camgci

A while back the check engine light came on and indicated a P0449 code. After doing a search here I went ahead and changed the solenoid valve and erased the code. Three or four starts later light came back on and I was advised to change the purge valve.
Changed that, did no good, light still came back on.
Then last time I filled the car with gas it backed up gas during filling continuously until full. I remember someone else having the same issue but could not find the thread. 2006 C6. Anyone have any ideas?
Thanks.

FortMorganAl

P0449 is the vent valve circuit. P0443 is the purge valve. If you have 49 then there is no problem with the purge valve. If you have 43 then there is no problem with the vent valve. Your issue is most likely a plugged or crimped hose leading to the vent solenoid or wiring to the vent solenoid. Are you getting power to the vent solenoid? With the clip on the top, the left pin should have 12VDC at all times. The pin on the right is grounded by the ECM computer to activate the solenoid. You can test the solenoid by applying 12VDC to it on the bench. It should click.

camgci

I had checked the fuse and voltage to the solenoid valve and had 12v. Could the hose be pinched coming out of the solenoid going up over the tank or do you think it is before going into the valve. During my search, one guy mentioned he got a P0449 and he cleaned out his canister and it went away. The cannister doesn't look very easy to access. Thanks

chillwill

Had the same problem bought the part from the dealer $25 it's located on the passenger side above the rear wheel well unplug and put in new one

FortMorganAl

Yes, the shop manual procedure is to check for wiring issues but http://www.hessh.de/Corvette/FuelTankSystem.pdf recommends The fact that it worked for a few days would indicate an intermittent wiring issue (hard to find - maybe in the connector) or a partially pinched hose that sometimes flows enough and sometimes doesn't. This is where a Tech 2 would come in handy to cycle the valve a lot to see if the new valve is also sticky or it is a plumbing issue.

The canister should have nothing to do with code P0449. An issue there would set code P0446. P0449 says the vent solenoid was commanded to move and the pressure in the tank didn't change as expected. I guess if the canister was totally plugged you might get that code along with a bunch of others but the engine probably wouldn't run right either. But if you want to check, start by removing the right fuel tank. Before I did that I would take the valve back off and cycle it a lot on the bench. Then I would take the gas cap off and try blowing into the hose at the vent. It should be open with the engine off. On the other hand, I've never done that and don't know what a little restriction would mean.

camgci

Thanks, will be working on it this weekend.

camgci

Well, pulled the solenoid valve out I had just replaced(pia on A6) and did a bench check. No clicking so exchanged it and now everythings fine. Haven't tried putting gas in yet but I assume that should be ok too. A lot of work over a defective part. Thanks for all your help.

FortMorganAl

VET4LES

Good news.

weathermaker

So the new part was N/G. Was it an OEM or made in China part? Sucks to have to do a job twice because of someone else fault.

Johnsz51

Guys thanks for the information it was helpful just did it on my 07 but just for additional information I got done cleared codes and light came back on with same PO449. Really had me scratching my head. It's a tight spot and hooking the wire wip that came with it to plug into your car I had a really hard time one handed and bent a prong. Retraced my steps and found this so used dielectric gear to help it slip together after straighten the prong back and problem code is now gone. Be careful when hooking the new wire wip up if needed like in my case.

LowRyter

Mine does the same thing. I changed the gas cap and later the solenoid valve. I can go for a few weeks but it comes back on again.

I took it to Chevy for the nitrogen smoke test. Was more curious about the gas tank leak that I had gotten the letter from Chevy about. Tech found nothing. Switched off the CEL and didn't charge me.

Johnsz51

the bad prong gave me more problems and I had to get a new wiring harness and made sure I got it plugged in carefully. I had tried a gas cap too but did nothing if you have a 449 code it is that solenoid not getting power plain and simple. All good now.

LowRyter

connector or wiring harness?

Johnsz51

The little wiring harness that comes with the evap vent solenoid. So cars need it some don't mine did of course and was the problem after I changed it. Really hard to get connected without being on a lift.

Johnsz51

The little wiring harness that comes with the evap vent solenoid. Some cars need it some don't mine did of course and was the problem after I changed it. Really hard to get connected without being on a lift.

groran

I wonder if it's the battery causing those codes like I read before from other post. How old is the battery?

Johnsz51

Battery was replaced 3 years ago.

LowRyter

The CEL went out when I changed batteries. It came back a few months later. I can shut it off with a scanner but it usually comes on in a few weeks. I feel like the issue is electrical since it comes and go, like a bad connection.

I recently had the dealer run the nitrogen smoke test and they found nothing and turned off the CEL.

LowRyter

could you ID the p/n for the wiring harness? Is it available separate from the part?