[Surfer_Sandman]

Hi All,
I'm a proud owner of a 2010 Accent GS, and it's been good to me except a few reoccurring issues. The one I'm having issues with today is the Check Engine Light for my EVAP system. I've replaced the gas cap, purge valve and hoses. Problem is that the CEL keeps coming back on for the same error. I have no modifications and the crazy thing is that it will go away randomly. Then it comes back and hangs around a while. Since I know the code, I've been ignoring it, but I am now at 104k miles and I want to be sure I don't miss some other issue that comes up.

Any ideas?

Thanks,

PS. All parts have been OEM Hyundai replacement parts.

 

[rustyaccent]

What code are you getting? Did you use your scanner to pull up the results of the EVAP monitor tests the ECM runs (if it has that capability)?

When you replaced the original purge control valve, did you inspect the connector and wiring harness for signs of damage?

Are there any noticeable issues with how the car runs (e.g. hard to start, rough idle etc.)?

 

[sbr711]

Hi All,
I'm a proud owner of a 2010 Accent GS, and it's been good to me except a few reoccurring issues. The one I'm having issues with today is the Check Engine Light for my EVAP system. I've replaced the gas cap, purge valve and hoses. Problem is that the CEL keeps coming back on for the same error. I have no modifications and the crazy thing is that it will go away randomly. Then it comes back and hangs around a while. Since I know the code, I've been ignoring it, but I am now at 104k miles and I want to be sure I don't miss some other issue that comes up.

Any ideas?
Got to know the code to have idea,, a bunch of EVAP related DTC in the menu... I can pick a part, might cost money, and be wrong guess too,, code tell me which circuit we see to have fault..

Got code yet ?

Thanks,

PS. All parts have been OEM Hyundai replacement parts.
What parts ?? What DTC we attempting to remedy??

Help me help you,, got DTC in proper "Pxxxx" format ??

 

[Surfer_Sandman]

I'm getting the "P0496 - Powertrain code." The car runs fine, and when I cleared it most recently it actually seemed to idle a little smoother. (could be my imagination)
When I originally replaced the purge valve I didn't notice any wear on the wires. The problem did go away for a while and then came back maybe 6 months later. That's when I found my hose was cracked. (Completely missed by the dealership who charged me $95 diagnostic too tell me what I already knew.)

The it was good for a while again. I'm just not sure how often these things are really supposed to go bad. Right before I hit 100k miles I took it into the dealer and they did do a EVAP test and everythign looked sealed. So maybe you are right and this is a wiring issue.

Also I'm using the Torque app paired with a Bluetooth OBDII reader.

 

[sbr711]

0496 in the Hyundai DTC menu reflects on Purge having High Flow.. to me thta would imply that the purge is hanging open and drawing off the canister,, with the PCM seeing voltage fluctuation from Tank Pressure Sensor when PCM knows it is not commanding Purge flow..

With engine running, see if Purge is indeed sticking/stuck open and draw vacuum on chassis side of valve with engine at idle and connector unplugged.. you can also pull hose off with connector plugged in and see if at some point it start doing a POP-POP-POP-POP as PCM duty cycle purge..

 

[Surfer_Sandman]

0496 in the Hyundai DTC menu reflects on Purge having High Flow.. to me thta would imply that the purge is hanging open and drawing off the canister,, with the PCM seeing voltage fluctuation from Tank Pressure Sensor when PCM knows it is not commanding Purge flow..

With engine running, see if Purge is indeed sticking/stuck open and draw vacuum on chassis side of valve with engine at idle and connector unplugged.. you can also pull hose off with connector plugged in and see if at some point it start doing a POP-POP-POP-POP as PCM duty cycle purge..

Thanks SBR, I'll try that out tomorrow and report back.

 

[Surfer_Sandman]

I forgot to mention. The one issue that I also get with this. When I fill my tank at a gas station, the car wants to stall out. I have to rev it to keep it from stalling. After a short amount of time the idle seems to level out and it's fine again.
Sorry for the long delay getting back to you. I have been super busy, but now I need to fix this as I'm listing my car for sale. Need the 4 doors of the 2006 Mazda 3 I'm getting. Basically a swap cause family.

 

[grcauto]

I forgot to mention. The one issue that I also get with this. When I fill my tank at a gas station, the car wants to stall out. I have to rev it to keep it from stalling. After a short amount of time the idle seems to level out and it's fine again.
Sorry for the long delay getting back to you. I have been super busy, but now I need to fix this as I'm listing my car for sale. Need the 4 doors of the 2006 Mazda 3 I'm getting. Basically a swap cause family.

I assume the vehicle is off during the fill up and this happens on the startup.
The purge valve is sticking open and adding fuel vapors into the intake when it shouldn't. Can you smell fuel from inside the car or around the canister? If so the canister has raw fuel in it and will need replacing. That's not your purge problem but canisters don't do well when they are fuel logged.

