My daughters 2010 Sonata has been throwing a OBD II code (P0449) for over a month now. On one week and off the next. She works in a hospital and can't get off to take it right in when its on. Its still under the 5/60 warranty but when she talked to the Hyundai service manager he told her that it would be a $130 charge to diagnose the problem and then addition cost if the warranty does not cover whatever the problem is. Is this right? something smells rotten here. I thought that?s what the warranty was for. In your experience what have you found to be the leading culprit causing the P0449 code? It may be cheaper to take it to the local mechanic or just start throwing new parts in it. I told her to put a piece of black tape over the light and forget about it. Problem with that is that we have emissions test in my state.
AFAIK, the code has to do with the evaporative emissions and an air leak in the fuel system. First thing I would try is to see if she is putting the gas cap on correctly not over-filling the tank. If that does not work, a new gas cap.
I had a similar situation with a car every time I fueled up. Once I stopped at the first stop of the automatic shut off, no more problem, no more CEL. If she is not pumping the gas, find out who is and be sure they don't top off the tank.
As for the dealer charges, $130 seems high to plug in a machine. If it is something NOT under warranty, I can see a charge, but if covered, no charge even for diagnostics. I'd clarify that.
Driver induced problems (if that is the final diagnosis) would not be covered, but emission systems carry a warranty by itself.
Oh, and my Buick dealer plugged in the reader, told me what the problem was and charge me nothing. Maybe you need a better dealer.
This code indicates a vacuum builds up on the fuel tank.
On this vehicle, the most common thing I've seen is that a spider has made a tight web in the canister vent. (Unless the dealer/Hyundai is doing you a favor, spider nests wouldn't be considered a defect in material or workma nship).
The vent is inside the left rear fender well on the filler neck. I typical ly clear these by shooting compressed air into the vent hose/pipe under the car where it goes up into the wheel well, but if you don't have access to that, you can probably remove the fender liner and take off the piece of ho se at the end and clean it out.
No, it isn't right. That's what bumper to bumper warranty is for. Any problem that car develops during normal use is dealer's obligation to diagnose and fix.
No, not quite; be careful using the word "any". Warranty covers defects. Problems can be caused by normal wear or an error, or lack of maintenance by the owner/driver.
This code indicates a vacuum builds up on the fuel tank.
On this vehicle, the most common thing I've seen is that a spider has made a tight web in the canister vent. (Unless the dealer/Hyundai is doing you a favor, spider nests wouldn't be considered a defect in material or workmanship).
The vent is inside the left rear fender well on the filler neck. I typically clear these by shooting compressed air into the vent hose/pipe under the car where it goes up into the wheel well, but if you don't have access to that, you can probably remove the fender liner and take off the piece of hose at the end and clean it out.
P2422 and P0446 are interchangeable. P0449 actually is meant to indicate a n electrical issue, and Hyundai incorrectly uses it to indicate low tank pr essure (vacuum) during normal operation, which is what is intended by P2422 and P0446. Ignore the part about the stuck closed valve; that's an inferr ed code. The system has no idea why the pressure is low, and in fact, the fuel tank pressure sensor could be faulty.
Here's a brief overview of how the evaporative emissions system works:
-- Due to refueling, and expansion and contraction, there must be a way for fuel vapors to leave the tank and be stored.
-- Charcoal has the property that it absorbs fuel vapors; you vehicle is eq uipped with a primary and secondary charcoal canister to do this. The vehi cle is required to have this system and it is required to test itself for l eaks.
-- There are three ports to the charcoal canister: one to the fuel tank, on e to the purge valve on the engine, and one to vent to atmosphere.
-- Vapors are collected via the port to the fuel tank.
-- Vapors are purged via the port the the purge valve. Under appropriate d riving conditions as determined by the fuel management computer, this valve cycles open and closed allowing the fuel vapors to be drawn into the engin e and burned.
