How To Test Purge Valve With Multimeter

If you’re a car enthusiast who loves to work on their vehicles, testing the purge valve is probably something that interests you. Knowing how to test this important part of an engine’s emission system can help keep it running smoothly and efficiently – plus, it’s satisfying to take care of yourself! However, testing a purge valve may seem intimidating if this is your first time attempting such a project. But don’t worry; it’s simpler than you might think! Using just a multimeter, we’ll guide you through the process step-by-step so that no matter what type of car or gauge size, you can learn how to test the purge valve from start to finish.

How To Test Purge Valve With Multimeter

What Is A Purge Valve?

A purge valve is a vital part of an Evaporative Emission Control System or EVAP. It helps your vehicle run more efficiently and reduces emissions by collecting fuel vapours in a charcoal canister and releasing them into the engine when needed. The Powertrain Control Module (PCM) determines when to open and close the valve to provide enough fuel for combustion. This secondary fuel source then burns off any pollutants before they enter the atmosphere, making it an essential component in environmental protection. With regular maintenance and occasional replacement, your purge valve can help keep your car running cleanly and smoothly for years to come.

What Are The Benefits Of A Purge Valve?

The benefits of having a properly functioning purge valve are numerous. Capturing and reusing fuel vapours can help improve your car’s fuel efficiency. This leads to fewer trips to the pump and more money saved over time. Additionally, fewer pollutants escaping from your vehicle helps reduce your car’s carbon footprint, contributing to a healthier environment for all. Finally, it extends the life of other components in the EVAP system by preventing them from being exposed to too much pressure or heat.

How To Test Purge Valve With Multimeter

Using a multimeter, you can quickly test the purge valve. To begin, switch your multimeter to Ohms mode. Measure the resistance between the power terminals of the purge valve. If the reading is less than 15 ohms or more than 30 ohms, the purge valve has failed and should be replaced as soon as possible.

Required tools:

  • Multimeter
  • Flashlight

Testing Resistance:

  • Disconnect the purge valve from the car.
  • Set your multimeter to Ohms and turn it on.
  • Locate the two pins on the purge valve and place the probes of your multimeter on them. Make sure you have a good connection with the pins and that no corrosion or debris is blocking them.
  • Evaluate the results shown on your multimeter display. Depending on the model of your car, a good purge valve should have a resistance of 15 to 30 ohms. If you are getting any other readings, this may indicate that your purge valve needs to be replaced.
  • Use a flashlight to check if any physical damage is present in or around the purge valve. If you notice any, then replace the purge valve.

Testing the purge valve with a multimeter is a quick and easy way to determine whether or not the purge valve needs to be replaced. These steps can help you save time and money, ensuring your car runs optimally.

Testing Continuity :

  • Disconnect the purge valve from the car. Inspect the purge valve for any visible signs of damage, such as corrosion or a loose connection. Use a flashlight to get better visibility if necessary.
  • Set your multimeter to continuity mode, which will tell you whether the electrical resistance is within functional limits or not.
  • Position the multimeter probes on the terminals of the purge valve and check that there is continuity in both directions when testing for open/short circuit conditions (resistance should remain constant throughout).
  • Evaluate results: A beeping noise indicating continuity between two points means that the purge valve is functioning correctly; otherwise, it needs replacement as soon as possible! If further assistance is required, contact your local car mechanic for additional help.

Following these simple steps, you can quickly check whether your purge valve needs replacement! If further assistance is required, contact a qualified automotive technician for additional help.

Common Problems With The Purge Valve:


The purge valve can sometimes become clogged due to dust, debris, and other contaminants in the air. This can disrupt the airflow and cause performance issues.


Over time, certain environmental chemicals may corrode parts of the purge valve, leading to malfunctioning or even failure of the device.

Pressure Drop:

A variety of factors, such as a blocked filter, loose fasteners, or worn gaskets, could cause a decrease in pressure within the purge valve. It is essential to regularly check these components for damage and wear to ensure proper performance from the purge valve.


Poorly sealed connections or worn gaskets can cause leaks in the purge valve, leading to a loss of pressure and efficiency. Regular maintenance should be carried out to minimize the risk of such leaks.


If not properly maintained, the purge valve may become contaminated with dirt and other particles, leading to poor performance or failure of the device. Regular cleaning is necessary to prevent this from happening.

Poorly Sealed Connections:

Without proper sealing, air and fuel will leak out of the purge valve instead of being directed into the engine, where it is needed for optimal performance. This could lead to reduced fuel economy and decreased power output from the vehicle’s engine.

Faulty Sensors:

Several sensors control the purge valve, which can sometimes become faulty and cause performance issues with the device. Regularly testing these components is essential to ensure that they are working correctly.

Clogging of the Hose:

If the hose connected to the purge valve becomes clogged, it can prevent the proper flow of air into or out of the engine, leading to reduced performance and fuel economy. Inspecting this component for signs of wear or damage regularly is necessary.

Worn Gaskets:

The gaskets between various parts of the purge valve may become worn with time, allowing air and fuel to leak out instead of being used in the engine. This can lead to poor performance and a decrease in fuel economy.

Faulty Solenoid:

The solenoid connected to the purge valve controls when air or fuel enters the engine. If it becomes faulty, this could lead to reduced performance and efficiency from the vehicle’s engine. Regular maintenance and testing of this component are essential for optimal purge valve operation.

Regular inspection and maintenance of the purge valve are essential for achieving optimal performance from your vehicle’s engine. By regularly checking for any signs of wear or damage and ensuring that all components are functioning correctly, you can ensure that your car will be running at its best.

Frequently Asked Questions:

What are the symptoms of a faulty purge valve?

A faulty purge valve can cause various symptoms, such as engine hesitation, rough idling and increased fuel consumption. Other signs include a jerking feeling when the vehicle accelerates, backfires and an illuminated check engine light on the dashboard.

What parts are associated with a purge valve?

The purge valve is part of the evaporative emission system (EVAP), which helps reduce hydrocarbon emissions from vehicles. The EVAP system includes components such as the vapour canister, fuel tank cap, charcoal canister and vent solenoid.

What are some common causes of a faulty purge valve?

A faulty or broken purge valve can be caused by various factors, including age, corrosion and damage due to debris or oil. The EVAP system may also become clogged by dirt or contaminants, preventing the purge valve from functioning correctly.

How do I know if my vehicle needs new parts for its EVAP system?

If you experience any of the symptoms mentioned above, your vehicle likely needs new components for its EVAP system. You should take your car to an experienced technician who can thoroughly inspect and diagnose the problem.

Can I replace the purge valve myself?

In some cases, you may be able to replace the purge valve yourself; however, this is not recommended unless you have adequate mechanical experience and access to the necessary tools. If in doubt, it’s best to have a professional technician do the job.


Finally, testing a purge valve with a multimeter is relatively simple. The steps outlined above will help you obtain accurate readings and identify any problems. Always follow the manufacturer’s instructions when working with electrical components and take the necessary precautions. You should be able to diagnose any problems with your purge valve quickly and efficiently if you have some patience.

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