[Slartibartfast]

I recently needed to fix the common P0449 EVAP valve solenoid problem on my 2006 Colorado W/T. I found bits and pieces of the repair all over the internet (including 355nation) but none of them were complete diagnosis and repair instructions, and many of them showed the solenoid and canister already on the bench without showing how to locate and remove them. Most of them also didn't tell you how to be sure the solenoid was truly defective before you go out and buy a component you won't be able to return if it turns out the wiring or computer are actually at fault.

Eventually I pieced together information from multiple sites and added my own expertise and decided to make a comprehensive diagnosis and repair video for this common Colorado/Canyon problem. This video shows you how to do a repair for about $70 (including taxes) in parts and about an hour of your time that would cost $400-500 if you pay your dealership to do it for you. I've even seen the two parts required for under $40 combined (before tax) from online parts stores, but I bought mine from the dealership.

This video is almost 27 minutes long but it covers EVERYTHING from start to finish, and even gearheads of average skill level should be able to complete the repair in about an hour.

So here you go... my very first YouTube instructional video ever. Hope it helps somebody.

_0qkzTxWCzA

https://www.youtube.com/watch?v=_0qkzTxWCzA

 

[rshadd]

Very informative and nicely done.

 

[BlackZQ8]

Wish I had the video when I did mine, thanks for sharing!

 

[Slartibartfast]

Wish I had the video when I did mine, thanks for sharing!

So do I. LOL

You're welcome.

 

[Rick_crew]

That problem is so common?
Hmmm. May be an item to add to the preventive maintenance list.

Thanks for taking time to post the vid!

 

[Slartibartfast]

That problem is so common?

According to the Internet... yes.

 

[rshadd]

A quick site search for p0449 found over 49 threads on the topic. So, yeah it's a pretty common problem.

 

[cart7881]

Very detailed video. If a person has the oval plug on their truck they can eliminate the need for the jumper harness by using Vent Solenoid Valve part number 25932571 (214-2149). As mentioned in the video, at some point GM changed the harnesses in our trucks to the square connector. I know the 2011 has the square connector.

 

[agaddis355]

Very detailed, and now I'm going to have to fix my p0449, no more excuses.

 

[Rick_crew]

Both the solenoid and the adapter are available at Amazon..


Solenoid, GM part #20941985, $15.28


Wiring adaptor #19257603 $17.31


.
Thanks again Slartibartfast!

 

[cart7881]

Very detailed, and now I'm going to have to fix my p0449, no more excuses.

I have one of the Vent Solenoid Valves that I mentioned in Post #8. I am certain that it will work as I tested it in my truck. It will not require a separate jumper harness. I will send it to you, free of charge, if you will just post here whether or not it worked for you. It is in new condition, I just used it to test the circuits in my truck. It will not directly connect to my truck as I have a square connector. If you are interested, PM me an address.

 

[shayapaula]

awesome, thank you sir

 

[atxjax]

I am having P0442 small evap leak. Im wondering if i can take out the whole unit just like in the video and cap off the two vapor ports...........then inject smoke on the solenoid side to see if its leaking somewhere.

 

[cart7881]

Depending on which direction that you inject the smoke, you can either test the canister or the solenoid valve. If you are going to disconnect the hose to the solenoid valve, it would be best to disconnect it at the canister, rather than at the valve. At the canister connection, there is a clip that has to be removed to release the connector.

 

[atxjax]

Depending on which direction that you inject the smoke, you can either test the canister or the solenoid valve. If you are going to disconnect the hose to the solenoid valve, it would be best to disconnect it at the canister, rather than at the valve. At the canister connection, there is a clip that has to be removed to release the connector.

The solenoid is normally open correct? Do I need to apply 12V to it to close it for testing?

 

[cart7881]

Yes & Yes.

 

[Tyro]

Thanks for the informative post! I have the P0449 code and will use this video to fix it in the near future! :thumbup:

 

[atxjax]

Yes & Yes.

Thanks. Since it's a solenoid it doesnt matter which pins are ground and +12V correct?

 

[1BADI5]

I just watched the video............. Well Done, complete and concise

Might need to Sticky this one for sure

 

[atxjax]

I want to add in this thread that some quick checks can be done on the valve while still on the truck.

This applies to 04-06 as I do not know the color of the wires for later models.

So you should have 12V at the Orange wire even with truck off. Now with the truck off you should see the same 12V also at the white wire because the PCM is not commanding a ground to that point with the truck off. If you don't get 12V with truck off at the white or see something in the milivolt range then the solenoid itself is bad and the coil has opened..

If you have 12V at the orange wire and at the white wire the solenoid is OK, you should be able to apply a ground to the white wire and hear the valve open and close by removing and applying the ground wire repeatedly. If you remove the valve and blow air through the line attached to it, the air should come out the top round cap side. If you apply 12V to it and blow again there should be no air coming out. if air is coming out it is bad.

( CAUTION........DO NOT LET THE GROUND YOU ARE APPLYING TO THE WHITE WIRE COME IN CONTACT WITH ORANGE WIRE....IT WILL BLOW THE FUSE AND WHO KNOWS WHAT ELSE WILL HAPPEN WITH THESE PICKY PCM's )

If all is OK then what you can do is remove entire unit ( canister along with the valve ) apply 12V to the orange pin and ground to the white pin to close the valve. Cap off one ports at the canister of then pressurize the canister with very low pressure ( 5PSI or so ) and use a spray bottle with liquid detergent to look for any bubbling leaks once sprayed. or if you have a smoke tester use that.