2016 Hyundai Sante Fe

John Owner/Technician British Columbia Posted   Latest  
Resolved
Driveability
2016 Hyundai Santa Fe Sport 2.0T 2.0L (A) 6-spd (A6LF2) — 5XYZUDLA1GG377271
P0449 — EVAP System Vent Valve Control Circuit/Open

Hi guys, we have this car with P0449 code, Evap vent valve control circuit. We have removed the valve and tested on bench, tests ok. We installed new aftermarket valve just in case something sticking intermittently. Still the same. The customer is also complaining of hard to fill tank at gas station. We have cleared the code and ran the in bay test for the vent valve, it passes in the bay. We then drive the car and the code comes back within 5 minutes. The light will come on on the second road test. We have taken the evap lines off and blew through them but nothing comes out except air. We have tested for power and ground at the valve and it is ok except we noticed on the ground side with the connector disconnected we have power bleeding over, enough to light a test light but not enough to light a halogen bulb. Maybe this is ok????. We are suspecting the cannister may be at fault but we have no way of testing it and a new one is $700 without the vent valve. Has anyone ran into this before? Thanks in advance, John

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Eric Mechanic
North Carolina
Eric
 

Can you blow through the canister with little resistance?

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John Owner/Technician
British Columbia
John
 

Yes we can blow through it with little resistance. There was a little oily substance came out.

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John Technician
Ontario
John
 

Does the scantool have bi direction control of the vent valve? Code is for a circuit fault.. That being said, hard to fill, did you check the the vent filter or lines for blockage? Seems like air can't get out

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John Owner/Technician
British Columbia
John
 

Yes we can control the valve with the scan tool and it opens and closes ok, there is no restrictions in any of the lines or canister.

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Harm Technician
Ontario
Harm
 

try testing to valve under a load of either vacuum or pressure. likely sticks. Not a fan of aftermarket valves

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Rod Diagnostician
California
Rod
 

Have you verified proper operation of the pressure sensor? I know the code says circuit, but we do not know what they were thinking when they wrote that. So with that in mind , if the valve is commanded closed and the pcm looks for a change in tank pressure and the pressure sensor is not shorted or open but it is out of range could that trigger that code? We don't know for sure , thus my…

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James Instructor
New Jersey
James
 

Fuel tank pressure sensor is reading an underpressure during drive cycle. Sounds like vent concern. Make sure you can blow through fresh air side system(after canistor)…spider webs or lack of filter maintenance is likely. If you can, monitor FTPS PID voltage key on and compare to drive cycle during no purge. May help to pinpoint this.

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Rod Diagnostician
California
Rod
 

So “circuit” on that code does not necessarily mean “electrical” circuit correct?

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John Owner/Technician
British Columbia
John
 

I don't think so because the circuit is working ok. Has good voltage and the computer is grounding the circuit ok.

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Brian Diagnostician
California
Brian
 

My money is on a restricted filter for the vent circuit

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John Owner/Technician
British Columbia
John
 

Brian you were right on. We pulled the left rear inner fender to access the filler neck and breather. The breather pipe is attached to the filler neck and there is a filter at the top. We blew air through from the bottom of the breather hose and half a dozen little spiders and nests blew out. We reassembled, cleared the code and road tested, all good.

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Lonny Diagnostician
Florida
Lonny
 

Should not Have voltage showing on control side of circuit. Test wiring back to pcm.

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Don Owner/Technician
Texas
Don
 

You will have bias voltage. That is what is used by the computer to do the test.

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John Owner/Technician
British Columbia
John
 

Thanks for the info.

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John Owner/Technician
British Columbia
John Resolution
 

Thanks for help guys, Brian was correct with breather for vent, it was partially plug with several spiders and nests blocking it. cleaned it out and all is good. Cheers guys. John

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