Evap vent solenoid circuit error code p0446?

So, this code comes on when there is high resistance in the circuit, I would remove the connectors from the valve and the PCM to inspect the terminals for corrosion. Also here are the wiring diagrams for the EVAP system and a guide to help you do the tests.

https://www.2carpros.com/articles/how-to-check-wiring

Also, even though the valve tested good I would replace it anyway if you can't find a connection problem. Check out the images (below). Please let us know what you find. We are interested to see what it is.

Replaced the valve I clear the code 30 40 miles later comes back on. Now new gas cap new purge valve new canister vent valve still starts good runs good no bad idle no problem putting gas in clean underneath.

Is it the same code P0446? if so it is high resistance in the EVAP wiring you will need to go over the wiring and follow the guide I gave in the first post.

Yes, same code. It states evaporate emission system vent control circuit p0446? Can a mech with the right equipment trace the problem easier or is it trial and error. also, what will it hurt because it will take me sometime 2 get 2 it because of my condition right now. I have a test light and ohms meter that's it ????

Oops, memory bad , I did check out both purge valve and canister valve had positive and negative reading 2 connectors that plugs into units, so I did have readings through the system???

If the wiring looks good, I would try another vent valve, it is common for these valves to go bad. Check out the images (below). Please let us know what you find.

I replaced that vent valve so it is possible that it could be bad being new. When I replaced it, I zeroed out my odometer went 45 miles engine light came on?? About same as old one?

Another thing you should check is the vacuum and vapor lines from the fuel tank to the engine, check for cracks or leaks.

Okay, back 2 Sq one. all lines look good from what I can see without being on hoist. So, purge valve and canister valve are good. I clear the code drive 20 miles come home 2 days later drive another 20 25 miles engine light comes on again it is a sealed unit so is the vacuum leak when it sits under pressure, been sitting 2 days took the gas cap off did not feel any pressure release don't know if this makes any sense???

It sounds like the new gas cap is defective? the system must be air tight. The only other thing I can think of is if the canister is leaking, how did you check it?

I made sure there was power to the solenoid took the solenoid put 12 volt 2 it 2 make sure the piston opened and closed made sure I could blow through it when not activated. Is there any way I can check the gas cap. Like I said it sat 4 a couple of days took cap off could not feel any surge of pressure.

You should not be able to blow through it when not activated.

Getting valves mixed up I think the purge valve on the intake you cannot blow it is normally closed the canister valve by the gas tank is normally open until activated l believe I think????

Yep, that sounds right.

I think you may be on the right track about the gas cap. It is new but like u said it could be defective. It is from GM but a couple of things I tried points to it. I am going to order another one if it does not work, I am going to start from scratch after I order a vacuum pump so I can check everything. It will be a while before I will let you know what happens. Thank you for your help, made me understand the system, again thank you will be in touch.

No problem, let me know what you find.