CEL P0449 --RESOLVED-- - Chevy Colorado & GMC Canyon

ColoradoFans.com is the premier Colorado Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 10-24-2007, 07:40 PM   #1 (permalink)
Senior Member
 
Join Date: Nov 2005
Location: Central NJ
Posts: 522
Default CEL P0449 --RESOLVED--

So I currently have a CEL and the code is P0449, Evaporative Emission Control System Vent Valve/Solenoid Circuit.

Some background, while I was en route to WI 2 weeks ago my gas cap went bad. I bought one at an auto zone along the way for $12. All seemed well until last week when I got a CEL. I checked the gas cap and it was loose so I tightened it and the light reset itself shortly thereafter. I got another CEL yesterday on the way to work so I checked the gas cap and it was tight. I had Supermodulation clear the light and pull the code with his scanguage. P0449. Today the light is on again and the gas cap is still tight.

So, where is the vent valve? I want to take a quick peek before I take a trip to the dealer on this one (I am still under factory warranty). If it is something simple I will take care of it myself. Also, could the gas cap be the culprit here? If it is then why isn't the code a P0457 for a loose/missing gas cap? Anyway, thanks for the help!
__________________
05 SB Orange 4x4 Z71 LS I5 atx 3.73 CC
LIFTED CLUB MEMBER #67
2008 TOTW #9
tjm276 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 10-24-2007, 07:47 PM   #2 (permalink)
Senior Member
 
Join Date: Dec 2003
Location: orange,ct
Posts: 421
Default

http://service.gm.com/gmspo/mode6/pdf/2 ... file5a.pdf
orangez71 is offline   Reply With Quote Quick reply to this message
Old 10-24-2007, 09:47 PM   #3 (permalink)
Senior Member
 
Join Date: Nov 2005
Location: Central NJ
Posts: 522
Default

So the "electrical integrity" of my fuel tank vent circuit is at fault. So what does that mean? Could it be as simple as a harness came unplugged or is corroded? Where do I go about looking for this vent/solenoid?
__________________
05 SB Orange 4x4 Z71 LS I5 atx 3.73 CC
LIFTED CLUB MEMBER #67
2008 TOTW #9
tjm276 is offline   Reply With Quote Quick reply to this message
Old 10-25-2007, 01:25 AM   #4 (permalink)
Senior Member
 
Join Date: Apr 2007
Location: Columbia Missouri
Posts: 833
Default

Still have warranty, take it to the dealer.
__________________
2006 Canyon crew cab true red
I-5 Z-71 4wd auto
factory side tubes,splash guards and tailgate cap. after market brush guard, Hellwig 550's
2003 Tracker Pro-Guide Deep V-16
40 hp4st. Mercury.
2009 KLX250s Sunbeam Red
http://s207.photobucket.com/albums/bb205/randylo/
Randy is offline   Reply With Quote Quick reply to this message
Old 10-25-2007, 03:56 AM   #5 (permalink)
Senior Member
 
Join Date: Feb 2005
Location: Oakland Bitch!
Posts: 9,866
Send a message via AIM to turbizzy
Default

Quote:
Originally Posted by Randy
Still have warranty, take it to the dealer.
Yea do ya?

Vent Control Valve is the valve that closes amostpheric air from entering the normally open vented charcoal canister for a brief time while the PCM checks the evap pressure sensor to ensure proper vapor pressure exists in the evaporative emissions system. If the vent control valve is sticking mechanically or has an open or short electrically it will tell the PCM and will set a CEL.

However if you take it to the dealer most likely they will notice an aftermarket fuel cap and could deny you warranty work if they find the cause of the CEL is due to an evap leak. However that code is for an electrical issue in the vent control valve itself so technically it doesn't care if the evap system is leaking it just wants the vent valve replaced.

Usually vent valves are bolted to the charcoal canister.
__________________
Izzy 2005 Black CrewCab SS wannabe
turbizzy is offline   Reply With Quote Quick reply to this message
Old 10-25-2007, 08:11 AM   #6 (permalink)
Senior Member
 
Join Date: Nov 2005
Location: Central NJ
Posts: 522
Default

Quote:
Originally Posted by turbizzy
Quote:
Originally Posted by Randy
Still have warranty, take it to the dealer.
Yea do ya?

Vent Control Valve is the valve that closes amostpheric air from entering the normally open vented charcoal canister for a brief time while the PCM checks the evap pressure sensor to ensure proper vapor pressure exists in the evaporative emissions system. If the vent control valve is sticking mechanically or has an open or short electrically it will tell the PCM and will set a CEL.

However if you take it to the dealer most likely they will notice an aftermarket fuel cap and could deny you warranty work if they find the cause of the CEL is due to an evap leak. However that code is for an electrical issue in the vent control valve itself so technically it doesn't care if the evap system is leaking it just wants the vent valve replaced.

