on 2014 Chevrolet Silverado
Vehicle: 2014 Chevrolet Silverado, 90,000 miles
Problem: Check engine light on and poor acceleration.
Diagnosis: Found damaged wiring harness connected to the transmission fluid pressure sensor.
Solution: Repaired the wiring harness and replaced the sensor.
Cost: $270 (sensor: $150, labor: $120)
Result: After repairs, the vehicle performed well, and no further codes appeared.