446 trouble code

As i was leaving this morning , the check engine light came on and stayed on. I have a 2003 chevy silverado . Check code it showed P0446 .


Evaporative Emission Control System Vent Control Circuit Malfunction


can anyone help and help me find why it came on!

Thanks

do you have any mods done to the truck

I have the same problem with my 2000 Tahoe. I've reset the code and it came back about 3 days after. Today I took off the EVAP vent solenoid, located by the gas tank. There was a bunch of greyish soot that fell out. I took the rectangular cannister attached to the soldenoid off and found a sponge with a bunch of grey matter on it too. I tried to blow thru the pipe fitting, but couldn't. I also applied 12v to the terminals and could hear the solenoid click, but still couldn't blow thru it. I bought a new one and installed it. This all took about an hour. If I don't post back, this solved it.

Ryan