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P0479 Mercedes-Benz Code - Exhaust Pressure Control Valve Intermittent

Quick Answer

The P0479 code for Mercedes-Benz vehicles indicates an issue with the exhaust pressure control valve being intermittent. Common causes include Faulty exhaust pressure control valve, Wiring or connector issues, ECM malfunction. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means
P0479 Mercedes-Benz indicates Exhaust Pressure Control Valve Intermittent.
Common causes
Common causes include Faulty exhaust pressure control valve, Wiring or connector issues, ECM malfunction.
Severity
Moderate - service should be scheduled soon.
Can I drive?
The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
What is this?
Table of contents Created and updated by William Orellana on Sep 12, 2024
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Code P0479 Mercedes-Benz Description

The P0479 code for Mercedes-Benz vehicles indicates an issue with the exhaust pressure control valve being intermittent. This valve is a crucial component of the vehicle's exhaust system, responsible for controlling the pressure within the exhaust system to optimize engine performance and emissions. When this valve malfunctions or operates intermittently, it can lead to a variety of issues that can impact the vehicle's performance, fuel efficiency, and emissions levels.

OBDII Code P0479 Mercedes-Benz - Exhaust Pressure Control Valve Intermittent
P0479 Mercedes-Benz Code - Exhaust Pressure Control Valve Intermittent

Common Causes of P0479 Mercedes-Benz

  1. Faulty exhaust pressure control valve
  2. Wiring or connector issues
  3. ECM malfunction
  4. Exhaust system leaks
  5. Carbon buildup in the exhaust pressure control valve

Symptoms of P0479 Mercedes-Benz

  1. Reduced engine performance or power
  2. Decreased fuel efficiency
  3. Illuminated check engine light
  4. Rough idling or stalling
  5. Increased emissions levels

How to Fix P0479 Mercedes-Benz

  1. Diagnose the issue by using a scan tool to retrieve the DTC and perform a visual inspection of the exhaust pressure control valve and related components.
  2. Test the exhaust pressure control valve and associated wiring for continuity and proper operation.
  3. Replace the exhaust pressure control valve if it is determined to be faulty.
  4. Clear the DTC and perform a test drive to ensure the issue is resolved.
  5. If necessary, address any underlying issues such as exhaust leaks or carbon buildup in the valve.

Cost to Fix P0479 Mercedes-Benz

The cost of repairing the exhaust pressure control valve intermittent issue can vary depending on the specific make and model of the Mercedes-Benz vehicle, as well as the location of the repair shop. On average, the parts for this repair can range from $100 to $300, while the labor costs can range from $150 to $300. Overall, the total repair cost for this issue is typically between $250 and $600. It is recommended to consult with a reputable auto repair shop to get a more accurate estimate based on your vehicle's specific needs.

What does this mean?

Tech Notes for P0479 Mercedes-Benz

Check the Exhaust Back Pressure Valve (EBPV) butterfly valve is opening and closing freely and not sticking. If it seems to move freely you can then check the connector and circuit for the EBPV solenoid.

When is the Code Detected?

Problems with either the Exhaust Back Pressure (EBP) Device or the tube between the exhaust manifold and the EBP sensor can be detected during the exhaust back pressure step test, in which the Engine Control Module (ECM) commands and then measures a specific preprogrammed pressure and then measures time for pressure decay during the engine running test.
If the ECM detects an Exhaust Back Pressure (EBP), Engine Oil Temperature (EOT) or Intake Air Temperature (IAT) sensor fault it will disable the exhaust back pressure regulator.

Need more information about the P0479 Mercedes-Benz code?

Need more information on how to fix the P0479 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0479 Mercedes-Benz Code

1. What are common symptoms of OBDII code P0479 (Exhaust Pressure Control Valve Intermittent) in a Mercedes-Benz?

- Common symptoms include reduced engine performance, decreased fuel efficiency, and possible black smoke from the exhaust.

2. What are possible causes of OBDII code P0479 in a Mercedes-Benz?

- Possible causes include a faulty exhaust pressure control valve, damaged wiring or connectors, exhaust leaks, or issues with the exhaust gas recirculation (EGR) system.

3. How can I diagnose the cause of OBDII code P0479 in my Mercedes-Benz?

- Diagnosing the issue may involve visually inspecting the exhaust pressure control valve and its connections, testing the valve for proper operation, checking for exhaust leaks, and using a scan tool to monitor sensor data.

4. Can I drive my Mercedes-Benz with OBDII code P0479?

- It is not recommended to drive your vehicle with OBDII code P0479 as it can lead to further damage and potentially unsafe driving conditions. It is best to address the issue promptly.

5. How can I repair OBDII code P0479 in my Mercedes-Benz?

- Repairing the issue may involve replacing the exhaust pressure control valve, repairing damaged wiring or connectors, fixing exhaust leaks, or addressing any EGR system problems identified during diagnosis.

6. Can I reset OBDII code P0479 in my Mercedes-Benz without fixing the underlying issue?

- While you can clear the code temporarily, it is important to fix the underlying issue causing OBDII code P0479 in order to prevent further damage and ensure proper vehicle operation.

7. How much does it typically cost to repair OBDII code P0479 in a Mercedes-Benz?

- The cost of repairing OBDII code P0479 can vary depending on the specific cause of the issue, but it may range from a few hundred to a few thousand dollars, including parts and labor.

8. Will OBDII code P0479 cause my Mercedes-Benz to fail an emissions test?

- Yes, OBDII code P0479 can cause your vehicle to fail an emissions test due to increased emissions and improper exhaust system operation.

9. Can a DIY enthusiast repair OBDII code P0479 in a Mercedes-Benz?

- While some aspects of diagnosing and repairing OBDII code P0479 may be within reach of a skilled DIY enthusiast, it is recommended to consult with a professional mechanic for proper diagnosis and repair to ensure the issue is resolved correctly.

10. How can I prevent OBDII code P0479 from occurring in my Mercedes-Benz?

- Regular maintenance, such as checking for exhaust leaks, monitoring the EGR system, and addressing any warning signs promptly, can help prevent OBDII code P0479 from occurring in your Mercedes-Benz.

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