The previous answer was good for high dust environments (and if you have a Ford Van all environments are to be treated as high dust) but for those of us in high corrosion environments, consider the following:
If you have an Explorer (Or Ranger/Mazda B-series) check for a broken wire near the left side framerail near the rear axle.
If you have a Hyundai (including Kia), Nissan (including Infinity) or Toyota (including Lexus or Scion) you should disconnect the electrical connector and then apply and remove 12V power to the vent solenoid/valve. The difference between 12V applied and not applied should be the difference between not being able to blow through it and being able to. After testing at least 5 times, if it fails even once, replace the solenoid/valve.
In the case of Nissan or Toyota, if replacing solenoid/valve it is usually best to replace the canister as well as you might inadvertently break the canister while replacing the solenoid/valve. With many Nissan vehicles, it is almost impossible to not break the canister without using techniques involving unreasonably high fire hazard.
Hey Brian==It is probably the gas cap not on tight. Have the codes removed and see if it comes back on after you tighten the cap.GoodluckJoe
Well, my experience with a 2000 GMC 3/4 ton truck says otherwise.
A loose gas cap will not give you P0446 because that is the code for a failed vent test.
Here's how it works: To check the vent system the engine vacuum valve is opened at the same time as the charcoal filter vent valve is closed. This creates a vacuum in the gas tank and when the vacuum reaches a certain level, the vacuum valve closes and the vent valve opens and a timer is started. If there is a restriction in the vent valve or it doesn't operate electrically, the tank fails to re-pressurize within the correct time and you get a P0446.
Here's what I did: I removed the vent valve and found it choked with a fine dust. I cleaned the valve, but noticed that there was lots of dust in the tube running down to the charcoal cannister and realized the gravel filter in the vent valve is useless at stopping dust. I took out the cannister and discovered an amazingamount of dust clogging it up. I cleaned the cannister by holding it vent side down and sharply tapping it many, many times it while blowing air (at low pressure) through it toward the vent side until it passed air freely both ways. Did I mention that there was an amazing amount of dust that came out of the cannister? I would think that gasoline residues from overfilling might clog up the cannister too, but that didn't happen in my case.
Below are what I consider the possible causes of P0446 in the order of least likelihood (IMO) for a vehicle used in a high dust environment:
Electrical vent driver circuit in computer burned out (especially if the vent valve is shorted), electrical vacuum valve driver circuit burnt out, vent valve coil open or shorted, vacuum valve coil open or shorted, bad vacuum sensor in the gas tank, vent valve filter clogged with dust, charcoal cannister clogged with dust or residues.
Removing and replacing the vent valve and especially the charcoal cannister in a GMC truck is a major, major pain in the a-- because the entire vehicle was carefully engineered by GMC so as to make replacement as difficult as possible. It does no good cleaning and replacing a clogged vent valve as the cannister will be clogged too. A new cannister is about $175, but a cleaned one is free.
BTW, my vent test works perfectly now. Added by Protoart: If you have the P0446 code and the vent valve is bad, don't continue to drive, or you will clog (saturate) the canister with gas for sure. My wife's 05 Scion, check engine light w/ P0441,0442, and 0446.......cleared with my scanner, never came back after I tightened the gas cap
The 0400 - 04## are all emissions related, can be caused by something as trivial as an improperly tightened gas cap or as complex as the EVAPORATIVE EMISSIONS CONTROL SYSTEM, which has a series of hoses, purge valve and charcoal vapor canister filter controlled by the computer. Older cars normally develop leaks in the hoses that can be determined using specialized leak detection testing, normally not for diy level of repair. Most of the 0400 series codes will not affect drive-ability but should be treated ASAP
P0446 Evaporative Emission Control System Vent Control Circuit. The most common cause is the gas cap left off and someone drove the car or the cap was not fully locked it will set the code. Some other causes are leaking evaporative emission plumbing from the fuel tank to the engine compartment, someone changed the fuel pump and did not seal it properly. Failure of a emission component in the evap system. The only way to diagnost these is an OBDII scan tool and a smoke machine the light will come on when the computer does its test of the system and there is a hole as small as .020" 1/20,000 of an inch ! The light can only be turned off by a OBDII scan tool
Give me food and I will live give me water and I will die what am I?
What is 8 divided by 2(2 plus 2)?
A teacher walks into the Classroom and says If only Yesterday was Tomorrow Today would have been a Saturday Which Day did the Teacher make this Statement?
What is pokediger1s password on roblox?
Who was Hillary Clintons running mate in the 2008 presidential elections?
How do you get 1000000 robux for free?
What TV show was Precious and Few by Climax the theme song for?
A farmer has 19 sheep All but 7 die How many are left?
What is the toughest academic course according to the Guinness Book of World Records 2011?
Why do so many foods "taste like chicken"?
Who invented Lincoln Logs?
How did chickenpox get its name?
What is doomscrolling?
How did the Wiffle Ball get its name?
Do schools still teach cursive writing?
Can eggs break inside a chicken?
How is kottatchiyar in English?
What are good qualities of a resource mobilizer?
How is medium a factor in representing the filipino identity in a work of art?
How do you transulate happy independence day in konkani language?
How should the state react the violation of law?
Advantage and disadvantage of on premise catering?
Which scene from the Beowulf reading is a flashback?
What day is national godchild day?
Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.