P0449

[05subur]

I have a 2005 Suburban. The check engine light came on and the code said P0449 Evap Emmis Vent Valve Sol Circut. I can trigger the purge valve -under the plastic engine cover- with 12 volts. I cleaned out the canister (only dust) attached to the vent valve -by the gas tank-, but could not trigger this valve with 12 volts. I read more topics and everything seems to lean towards a new gas cap. Before giving Chevy my money, I covered the gas cap vent with plastic wrap. THE LIGHT WENT OUT. So I bought a new cap. The light CAME ON immediately. My question is, am I missing something? Did I get a bad cap? Is it the vent valve. The vent valve wouldn't trigger but the plastic wrap turns off the light?

[05subur]

Thank you very much for the reply. I won't be "jumping" anymore. I'll re-check the connections and/or replace the vent solenoid valve.

Thanx again.

[Supertech64]

P0449 has nothing to do with the gas cap or sealing(that would be a P0442 most times). Also has nothing to do with the purge valve(would set a P0496 most times, also I must add that jumpering 12v sounds like a bad idea, I think thats 5 volt/PWM and goes to the PCM) under the hood.

 

It has to do with the vent solenoid driver commanded state and actual state not matching.

 

 

 

Most of the time(can't say yours for sure) it is the vent solenoid valve or the wireing/connectors. There are a few topics on this code that were being discussed a week or two ago in this forum.