Hey guys. Getting the Check Engine light on with a P0446; Evaporative Emission System Vent Control Circuit code that I can't clear for more than about 10 minutes. 05 Limited Roadster.

Any suggestions? Found a thread from a couple of years ago noting something about a solenoid. Any ideas what part # this would be and more advice about replacing it?

Cheers!

 

I think the part you are talking about is on the driver side inner fender, it is the part with the rubber flange that just sits on a bracket.
Chrysler part #05098143AB
Mercedes part #000 470 35 93
eBay part

 

Dave, I think that may be wrong. You linked to the PURGE valve, which does sit where you say it does. But P0446 implies (to me anyway, could be wrong) the VENT VALVE. That is, the shutoff/vent valve on the Charcoal Caninster. See the snips from the Student Guide below.

And Im not so much correcting you as ASKING you - I've been trying to help Andy (Aking57) with his P0446 code, they changed the vavle you point out, CEL came back next trip.

 

I've been doing my homework and not getting as far as I'd like. What do YOU think?

I THINK I understand the system's operation, but the definition of a P0446 in our DTC list seems to disagree with the definition in other vehicle and other Mercedes.....

 

Thanks for advice. Still not sure what I can do here, though. From research I did, believed it was the vent valve too, and thought this was the part:

http://www.ebay.com/itm/291533008513?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Been clearing the code, it keeps coming back. What I find most odd about this is that it kicked in after a massive rainstorm -- no garage, so car is outside under a cover -- and I've always had weird issues with heavy rains doing something to the electrical, triggering false codes, causing the spoiler to rise up on its own, etc. So kind of operating under the partial assumption that this P0446 is BS, although whenever this happened before the code either vanished on its own or I'd clear it with my code reader and it would stay gone.

Anyhow, annoying. That Check Engine light makes it impossible for me to enjoy driving the damn car, kicks in the old OCD even though I'm 99% sure this is pretty much meaningless. I wish you could just hide codes for good. This seems more like a nuisance code than anything else.

 

A bad fuel cap can cause that code. I would try a new cap first before you start spending money on parts you may not need.

 

Its an emissions code, so if the car is running fine and you do NOT need to pass emissions, well, screw it.

 

This could be quite the bear to lock down. I know OCD, believe me it is a pain in the A$$ to delve into a minor quirk. Having OCD makes this a 'what-if' nagging burning, annoyance right? All the things it could be magically balloons into something major somewhere down the road (in our minds). So, if you just cannot get over that dang code (burning into your mind) then I would suggest casually (over time) looking into the systems associated with setting that code. Some of the possibilities (even something simple as the loose gas cap or some vent line in the evap system cut/damaged), loose wire, water intrusion, rodent damage. All WILL make it worse down the road (which is why us OCD folks tend to not let it go by the wayside and exhaust options beforehand). Think of it as a long term project, or get over the nagging code issue. Good luck, if you tackle this one, you may definitely need it!

 

Drove my old '89 Probe down to my sister's ( about 100 miles ) last Friday.
About halfway there, the announcement "Coolant Low" popped up, so I ignored it.
BIG MISTAKE.
When I was but 5 miles from her place, the CEL came on and the temp display pegged at the top.
I found a handy station and poured water in using a paper cup I found in the trash, finally got her cooled down,
but noticed while I was pouring the water in that the 90 degree plastic neck of the radiator cap ( this is a Mazda, after all ) had been chewed by one of the squirrels that Squirrel Crusher had inadvertently missed.
Long story short, got to my sisters and used her car to go find some JB-Weld.
Now good as new, checked it when I got back home, NO coolant loss.

 

Problem is I'm in Ontario, with the ridiculous Drive Clean regs. So I need to be emissions tested every two years, and have no clue if the car would pass. Plus, driving with the CEL on always bothers me because I'm afraid that I'll eventually miss a real problem. Had that happen with a car about 20 years ago and wound up with a $2,500 bill. So, paranoid.

Anyhow, problem was solved today. Needed an oil change so booked car in with my regular guy. Asked him to take a look at the P0446. He did and found no power was going to the evap system. Parts fine. Started tracking down the problem. After five plus hours, he found where a mouse or something had chewed through a wire. Fixed wire, CEL went away, power going back to system. Nice $400 bill for that expedition, though...

But at least the problem has been solved. Thanks all for advice!

 

I am glad you found the problem, you actually got it fixed quite cheaply.
Here in Ontario they will not start to do the check if the CEL is lit, it is an automatic fail.

 

Glad you got it nailed down! Many who have/had rodent damage are still feeling the results of those damn 4 legged creatures!