Evaporative emissions control vent circuit low= p0446
1) Make sure the gas cap is ON (and "clicks" ) and is the correct Toyota Gas Cap (aftermarket may not work). Clear the codes and run for a while. See if codes come back.
2) Make sure the tube to the electrical valve on the air cleaner is still on - Many clumsy oil change places pull these off accidentally (or on purpose- who knows?)
3) Test and inspect all the rubber lines under the hood and connecting to the canister.
4) Test the VSV Electrical valve on the canister - put 12V across it using 2 small alligator clips and wires (RadioShack) It should click and let air through.
5) Test the other 2 valves under the hood the same way (the one on the air cleaner works backwards i.e. Power = Block Airflow)
6) If you can - test the air valves (seen above) -
7) Bend over - get your wallet out and buy a new Charcoal canister - ouch! $300+ If you are still getting the "whoosh" on taking the cap off, maybe the Pressure sensor in the tank is bad.
P0446 Evaporative Emission Control System Vent Control Circuit Malfunction
Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied Batt. voltage with key on. The ECM's driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open,or a short to battery voltage on the control circuit, P0446 will set. Code also may refer to ECM detecting that EVAP system is unable to achieve or maintain vacuum during test.
SymptomsThere will be no obvious symptoms to driver, other than MIL illumination.
CausesA code P0446 could mean one or more of the following has happened:
Possible SolutionsWith a P0446 OBD-II trouble code, here are some things to try:
Po446, toyota tsb ref # eg022-06 (issue date 4/11/06)- remove gas cap and check fuel fill pipe for corrosion, check seal on gas cap for damage from corrosion on fill pipe. Replace fill pipe and gas cap.
SOURCE: p0446 code
Hi, check out this article, it's detailed on what to check: http://www.obd-codes.com/p0446
SOURCE: check engine light on,results in code P0446-fuel emission cotrol
Well it could be as simple as a new gas cap, or clean seal on it & tighten again. There are a few other items in the system too, but one common one is the vapor canister gets plugged up with dust & dirt.
SOURCE: Evaporative Emmission System Malfuction----p0446
Possible leaks, clogs, malfunctioning VSVs (vacuum switching valves), and faulty Evap charcoal canister. This system is designed to remove harmful vapors in the fuel system and preventing these vapors to enter the atmosphere, regulate fuel pressure, by sending it into the combustion chamber to be burnt.
Diagnostics for P0446:
1. Inspect vacuum hoses and pipes
between EVAP (Purge) VSV and
Charcoal Canister for leaks.
2. Replace Vapor Pressure VSV and
Canister.
Hopefully this helps
SOURCE: check engine light is on
you hav egr valve problems n evap emissions flaws-ull need a repair manual if ur the mech-buy one at a parts place-clymer n haynes r the best
SOURCE: check engine code "P0446 Evap Control System Vent Control Circ"
Unfortunately, this code has nothing to do with the gas cap....
A code P0446 could mean one or more of the following has happened:
Here are some things you could try to fix it:
Symptoms
There will be no obvious symptoms to driver, other than MIL illumination.2,269 views
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