So I've got an engine light on, and I used the ELM 327 Mini OBD-2 scanner and bought the OBD fusion app for android os. The diagnostics scan showed the error code P0446 which is an Evaporative Emissions System Vent Control Circuit. Does anyone have any past experience or insight on how to go about troubleshooting and/or solving this?

 

Faulty, missing, or broken gas cap, faulty EVAP system hose, leaking fuel tank or a busted charcoal canister. are likely issues.

 

the vent solenoid may be faulty.
-with your scan tool; turn the vent solenoid on and off...you should hear it click as it closes and opens. if not....
-remove the vent solenoid connector
-one wire should have battery voltage at key on...use a test light to grd
-jumper the test light across the 2 terminals in the connector
-with your scan tool...turn on the vent solenoid...the test light should light up. If it lights up...replace the vent solenoid.
-

 

I too have this code.... I replaced gas cap and also the purge valve and still code returns. Is the charcoal canister a difficult part to replace? I looked on auto store website for my vehicle and did not see a charcoal canister listed (2001 Impala 3.8) but I did find a vapor canister.... is tis it? ... https://www.autozone.com/engine-mana...126/577567_0_0

 

the vent solenoid may be the problem not the purge solenoid. check the vent solenoid b4 replacing a cannister.

 

Thanks....is the vent solenoid attached to the canister? I ordered a new vent canister online yesterday an dit arrives today since it was a fairly cheap part and easy to replace with only one electrical connection and one hose attachment

 

Actually this is the part I bought thinking it was the canister but it is the vent solenoid. So where is the canister located?

 

follow the hose from the vent solenoid...it leads to the cannister.
make sure you can blow thru the hose..its should have a very slight restriction. a large back pressure means the cannister is clogged.

 

Thanks.... yeah the canister I believe is th emost expensive part so that will be the last part replaced. If the Solenoid replacement does not do it today then I will check all of the hoses also ... fingers crossed

 

Well replaced the vent solenoid the other day - check engine light came back on in about 2 days. I guess the only thing I have left to check is the canister