P0496 – Meaning, Causes, Symptoms, & Fixes

Code P0496 Definition

EVAP Flow During a Non-Purge Condition

What Does P0496 Mean?

The Evaporative Emission Control (EVAP) System seals the fuel system of the vehicle in order to prevent fuel vapors from the fuel tank and fuel system from escaping into the atmosphere. This is important because fuel vapors contain a variety of hydrocarbons. Hydrocarbons form smog when they react with air and sunlight. Gasoline evaporates very quickly, so if the fuel system is open to the atmosphere a vehicle can pollute 24 hours per day without even being turned on. These uncontrolled evaporative emissions account for as much as 20% of the pollution produced by a vehicle! When trouble code P0496 is set, it means that there is an issue with the purge flow in the EVAP system. Specifically, the Evaporative system is purging fuel vapors when it shouldn’t be. 

What Are The Symptoms Of P0496?

There may not be any noticeable driving issues with your vehicle, but your engine could be running rich which could cause Catalytic Converter damage. It may also be hard to start the vehicle.

What Is The Cause Of P0496?

  • Faulty EVAP Purge Volume Control Valve (most common)
  • Faulty EVAP pressure sensor
  • Leaking EVAP system hose
  • Poor electrical connections
  • Leaking Charcoal Canister

How Serious Is Code P0496? – Low

Although there are no apparent driving issues with this trouble code, it should still be addressed as soon as possible so that there is no damage to the catalytic converter.

Code P0496 Common Diagnosis Mistakes

Replacing the EVAP Purge Volume Control Valve before checking to see if it is leaking.

Tools Needed to Diagnosis Code P0496

    • FIXD
    • Digital multimeter
    • Basic hand tools
    • Vacuum gauge (optional)
    • EVAP smoke machine leak checker
    • Hand vacuum pump
    • Vehicle specific service manual

How To Diagnosis And Repair Code P0496:

Difficulty of Diagnosis and Repair – 2 out of 5

  1. Reset the Check Engine Light to see if the Check Engine Light returns in the future.
  2. If the code returns, test the Purge Volume Control Valve for a Stuck Open condition. With the key and engine off, remove the hose going to the Purge Volume Control Valve coming from the fuel tank and unplug the electrical connector to the valve. (performing this test may set another code if it does, clear the code and disregard it until after the test is completed and the vehicle is put back together). Now, start the engine and use either a vacuum gauge or your finger to see if the vacuum is coming out of the Purge Volume Control Valve where you removed the hose. If there is a vacuum, then the Purge Volume Control Valve is leaking and needs to be replaced. If there is no vacuum you could still have an intermittent failure of the Purge Volume Control Valve or another EVAP system issue. Continue the diagnosis on the next step.
  3. Perform an EVAP system leak check: Pinch off the vent tube to the EVAP Vent Control Valve. Pressurize the EVAP system with an EVAP smoke machine leak checker. Check to see if you see any smoke leaking out from any hoses or seals. If there are any leaks, repair leaks and check to see if the concern is resolved.
  4. If you find no leaks, then grab your digital multimeter and back probe the EVAP Pressure sensor signal wire. Remove the EVAP Pressure Sensor from the Charcoal Canister or disconnect the hose going to it and apply a slight amount of pressure to the sensor using the pressure hand pump. You should see the voltage change as you do this. (consult the service manual for your vehicles spec on what this voltage should be) If it is not in spec, replace the EVAP pressure sensor.
  5. If the concern persists after these checks, it may be time to take the vehicle to the shop to have it diagnosed.

Estimated Cost of Repair

For error code P0496, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.

  • EVAP Purge Volume Control Valve $150-$200
  • EVAP Line $20-$100
  • EVAP Pressure Sensor $280-$330

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Comments 27

john smith

July 20, 2018

It was just my gas cap

Kalon Wright

September 22, 2019

meaning what, that gas cap needed to be replaced?

James Price

July 27, 2018

Yes it was my purge valve solenoid sensor valve $32 bucks thank God for my FIXD tool

FIXD Marketing

July 30, 2018

Hi James!