-- The vent port has a valve in it called a close valve (or CCV, or vent va lve). This valve exists solely for the purpose of testing the system.
-- The system checks for leaks by closing the purge valve while the close v alve is open until atmospheric pressure is reached inside the fuel tank. T he close valve is then closed and the purge valve cycled until a predetermi ned vacuum is reached in the system. The purge valve is then closed again and the tank pressure (vacuum) is monitored to see how rapidly it changes. Finally, the close valve is reopened to allow the system to return to norm al pressure.
-- If the system cannot reach the predetermined vacuum, code P0455 (large l eak) is set.
-- If the system bleeds off vacuum too quickly, code P0442 or P0456 (small/ very small leak) is set.
-- The self-test will not set P0446, P0449, or P2422; these codes set due t o vacuum build-up during normal operation.
The canister isn't particularly easy to remove-- it's above the rear suspen sion crossmember. You can, however, follow the line from the canister thro ugh the secondary canister toward the left side of the car and the filler n eck area. This is the line/hose in question. If you have compressed air a vailable, disconnect on the vent side of the secondary canister and blow th e air through the vent side of the hose/line. If you don't have access to this, you'll need to pull the left rear fender liner to access the terminus of the vent. It'll be the only thing up there with an open end.
I don't have a picture, and the one I looked at on hmaservice wasn't very g ood.
If I recall correctly, the canister filter will be with the filler neck in this area. Your car, however, may have the filter integrated with the clos e valve. I think they were separate in 2006 but were integrated by the 201
0 model year. Ultimately, I remember this poorly, so I could be wrong.
If you're sure you've successfully cleared whatever was there, then chances are it's a warrantable problem. I've seen a couple cars where the seconda ry canister was restricted.
In the shop, I'd diagnose this with the diagnostic computer attached, graph ing the purge rate and tank pressure. I can then disconnect parts of the c anister vent line starting at the vent end and working toward the canister. When the excessive vacuum is released (during purge), I know it's between the point I just disconnected and the point previously disconnected.
To counter Ed's post about $130 just to hook up a tool, I'll point out it's a little more than that in this case. This could take an hour, depending on where the problem is, and how much of a wait there is for the engine to begin purge each time.
HyundaiTech, got more questions I've got the liner off to see what it looks like in there. See photo at
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Which hose should I check for spider web? A or B? or both? Which one to start with first? I don't have compressed air, would vacuum do? Do I have to take both ends off? Don't want to suck anything out and cause more problems. I see a clamp on hose A, but hose B seems to just be on tight with a plastic tie at one end. How do they come apart? - brute force. It looks as if the plastic vent cap would be mangled with any force to take it off. Any additional assistances would be greatly appreciated.
The canister isn't particularly easy to remove-- it's above the rear suspension crossmember. You can, however, follow the line from the canister through the secondary canister toward the left side of the car and the filler neck area. This is the line/hose in question. If you have compressed air available, disconnect on the vent side of the secondary canister and blow the air through the vent side of the hose/line. If you don't have access to this, you'll need to pull the left rear fender liner to access the terminus of the vent. It'll be the only thing up there with an open end.
I don't have a picture, and the one I looked at on hmaservice wasn't very good.
If I recall correctly, the canister filter will be with the filler neck in this area. Your car, however, may have the filter integrated with the close valve. I think they were separate in 2006 but were integrated by the 2010 model year. Ultimately, I remember this poorly, so I could be wrong.
If you're sure you've successfully cleared whatever was there, then chances are it's a warrantable problem. I've seen a couple cars where the secondary canister was restricted.
In the shop, I'd diagnose this with the diagnostic computer attached, graphing the purge rate and tank pressure. I can then disconnect parts of the canister vent line starting at the vent end and working toward the canister. When the excessive vacuum is released (during purge), I know it's between the point I just disconnected and the point previously disconnected.
