Engine-Codes.com
Engine-Codes – Generic – P0479

P0479 Code - Exhaust Pressure Control Valve Intermittent

Quick Answer

The P0479 code indicates a problem with the Exhaust Pressure Control Valve (EPCV) that is intermittent. Common causes include Faulty Exhaust Pressure Control Valve, Wiring or connector issues, Malfunctioning Engine Control Module. 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 indicates Exhaust Pressure Control Valve Intermittent.
Common causes
Common causes include Faulty Exhaust Pressure Control Valve, Wiring or connector issues, Malfunctioning Engine Control Module.
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 13, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0479 Description

The P0479 code indicates a problem with the Exhaust Pressure Control Valve (EPCV) that is intermittent. The EPCV is a crucial component of the vehicle's exhaust system, responsible for regulating the pressure in the exhaust system. When this valve malfunctions or operates intermittently, it can lead to a variety of issues that affect the vehicle's performance and emissions.

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

Common Causes of P0479

  1. Faulty Exhaust Pressure Control Valve.
  2. Wiring or connector issues.
  3. Malfunctioning Engine Control Module.
  4. Sensor problems.
  5. Exhaust system leaks or blockages.

Symptoms of P0479

  1. Check engine light illuminated on the dashboard.
  2. Decreased engine performance or power.
  3. Increased fuel consumption.
  4. Rough idling or stalling.
  5. Failed emissions test.

How to Fix P0479

  1. Use a diagnostic scanner to retrieve the trouble codes and verify the P0479 code for the Exhaust Pressure Control Valve Intermittent.
  2. Inspect the EPCV, wiring, connectors, and sensors for any visible damage or corrosion.
  3. Test the EPCV and related components using a multimeter to check for proper operation.
  4. Replace the faulty EPCV, repair any damaged wiring or connectors, and reset the ECM to clear the trouble codes.
  5. Perform a test drive to ensure the issue is resolved and the check engine light does not reappear.

Cost to Fix P0479

The typical repair costs for addressing the P0479 code can vary depending on the specific cause of the issue and the vehicle's make and model. In general, replacing the Exhaust Pressure Control Valve and addressing any related wiring or sensor issues can range from $200 to $500, including parts and labor. However, it is essential to note that diagnosis time and labor rates at auto repair shops can vary significantly, with hourly rates typically ranging from $80 to $150. It is advisable to consult with a local auto repair shop for a more accurate estimate based on the specific circumstances.

What does this mean?

Tech Notes for P0479

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 code?

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

Need Help with the Code?

Get the P0479 code diagnosed by a professional: Find a repair shop in your area

Code P0479 Information for Specific Makes

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 Code

No Frequently Asked Questions about P0479 Code found.

Discuss the causes and fixes for P0479 OBDII Code

Submit a New Comment

Code P0479 comments

No comments found for this page.