That’s great to hear, I’m glad you’re happy with your FIXD sensor! Don’t forget to come back to the FIXD blog for any additional information about your Diagnostic Trouble Codes.

The FIXD Team

David Carey

September 9, 2018

Hi James
Was the purge solenoid senser valve difficult
To repair, and where is it located
Thanks
Dave

Alisha P

October 19, 2018

Easy! YouTube it. I did. Mines 25 bucks… 3 clips and top of engine towards the back on my chevy cruze

Ron Borges

August 19, 2019

Where is the canister purge valve located on a 3.6 equinox

Johnny boy

August 29, 2019

I have a 2007 Acadia but I can’t find the omission purge part on the engine

James Reid

September 24, 2018

Checked purge solenoid,, was not the problem. Replaced with new solenoid and nothing changed,,, Could old solenoid have issue although testing it was same as new solenoid?
Sending car to shop to have checked.

Alisha

October 19, 2018

Its easy normally as the top of the engine. YouTube it. I did in my Cruze.. 3 clips. Fixing it tomo for 25 bucks!

Chasity

May 23, 2019

Ok once you replace the purge valve how long did it take for the check engine light to go off

Dw

June 19, 2019

My gas cap needs to be sound three times to make sure it is tightened

pretressia

December 27, 2018

I replaced my solenoid valve but my check engine light is still on and my remote start doesn’t work. Any suggestions?

Rudy

January 2, 2019

My car does the same thing. Did you found out what it was. Thanks

T

July 5, 2019

In most vehicles if your check engine light is on remote start will not function.

Jacob

February 5, 2019

I have a 2013 Cadillac with the same issue I changed the one on top of the motor that gone bad but there’s also one in the back that normally go
es bad too close to the gas tank you can check the purge by blowing into it if air goes through that means it’s bad if it doesn’t is good

Frank Myers

February 20, 2019

Same problem, changed both,on engine and by under by gas cap line and new gas cap.I clear the check engine light and the remote start works for a week or two. 2013 Chevy Silverado LT 1500

Janell

September 5, 2019

P496. P451. P456.
The first one came up twice with pd at the end of the second one. Car would have rough start or stop giving any gas to move while driving, I think something is plugged

Glenda McClendon

December 30, 2018

My son replaced his fuel pump in his 2006 tahoe he also put in new spark plugs it was starting up but now it won’t if he let it sit for a minute it will start what could be the problem

Serenity Klaysmat

January 15, 2019

Have this code on my 03 chevy silverado 1500 5.3. I’ve replaced the purge valve/senloid, fuel pressure sensor, and the canister connected to the purge as mine was cracked. My truck is has major leaking gas from canister. I also have the code p0101 MAF sensor still on board. What is going on?

Richard Sumlin

February 4, 2019

I changed the Purge valve , now does the computer reset itself or do I have to plug in and reset it manually

Steve

March 23, 2019

Reset it manually.

Isa

September 14, 2019

Go to FIXD and press ,”Clear check engine”

Jarrid

May 8, 2019

Hello my 2015 Chevy Cruze is misfire once or twice after i fuel up and wants to stall when idling has anyone ever had this problem?

sheila scott

September 11, 2019

Yes my car did the same thing, it would feel like it was going to die sitting at the light. SO I recently found out it was the valve cover crank shaft I think is what its called. , its the piece on top of the engine right on top of spark plugs, there to the right is a circle that peace is what cause the car to want to stall. Found out its under warranty 10yrs or 120k miles, SO I just fixed it but today I have a new code p0469 says I need to replace purge ?? silonde sorry cant spell. Get rid of the car they suck. I have a 2015 and its at 113 k miles I commute daily good luck

Pat

May 22, 2019

How can one reste the alarm after replacing the vale without a OCD II

Nicholas Starks

June 27, 2019

It’s not the selenoid valve on my 2012 Cruze. The vacuum leak is from the hose they attaches to the left side of it. What is that?

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