To counter Ed's post about $130 just to hook up a tool, I'll point out it's a little more than that in this case. This could take an hour, depending on where the problem is, and how much of a wait there is for the engine to begin purge each time.
B is the area of vent to the atmosphere. Remove the hose and restrictor an d inspect for any blockage in this hose. If there is none, expect your pro blem will be elsewhere and likely warrantable.
It's okay to cut the plastic tie; airtight seal is not necessary at this po int. Once you have this hose removed from the vent/close valve (that thing in the bottom center of the picture), you can probably twist and remove th e restrictor for better access for inspection.
Once the hose is removed from the car, you should be able to remove obstruc tions physically if necessary.
Thanks for the quick reply, you are a great asset to the list. I appreciate all the help. I took off the short B hose and the end restrictor cap , straighten the hose and could see it was clear all the way through. Is there anything to be gained by checking the longer A hose? It doesn't look too difficult to check it out also before I button everything back up.
B is the area of vent to the atmosphere. Remove the hose and restrictor and inspect for any blockage in this hose. If there is none, expect your problem will be elsewhere and likely warrantable.
It's okay to cut the plastic tie; airtight seal is not necessary at this point. Once you have this hose removed from the vent/close valve (that thing in the bottom center of the picture), you can probably twist and remove the restrictor for better access for inspection.
Once the hose is removed from the car, you should be able to remove obstructions physically if necessary.
It can't hurt, but I doubt you'll find anything there. Apparently, your car is one of the vehicles after the design change that added the restrictor on the end. I think I've never seen a spider web inside one of them.
I took the car in to the dealer today and it was fixed under warranty. The tech wrote in the text that it was a clogged filter, the part # listed was
31421-0A000 CANISTER-AUX . Makes me wonder why a clogged filter is covered under warranty but a clogged hose (spider web) would not be. Or is he just being nice to me and covering it anyway? Another question is if this is the famous "FUEL TANK AIR FILTER" that our owners manual says we should replace every 2-3 years? Thanks again, HyundaiTech
It can't hurt, but I doubt you'll find anything there. Apparently, your car is one of the vehicles after the design change that added the restrictor on the end. I think I've never seen a spider web inside one of them.
If the filter is designed not to clog, it would be a manufacturing defect and covered. If a spider builds a web or nest, it is caused by an environment beyond the control of the manufacturer, thus, not covered.
The emissions system is covered not because the car makers are nice guys, but because the Feds demand that they do for some length of time. Some states may add on too.
Federal Emissions Warranty ? Under the Federal Emissions Warranty, all emissions related parts are covered for 2 years or 24,000 miles*, with the catalytic converter and engine control unit (the computer) covered for 8 years or 80,000 miles*. These Federal Emissions Warranty provisions cover light-duty vehicles up to 8500 pounds Gross Vehicle Weight Rating (GVWR).
This is not a filter. It is an auxiliary charcoal canister. The cause for the code was a blockage or restriction in the canister. Typically, this is caused by charcoal pellets coming loose inside the cansiter.
Why the engineers felt it necessary to have two canisters, I've no idea.
Thanks, HyundaiTech. Could you comment on the "FUEL TANK AIR FILTER" that our owners manual says we should replace every 2-3 years?
This is not a filter. It is an auxiliary charcoal canister. The cause for the code was a blockage or restriction in the canister. Typically, this is caused by charcoal pellets coming loose inside the cansiter.
Why the engineers felt it necessary to have two canisters, I've no idea.
On your particular vehicle, I believe the evaporative emissions filter (or fuel tank air filter, as Hyundai likes to call it) is part of the canister close valve, so it's not really designed to be maintained anyway.
I've seen a few vehicles with these filters clogged, but it really isn't th at frequent. For most people, it's more cost effective to wait until a pro blem occurs (typically check engine lamp or difficulty refueling) and pay f or diagnosis and repair, rather than replace the filter per the maintenance schedule.
The only exception I'd make is someone that drives in very dusty conditions .
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