p0446 evap code? what is the common cause of this 2009 lacrosse

[jbose211]

check engine light just came on. wondering if anyone else has came across this problem. hopefully it is a simple fix i reset the light but unsure if my car will now auto start was hoping to remote start during the winter now i get this problem right when it starts getting cold out

 

[MelsRegal]

The code points to the vent valve

P0446 Evaporative Emission Control System Incorrect Purge Flow

 

[jbose211]

right but thats a generic code anyone can hook up a scan tool to a car even one thats 5$ and get the same numbers i got. Those numbers could also show up for a bmw which could have different parts all together.

The code isnt specific to gm what i was refering to was what a common failure in these cars could be not what the definition of the code is but thanks for your effort good try i am grateful for that still

 

[oldschool]

The vent valve is a somewhat common failure on GM cars. I had to change mine on the 2007 Allure. There is a solenoid that operates the valve, the valve sticks even though the solenoid is still working. I had mine out, put voltage to it and could hear it clicking but air continued to go thru. Anyway, I hit it with the voltage a couple times in a row and it did start to operate. About three/ four months later it stuck again so I replaced it and was good until I traded the car. Or you could change the gas cap and see if that fixes it.

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[oldschool]

If the check engine light is on the remote start will not work.
You might also have a leak in one of your fuel pipes due to rust if you live in the rust belt.

 

[jbose211]

ya i will have to look for that so far the light is out

 

[G-195039]

check engine light just came on. wondering if anyone else has came across this problem. hopefully it is a simple fix i reset the light but unsure if my car will now auto start was hoping to remote start during the winter now i get this problem right when it starts getting cold out

I have a 2008 with the same problem. I changed the gas cap and it turned off for a while but kept writing " check gas cap". It came back now that I have to go and get my tires changed for winter. I'm going to change the vent valve I guess even though I have no clue how.

 

[jbose211]

my did not say gas cap just a generic code displayed i reset the light and have not had a problem since but ill be looking around when its warm

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[jbose211]

I replaced the purge vent valve under the hood and the light came back on a few days later? so does that mean the valve near the tank in the rear is bad if so how hard is it to get at and replace

 

[2007LucerneCXL]

The P0446 code will only tell you something is wrong in the EVAP system not what part is having the error. The vehicle will take a reading when the tank is between 1/4 to 3/4 full so after a reset it's may require so many starts / miles to come back up.

Here's some diagrams on the system and the code can be any of those parts of the EVAP system. A smoke test, professional scan or shop visits might be required if you unable to find it.

 

[jbose211]

Yeah I've seen that diagram online before sounds like a page right out of a website online I appreciate the information unfortunately it's the same information that everybodys seen online already it doesn't really point them in the right direction that information is just as generic as the code. Seen that information on repair pal and and another.

I don't think it does any good to share the same information that other websites are sharing that doesn't lead to a solution.

I was hoping that somebody else had this problem before and they were aware of what was common.

That diagram isn't even the one that shows the EVAP system it shows the whole fuel system the site that refers to the smoke test and all that stuff clearly shows EVAP system diagram but good try I highly doubt removing a fuel line or tank strap is going to make a light come on at least not an EVAP code looks like I'm still at square one again

 

[2007LucerneCXL]

There is no one answer to the EVAP code without troubleshooting the problem. You don't have a clue on what the EVAP system is as it is all in the drawings it starts from the fuel inlet, to the fuel tank, to the canister, to the line, to the engine that's all parts that can toss a EVAP code.

But hey start with a new gas cap, people like that one a lot, and see if that cures it otherwise I hope you get the problem resolved.

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[jbose211]

thanks for the efforts i figured out what to do now.

i am going to replace the vent valve in the rear of the car.

To anyone who comes across a similar issue more then likely the valve in the rear of the car or the wiring goes bad causing check engine light to illuminate.

if by some chance the gas cap is causing an issue that would throw a different p code.

p0446 relates to the valve you could waste time inspecting the hose or try messing with the wiring however you can just order a new valve complete with the wiring and hose assembly for 25$ free shipping and be done with this.

If you have a leak in the filler neck it might throw this code but is unlikely you would notice a different code.

If anyone goes in there to inspect hoses or wiring and thinks they see a problem your more then likely going to wish you had just replaced it all in one shot the assembly is cheap enough.

i will provide an image which should show the general area to inspect.


also make note of excessive fumes if you smell raw gas alot that could be a sign the valve isnt working properly.

also when you open your gas cap do you notice any pressure come out do you hear anything if you do not then there is a good chance something is leaking or not working but more then likely not the gas cap on the 2009 that would display a different p code i do not know about older models series 2 for the 2009 p0445 would show up if the gas cap was the issue but you can replace if you would like maybe someone wants a locking cap idk.

