P0449

jonesj28405 · May 1, 2009

I have a 2005 Sierra Denali with a P0449 OBDII code what does this mean and what is the likely culprit. The truck has less than 36000 miles.

pennzoil29 · May 1, 2009

Welcome aboard Go to GM-Trucks home page, and there is a trouble code look up at the top.

Draenor · May 1, 2009

DTC P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit

Check your wiring first. Then see if the solenoid need to be replaced. It is possible it is stuck closed.

don0442 · May 2, 2009

This code is almost always the evap solenoid, but in some cases, it can be the gas cap (Must use GM gas cap, NOT aftermarket. I know, I made this mistake.) It can also be a generic vacuum leak. The solenoid is a very common failure, go to your gm dealer, they have an updated assembly, or if you are very brave, take yours apart and clean it. If that doesn't fix it, you will need to have someone with a smoke machine diagnose this issue.

bigredmariner · May 4, 2009

Use the search function and search the code on here, several members have had this issue, myself included. If you are a do-it-yourselfer, you will be able to sift through the info and fix the prob. Most likely bad solenoid, and they are pretty cheap from GM parts direct, $60 or so. Not very difficult to do. Good luck and welcome aboard.

jonesj28405 · May 4, 2009

This code is almost always the evap solenoid, but in some cases, it can be the gas cap (Must use GM gas cap, NOT aftermarket. I know, I made this mistake.) It can also be a generic vacuum leak. The solenoid is a very common failure, go to your gm dealer, they have an updated assembly, or if you are very brave, take yours apart and clean it. If that doesn't fix it, you will need to have someone with a smoke machine diagnose this issue.

I bought a new GM cap just to rule out the easy fix and had a buddy scan and then clear the code. I replaced the cap and drove about a mile and the light came on again. I will investigate the solenoid. Thanks to all for your help.

HOUSTON_MADRIGAL · July 9, 2009

Check on "Check Engine Light Code P0449" topic, you will find a lot of useful information.

cowboysgeetar · March 1, 2011

Check on "Check Engine Light Code P0449" topic, you will find a lot of useful information.

36000? Shouldnt warranty cover this for free esp if its happening on all GMCs?

zalez · March 1, 2011

It's a 2005, so it would be out of the 3 yr warranty

36000? Shouldnt warranty cover this for free esp if its happening on all GMCs?

Digger02 · March 5, 2011

Hey - have a 2003 5.3V8 silverado, 145,000 miles - the CEL came on about a month ago - code reader said PO449 - I was just going to replace the solenoid, and ordered it, but it was two snowy and cold to work on my truck in the driveway. When the snow melted, I crawled under the truck, and found my solenoid and filter was on top of the frame rail in front and above the gastank - it was virtually unreachable for a fat-armed guy like myself. I was reading on various web groups about how GM garages will charge a few hundred to do this, and relocate the solenoid in the process - on one of them, I saw a guy suggest to run a can or two of SEAFOAM through the gas tank. For grins, I tried the SEAFOAM this week, and after about 15 gallons of gas consumed, the code cleared itself. I'm shocked to say the least - I let you know how it goes.

If some people here have figured out the trick to getting the solenoid valve and cannister disconnected from the above-the-frame location between the cab and bed, let me know - I just can't believe there isn't a trick to changing this out.

Dave