Need help with error code P0446

[Sanny651]

I got this error code today on my 2003 Silverado. Gas cap was on tight. Read that it could be one of the following:
EVAP canister purge outlet tube (EVAP canister purge valve to EVAP canister) blockages or kinks.
EVAP canister tube (fuel tank to EVAP canister) blockages or kinks.
Fuel vapor elbow on EVAP canister contaminated.
Restricted EVAP canister.
Canister vent (CV) solenoid stuck closed (partially or fully).
Plugged or contaminated CV solenoid filter.
EVAP canister purge valve stuck open.
Fuel filler cap stuck closed (no vacuum relief).
VREF circuit open in fuel tank pressure (FTP) sensor.
Damaged FTP sensor.

Where is this cannister they reference? I cleared the code with my reader, but would like to inspect the problem further. Not sure if it's related or not, but my 4WD switch wouldn't work this afternoon either and the dash read "Service 4WD". Got home, turned it off, got the reader and the 4WD switch now works again??

Any help would be greatly appreciated!

[catman4x4m]

i hate to say this but there is only one solution to fix this
(BUY A FORD)

[Sanny651]

Thanks, but I'd rather walk.

[ArcticDad]

<div class='quotetop'>QUOTE (Sanny651 @ Sep 24 2006, 06:04 PM) <{POST_SNAPBACK}></div>

 Quote:

I got this error code today on my 2003 Silverado. Gas cap was on tight. Read that it could be one of the following:
EVAP canister purge outlet tube (EVAP canister purge valve to EVAP canister) blockages or kinks.
EVAP canister tube (fuel tank to EVAP canister) blockages or kinks.
Fuel vapor elbow on EVAP canister contaminated.
Restricted EVAP canister.
Canister vent (CV) solenoid stuck closed (partially or fully).
Plugged or contaminated CV solenoid filter.
EVAP canister purge valve stuck open.
Fuel filler cap stuck closed (no vacuum relief).
VREF circuit open in fuel tank pressure (FTP) sensor.
Damaged FTP sensor.

Where is this cannister they reference? I cleared the code with my reader, but would like to inspect the problem further. Not sure if it's related or not, but my 4WD switch wouldn't work this afternoon either and the dash read "Service 4WD". Got home, turned it off, got the reader and the 4WD switch now works again??

Any help would be greatly appreciated! [/b]

GM trucks have a BIG problem with that Todd. My brother has had his replaced 3 times in 50k miles, and my dad just did his the first time after 14k - they build up with dirt and plug. Real bad if you live in the country.

It's a $500+ fix at the dealer.

Jay


PS - I realize that my post is of little help. My brothers & dads have been covered under warranty, but as common as I know this is, I think you'd be wise to find out if there was a service bulletin issued on this. I would bet there is.

Jay

[catchatter]

The most common thing I've seen set code P0446 on your truck has been the evap vent solenoid. They just quit working and are stuck open. If your scan tool has a special function feature that allows you to command it on and off, listen for it to make a click sound when turning it on and off.That's the easiest way to test it. I think it's a pain to get at! I believe its on left frame rail at the very front of box. Otherwise its at the rear of the gas tank. If you can get some jumper wires on it connected to a pwr/gnd you could test it that way also.

As far as the service 4wd light can you scan the codes?Can't remember the code number but I've seen a lot of the 4wd switches be the cause. I think there is a service bulletin out for that year truck in regards to the 4wd switch if it has a certain code set. I can check further if needed just let me know.

hope that helps some.

[ArcticDad]

<div class='quotetop'>QUOTE (catchatter @ Sep 24 2006, 09:02 PM) <{POST_SNAPBACK}></div>

 Quote:

The most common thing I've seen set code P0446 on your truck has been the evap vent solenoid. They just quit working and are stuck open. If your scan tool has a special function feature that allows you to command it on and off, listen for it to make a click sound when turning it on and off.That's the easiest way to test it. I think it's a pain to get at! I believe its on left frame rail at the very front of box. Otherwise its at the rear of the gas tank. If you can get some jumper wires on it connected to a pwr/gnd you could test it that way also.

As far as the service 4wd light can you scan the codes?Can't remember the code number but I've seen a lot of the 4wd switches be the cause. I think there is a service bulletin out for that year truck in regards to the 4wd switch if it has a certain code set. I can check further if needed just let me know.

hope that helps some.[/b]

I just had this happen to my F150 - 45k miles. In turn the evap canister was filled with gas, so they couldn't blow it out. I've heard before that if you over-fill your gas tank, as I always do, that these things plug with gas. I guess I'll stop doing that now...

Jay

[07Arcticcat650h1]

I have a 04 4X4 Silverado and that code came up on me when I had about 45000

miles. It was that evap canister and was about 500 dollars to fix at the dealer. I

drove it for about 70000 miles before I got it fixed. Don't think it did any damage

all gauges had proper readings the whole time. I did get it fixed once I hit 115,000

miles because it any other codes where to start coming on I wouldn't know it..

My .02[size=3]

[Sanny651]

Thanks for the info guys. I do have a code reader and that's the only code that came up. I cleared it out and it hasn't come back since.

What does that evap vent solenoid do, and what harm does it cause if left "as is" for a while?

[ArcticDad]

<div class='quotetop'>QUOTE (Sanny651 @ Sep 25 2006, 02:03 PM) <{POST_SNAPBACK}></div>

 Quote:

Thanks for the info guys. I do have a code reader and that's the only code that came up. I cleared it out and it hasn't come back since.

What does that evap vent solenoid do, and what harm does it cause if left "as is" for a while?[/b]

From what I understand Todd is that keeps the gas smell out of your garage - I could be way off. If the thing is plugged, I suppose it could cause a vacuum problem in the fuel system???

Jay

[kevinbender0311]

filters and reburns the gasses not gas from your fuel tank. if you cleared it and it doen't come on for a few hundred mile might have been just a fluke. emissions junk imo.