Usually vent valves are bolted to the charcoal canister.
To the dealer I go then. I still have my original fuel cap so I can throw that back on and have the dealer replace that under warranty, too.
__________________
05 SB Orange 4x4 Z71 LS I5 atx 3.73 CC
LIFTED CLUB MEMBER #67
2008 TOTW #9
tjm276 is offline   Reply With Quote Quick reply to this message
Old 10-27-2007, 08:51 AM   #7 (permalink)
Senior Member
 
Join Date: Nov 2005
Location: Central NJ
Posts: 522
Default

SO I made an appointment to go to the dealer on Monday so, of course, the CEL cleared itself. WTF!?!?! I will still go to the dealer to have them check everything out/replace the fuel cap.

Anyone have an idea on why the CEL comes on randomly and then turns off after a day or so of use? This is wierd. I am starting to wonder if there is a loose wire or a loose connector plug on a harness somewhere.
__________________
05 SB Orange 4x4 Z71 LS I5 atx 3.73 CC
LIFTED CLUB MEMBER #67
2008 TOTW #9
tjm276 is offline   Reply With Quote Quick reply to this message
Old 10-28-2007, 01:57 AM   #8 (permalink)
Senior Member
 
Join Date: Apr 2007
Location: Columbia Missouri
Posts: 833
Default

After the dealer visit it should go away. These systems are picky. I always give my cap extra spins to make sure after reading issues on here.
Keep us posted.
__________________
2006 Canyon crew cab true red
I-5 Z-71 4wd auto
factory side tubes,splash guards and tailgate cap. after market brush guard, Hellwig 550's
2003 Tracker Pro-Guide Deep V-16
40 hp4st. Mercury.
2009 KLX250s Sunbeam Red
http://s207.photobucket.com/albums/bb205/randylo/
Randy is offline   Reply With Quote Quick reply to this message
Old 10-30-2007, 10:10 AM   #9 (permalink)
Senior Member
 
Join Date: Nov 2005
Location: Central NJ
Posts: 522
Default

UPDATE:

I dropped the truck at the dealer yesterday morning and they called me yesterday to inform me of the problem. The gas cap is bad, as I suspected, and the vent valve solonoid is bad. It is kind of strange to have 2 failures on the same system of the truck at the same time but I am not complaining. One trip to the dealer is better than 2. Anyway, they didn't have the vent valve soloniod in stock so I had to leave the truck overnight. It should be all fixed up today.

The technition told me that it is not uncommon for the CEL to come on and then turn itself off after a bit of driving and then come on again later. I guess it is how the PCM works.
__________________
05 SB Orange 4x4 Z71 LS I5 atx 3.73 CC
LIFTED CLUB MEMBER #67
2008 TOTW #9
tjm276 is offline   Reply With Quote Quick reply to this message
Old 10-30-2007, 07:15 PM   #10 (permalink)
Senior Member
 
Join Date: Nov 2005
Location: Central NJ
Posts: 522
Default

The issue is resolved. The vent valve solenoid was stuck open. The wiring was intact so the vent valve solenoid was replaced. The service adviser told me the vent valve problem could have actually caused the gas cap failure. I don't understand that but I guess I'll take his word for it. Anyway, here is the summary from my paperwork:

Quote:
Job# 1 Charges--------------------------------------------------------------------

Labor---------------------------------------------------------------------------

J# 1 18CVZZ Engine Emissions Hours 0.5 Tech(s): 58 WARRANTY
Customer states: "Check Engine Light" was on/pulled code for P0449 (Evap Emission Control)/Check and report code P0449 Evap Vent System failure/Pressurize Evap system. Gas cap leaking (Refer to Job #3) System would not hold pressure/replaced cap. (Job#3)/Pressure Evap System/Check for leaks/Vent solenoid stuck open/Replaced vent solenoid/Wiring OK/Checked Vehicle/Operating as designed/Concern Corrected.

Parts-------Qty-------FP-Number-------Description-------List Price-Unit Price-
1 10386359 Hose 3.120 WARRANTY
Total - Parts 0.00
Job# 1 Totals-----------------------------------------------------------------
Job# 1 Journal Prefix CVCS Job# 1 Total 0.00


Job# 2 Charges--------------------------------------------------------------------

Labor---------------------------------------------------------------------------
J# 2 01CVZZINSP Multi-Point Inspection Hours: 0.00 Tech(s) 58 0.00
Perform Multi-point Inspection

Job# 2 Totals------------------------------------------------------------------
Job# 2 Joiurnal Prefix CVCS Job# 2 Total 0.00


Job# 3 Charges--------------------------------------------------------------------

Labor---------------------------------------------------------------------------
J# 3+17CVZ Engine Fuel Hours: 0.40 Tech(s): 58 WARRANTY
Add-on line: Replaced Gas Cap
(From Job #1) Gas cap replaced due to internal failure/Would not properly seal/Resulting in Evap leak/Replaced gas cap/Checked over vehicle/No Check Engine Light/Operating as designed

Parts-------Qty-------FP-Number-------Description-------List Price-Unit Price-
1 15794103 Cap 3.028 WARRANTY
Total - Parts 0.00

Job# 3 Totals------------------------------------------------------------------
Job# 3 Journal Prefix CVCS Job# 3 Total 0.00
__________________
05 SB Orange 4x4 Z71 LS I5 atx 3.73 CC
LIFTED CLUB MEMBER #67
2008 TOTW #9
tjm276 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy Colorado & GMC Canyon forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 05:27 PM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0