P0079 Trouble Code: Meaning, Symptoms, Causes & Fixes

If you’re noticing the P0079 trouble code flashing on your car’s dashboard, you’re likely seeking clarity on what it means and how to address it.

This guide promises a comprehensive breakdown of the P0079 code, detailing its meaning, symptoms, causes, and reliable fixes. Whether you’re a DIY enthusiast or just trying to understand your vehicle better, this article has got you covered.

Having fixed numerous vehicles with the P0079 error, I can confidently guide you through resolving it efficiently.

In this article, I’ll delve into common symptoms that accompany the P0079 code and explore the most effective troubleshooting steps. You’ll learn not just to diagnose but also to remedy this issue at home.

Ready to get to the bottom of it? Let’s roll up our sleeves and get started.

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What Does P0079 Trouble Code Mean?

When your car’s system spits out a P0079 trouble code, it’s pinpointing a specific issue in the exhaust valve control circuit in Bank 1 of your engine.

This part of your car is crucial for controlling the flow of exhaust gases out of the engine cylinders, and it operates under the command of the Engine Control Module (ECM).

Essentially, the “low” part of the code indicates that the ECM has detected a lower than expected voltage from the exhaust valve control solenoid.

This solenoid is an electromechanical device that regulates the opening and closing of the exhaust valves.

It uses voltage to manage the timing and amount of exhaust released, which helps optimize engine performance and efficiency.

In simpler terms, think of it as a traffic cop that directs the flow of exhaust gases. If the signal it sends is too weak (low voltage), the valves may not operate correctly, leading to less than optimal engine performance.

This can manifest in a variety of engine issues, from reduced fuel efficiency to increased emissions, which might cause your vehicle to fail emissions testing.

Understanding that a P0079 is an electrical issue helps focus the troubleshooting process. It’s not about mechanical valve failure, but about the electrical signal that controls these mechanical components.

For the everyday driver, this means the problem might involve a faulty solenoid, bad wiring, or issues with the ECM itself rather than the more complex internal engine repairs.

By identifying this trouble code early, you can address the issue before it leads to more significant engine performance problems.

Remember, timely maintenance and repairs not only save you from bigger repair bills down the road but also keep your ride smooth and efficient.

P0079 Trouble Code Symptoms

When the P0079 trouble code is active, your vehicle may exhibit several noticeable symptoms. Here’s a rundown of what to keep an eye out for:

• Reduced Engine Performance: The engine might not feel as responsive, particularly during acceleration.
• Rough Idling: You may notice that the engine shakes more than usual when the car is idling.
• Increased Fuel Consumption: The engine’s inefficiency may lead to using more fuel than normal.
• Failed Emissions Test: Due to improper exhaust valve operation, the vehicle might emit higher levels of pollutants, failing emissions standards.
• Check Engine Light: This light will likely illuminate on your dashboard as a direct indicator of the problem.

P0079 Trouble Code Causes

Several factors can trigger the P0079 trouble code in your vehicle. Here are the most common causes to consider:

• Faulty Exhaust Valve Control Solenoid: If this solenoid fails, it can’t properly manage the exhaust valves’ operations.
• Poor Electrical Connection: Issues such as loose or corroded connections in the solenoid circuit can lead to this error.
• Wiring Issues: Damaged or frayed wires leading to the solenoid can interrupt the circuit’s integrity.
• ECM Problems: Occasionally, a malfunctioning Engine Control Module could incorrectly interpret solenoid operation as faulty.
• Shorted or Open Solenoid Circuit: This could be due to wiring problems or failures within the solenoid itself.

How To Fix A P0079 Trouble Code

Fixing a P0079 trouble code involves diagnosing the issue accurately and then addressing the root cause to restore proper function to your vehicle’s exhaust valve control system. Here’s a step-by-step guide on how to tackle this repair:

1. Visual Inspection

Start by checking the exhaust valve control solenoid and its connections for any obvious signs of damage such as corrosion, wear, or loose connections. Ensure that the wiring and connectors are secure and in good condition.

2. Check the Solenoid

Using a multimeter, test the exhaust valve control solenoid to confirm it is receiving the correct voltage. Compare your readings with the specifications in your vehicle’s service manual. A solenoid not receiving enough voltage or showing resistance outside the specifications may need replacement.

3. Solenoid Replacement

If the solenoid is defective, replace it. This typically involves disconnecting the electrical connector, removing the solenoid from the valve assembly, and installing a new solenoid. Reconnect the wiring and ensure it’s secured properly.

4. Inspect the Wiring

If the solenoid appears functional, trace the wiring from the ECM to the solenoid. Look for any signs of damage, such as cuts, burns, or pinches. Repair any damaged wiring or replace sections if necessary.

5. Check the ECM

If all other components test fine, consider that the ECM itself may be the issue. However, diagnosing and replacing the ECM should generally be handled by professionals, as it requires specific tools and expertise.

6. Clear the Code

Once repairs are made, use an OBD-II scanner to clear the P0079 code. Drive the vehicle and monitor to see if the code returns.

7. Follow-up Testing

If the code does not return and the vehicle is performing well, you likely have resolved the issue. If symptoms persist or the code reappears, further diagnosis might be needed to check for less common underlying problems.

By methodically working through these steps, you can effectively resolve a P0079 trouble code, ensuring your engine operates efficiently and your vehicle remains reliable.

Conclusion

Now that we’ve covered what the P0079 trouble code means and how you can tackle it, you’re equipped to handle this issue more confidently.

Have you encountered this error before in your vehicle?

Feel free to share your experience or tips in the comments below. How did you resolve it?