P0446 - Help Please

[CU_14SierraAT]

Recently bought a 2014 Sierra All-Terrain package with 48,000 miles. I love the truck but recently got the p0446 code. (Evaporative emission system vent control circuit). 

 

So far I have cleaned all the lines and the vent valve. I don’t want to start replacing things without knowing for sure what will fix it. Any help with this would be greatly appreciated! 

[CU_14SierraAT]

Bump. Anyone? 

[CaptainMcFunk]

I get this code about once every 2 months or so, and I just clear it and move on.  I haven't been able to replicate it under any specific instances, so i'm not really sure. I know that's not helpful, but i'm glad to know it's not just me getting this code!

[CaptainMcFunk]

After a quick google, it appears the fix is to replace the valve:  

 

https://www.samarins.com/glossary/vent-valve.html

 

Some GM trucks were known to have this problem which causes the code P0466. The repair includes vent valve replacement and some modification of the vent valve setup.

[4weight]

I got this code on my AT shortly after buying it at 30K.  I literally had an appointment at the dealer.  I was out on a deer hunt on a country road and floored it. Had never got on the truck since I had bought it.  Got to about 100 mph and took it down.  Looked down, check engine light went off.  Blew the soot out of it I guess.  Service tech said it could have been a number of things, clogged filter, valve, etc.  Said it is a tough code to figure out what to replace.  All I know is it has never come back on.  39K now.

 

Good luck, go haul ass and see if it works............LOL.

 

4W

[CU_14SierraAT]

Thanks for the replies. I’ll try flooring it first, if that doesn’t work I’m going to replace the vent valve. If that doesn’t work I’m going to replace the fuel tank pressure sensor and if that doesn’t work I’m just going to reset the light every time it comes on lol.