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Summary
  • Diagnostic trouble code (DTC) P0308 stands for “Evaporative Emission System Purge Control Valve Circuit Open.” This means that the powertrain control module (PCM) has detected a problem with the purge valve circuit.
  • Common causes of the P0308 code include a faulty purge valve, circuit problems, and a malfunctioning PCM.
  • The symptoms that often accompany the P0308 code include an illuminated check engine light, reduced fuel economy, and a noticeable fuel odor.

On-board diagnostic (OBD) codes are designed to help mechanics and vehicle owners like you identify possible issues with your vehicle. But before attempting any fixes to resolve the codes retrieved by your scan tool, it’s important to know exactly what they mean.

Code P0444 is one of many trouble codes that may be logged and retrieved from the OBD system. Here is some basic information that may help you understand what getting this code may mean for your vehicle.

What Does the P0444 Code Mean?

Diagnostic trouble code (DTC) P0444 stands for “Evaporative Emission System Purge Control Valve Circuit Open.” This code is logged when the PCM detects a problem with the purge valve circuit.

See also  P0443 Code: Evaporative Emission System Purge Control Valve "A" Circuit

On vehicles with an Evaporative Emission Control System (EVAP), fuel vapors from the gas tank are stored in a charcoal canister. Under precise operating conditions, the PCM opens the purge valve to draw the vapors from the canister into the engine’s intake manifold. The vapors are then burned as part of the normal combustion process.

Purge Valve in Isolated Gray Background
A faulty purge valve can cause the P0444 Code.

The PCM monitors the voltage to the purge control valve and detects any voltage changes within it. If it notices a problem with the purge valve’s circuit, it logs error code P0444.

Depending on the severity of the problem, related error codes may also be stored with this DTC. Code P0444 is very similar to error codes P0443 and P0445.

Read our discussion about the EVAP system, how it works, and its evolution to fully understand codes like P0444.

Note: The definition of code P0444 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Possible Causes of the P0444 Code?

P0444 is a generic code, so it can have several triggers. Here are the most common:

  • A faulty purge valve
  • Circuit problems, such as damaged wires or loose connections
  • PCM malfunction

What are the Common Symptoms of the P0444 Code?

You may notice the following symptoms if you drive a vehicle that has set a P0444 trouble code:

  • Illuminated check engine light
  • Reduced fuel economy
  • Noticeable fuel odor in some cases
  • Engine may idle rough, hesitate, or stall in some cases
  • Sometimes there are no adverse conditions exhibited besides the check engine light
See also  What Does a Vapor Canister Do?

How to Diagnose the P0444 Code

Error code P0444 is a generic code that may be set across several makes and models. However, this does not mean that there is a one-size-fits-all approach to diagnosing its underlying cause. The steps for troubleshooting this code will vary depending on your vehicle’s make and model.

Check out the video below to get an idea of what the diagnostic process for this code might involve:

How to Fix the P0444 Code

P0444 may share similar triggers and symptoms with other fault codes. However, that does not mean that they share repair steps as well. All vehicles are different, so make sure to refer to a factory repair guide that is specific to your car.

If you’re considering troubleshooting this code on your own, it’s a good idea to refresh your auto repair knowledge before attempting any fixes. Always consult the vehicle repair manual or an online repair database to learn the appropriate diagnostic and repair procedures for this code. Alternatively, you may leave this job to a professional.

See also  P0496 Code: EVAP Flow During a Non-Purge Condition

Where to Get a New Purge Valve for Your Vehicle

A faulty purge valve may cause your vehicle to suffer from poor fuel economy and frequent ignition troubles. To restore its performance and extend its service life, it’s best to consult a mechanic and replace worn-out components as needed. Thankfully, CarParts.com has a wide array of high-quality purge valves for you to choose from.

We trust the quality of our products because we source them from the most trusted manufacturers in the industry. This ensures you get parts that are worth your money and can last as long as your vehicle’s lifespan. Not only that, but we also offer 60-day returns and a lifetime replacement guarantee.

Shop online, and get the best deals today!

About The Authors
Written By Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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Daniel tadesse

I have hyundai atos 2001 car when I start engine rpm is high and then gradually decrease z rpm when you select z gear shift and then again high what is possible solution to solve z prblem

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