 

[Surfer_Sandman]

Thank you again for all the help. Here is the latest:

With the hose disconnected from the purge valve there is vacuum. Both with the sensor connected and disconnected.
When I have the hose disconnected and the sensor connected I got the pop pop pop sounds.

So I think the Purge Valve is stuck open. If that's the case I need to replace it again right?
I don't smell any gas in the cabin or in the engine compartment.

Lastly in the Torque app, the EvapP Pa is flat with the hose disconnected from the purge valve. Normally when I'm driving around it's all over the place. but then flattens out sometimes then is all over the place.

I appreciate any more feedback you can provide.
Thanks

 

[grcauto]

Thank you again for all the help. Here is the latest:

With the hose disconnected from the purge valve there is vacuum. Both with the sensor connected and disconnected.
When I have the hose disconnected and the sensor connected I got the pop pop pop sounds.

So I think the Purge Valve is stuck open. If that's the case I need to replace it again right?
I don't smell any gas in the cabin or in the engine compartment.

Lastly in the Torque app, the EvapP Pa is flat with the hose disconnected from the purge valve. Normally when I'm driving around it's all over the place. but then flattens out sometimes then is all over the place.

I appreciate any more feedback you can provide.
Thanks

I think the canister is back by the tank. Usually you will smell the fuel regardless. Don't sound like it's water logged. Make that fuel logged.

Good luck.

 

[Surfer_Sandman]

So given my symptoms, it seems to be the canister. I just don't want to spend $100 and then still have the issue. But it is one part I've not replaced and I do have 106k miles on it.
I'll get a replacement and update the forum.
Thanks

 

[Red Raspberry]

Unless the canister is physically damaged I don't think it could cause a high flow rate P0496. Somewhere there is a leak.


Here's some discussion of the code. https://www.yourmechanic.com/articl...ing-a-non-purge-condition-by-valerie-johnston
https://www.justanswer.com/hyundai/akk8j-2009-hyundai-accent-getting-p0496-so-tested.html



And a trouble shooting guide. https://f01.justanswer.com/jhook1398/88386887-0fd9-4374-a800-ac4f8fb81ab3_1.pdf

 

[grcauto]

So given my symptoms, it seems to be the canister. I just don't want to spend $100 and then still have the issue. But it is one part I've not replaced and I do have 106k miles on it.
I'll get a replacement and update the forum.
Thanks

NO, NO, NO...your symptoms and codes point to the purge valve not the canister. I was saying the canister will need to be replaced IF IT FLOODED with fuel. Yours didn't.

 

[Surfer_Sandman]

Ah, okay. So when I went under the car to inspect the canister I noticed there is another purge valve attached to the canister. Could that valve be bad? I haven't replaced it yet like I have the one in the engine compartment. I'll also look for a leak, but I did inspect the hoses I can see and they look like they are in good shape.

As for the troubleshooting guide... unfortunately I don't fully understand it. I am just a shade tree mechanic and when it gets to some of these steps I'm a little lost.
I need visuals :/
Anyway I'll see if I can decipher it and post back here.

 

[grcauto]

Ah, okay. So when I went under the car to inspect the canister I noticed there is another purge valve attached to the canister. Could that valve be bad? I haven't replaced it yet like I have the one in the engine compartment. I'll also look for a leak, but I did inspect the hoses I can see and they look like they are in good shape.

As for the troubleshooting guide... unfortunately I don't fully understand it. I am just a shade tree mechanic and when it gets to some of these steps I'm a little lost.
I need visuals :/
Anyway I'll see if I can decipher it and post back here.

Is the canister at the back of the tank? The valve there is the close valve. The purge valve is up in the engine and has tubes coming from the canister and going into intake.

The testing procedures are known as trouble trees. An appropriate name as they will get you into trouble more than not. The best thing is to read and glean as much as you can and try and get a handle on how the system works and use the diagrams (wiring, plumbing, vacuum) to test. A good scan tool is a must if you are a shop but not necessary if you have time and want to save money. Do you know anyone that has a scan tool? Not a code reader but a good scan tool.

 

[sbr711]

I be curious to know if canister has exploded internally and random pellet come up the line and foul the purge valve to create leak with purge flow when PCM knows we not commanding flow..

Remove lines from canister and see if we find loose pellets

 

[Surfer_Sandman]

What would cause the canister to explode though?

 

[Surfer_Sandman]

Okay, so Purge Valve is in the Engine and that can be stuck open causing high flow? The close valve near the canister failing would cause a low flow code? Or if the close valve fails does it fail open?

 

[grcauto]

Your code is for the purge valve. You can get a factory service manual on ebay for about 40 bucks that will go a long way for you to learn different systems and really helps in repairs.

 

[Surfer_Sandman]

Awesome. Thanks again for all the help. I really do need to buy a service manual but I wasn't aware you could buy one made by Hyundai.