On a high mileage gm product even if the plug or the hose is bad the evap valve will more then likely fail so dont waste effort get in there and and replace everything.

At almost 10$ shipping for most parts it does not make sense to replace a hose then try a plug then do the valve then get a cap ect you will pay alot of shipping.

I hope this extra info helps someone.

Ps you might need to download the image and blow it up.


Also i should mention that if you can find a garage that has a fancy scan tool you can activate the valve open close it you can test multiple functions without smoke that would be the easy way

 

[oldschool]

So my response on Nov. 6th didn't help. I think all the correct info was there, all you had to do is go to youtube and find a video on how to change the valve on a GM product since most of them have the vent valve in the same location. By the way the valve is up in the fender next to the rear left wheel. Two bolts if I remember right, one electrical connector and the hose. Doesn't even have a clamp as far as I know, just slides onto the steel tube.

 

[jbose211]

So my response on Nov. 6th didn't help. I think all the correct info was there, all you had to do is go to youtube and find a video on how to change the valve on a GM product since most of them have the vent valve in the same location. By the way the valve is up in the fender next to the rear left wheel. Two bolts if I remember right, one electrical connector and the hose. Doesn't even have a clamp as far as I know, just slides onto the steel tube.

 

[jbose211]

Yeah thanks for your help man I wasn't exactly sure where it was I do know how it works and what could possibly trigger it and stuff like that I've learned a bunch of that stuff I just never really looked for it specifically couple people had told me that you have to drop the gas tank to get at it and stuff and that it was underneath the gas tank which seemed like a pain in the buttglad to know that it won't be that difficult to get off and replace it seems like most of the things on this car are easy to get at and work on compared to some cars.

I still do not know if any fuel pipes are leaking or not I mean that could be a possibility as I'm getting poor mileage the only thing that I know of is that I've been told that if you had a fuel line leaking that would be a different code. I am not really sure however everything looks solid underneath the car it is possible that where the lines run up the side of the car in the rear that there could be something going on there but I don't really know I would have to take a look at it.

So far I did what one guy said in a video he said he replaced a bunch of parts and he ended up having a valve on the hood which was no good which was the main cause I didn't do much else because I didn't want to waste a bunch of extra money in time throwing random parts at the car so I just did one of the easier things and we placed a valve on the front of the car and now I'm going to try replacing the valve on the back of the car comes with a wire and a new hose.

you got me thinking that maybe there is a vent line under there old rubber or something if you could explain what is the location of the lines that I should be inspecting to see if they're leaking I'm sure there are several on the vehicle. it looks like they are on top of the tank

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[jbose211]

The P0446 code will only tell you something is wrong in the EVAP system not what part is having the error. The vehicle will take a reading when the tank is between 1/4 to 3/4 full so after a reset it's may require so many starts / miles to come back up.

Here's some diagrams on the system and the code can be any of those parts of the EVAP system. A smoke test, professional scan or shop visits might be required if you unable to find it.
View attachment 28080 View attachment 28081

Ya thanks for the info your pictures do help i can now find those vent lines and inspect

 

[2007LucerneCXL]

Unfortunately if you read enough posts on the subject every part of the EVAP system is the correct solution but it only applies to that owners vehicle. From grease on the cap to filler neck to blowing air through the purge valve with everything else in between has been a repair so the most common part is the one that fixes your vehicle.

 

[oldschool]

Can't really help you with the location of the lines, I don't have the car anymore and I changed that valve about three years ago.
The hose going into the valve is about 0.5 inch. Perhaps you could disconnect it, slide a piece of garden hose on to the steel line and blow into it using your mouth, not high pressure. I would think from there it's a sealed system, so you shouldn't be able to blow air into the tank.
Another thing you mentioned, I had a rusty fuel line leaking on the left side just ahead of the left rear wheel last winter. Started to see a stain on the driveway, but before that the car would crank a couple seconds before starting when I had been sitting for a while. What was happening is the pressure that would normally be in the line going to the injectors was bled off due to the leak, so if your car cranks a bit longer than it should on the first start of the day you could have a leaking line. That was the last straw, I had so many problems with that car it was time to let it go.

 

[2007LucerneCXL]

Post #10 is the EVAP and fuel lines for the 2009 Lacrosse as FYI.