CB2003Suburban

My 2011 got a check engine light. Code P0449 EVAP System Vent Valve/Solenoid Circuit. I have changed the gas cap and the EVAP purge solenoid under the hood and I still get the P0449 code. WHat else could be causing ths?

oilcanhenry

Did you clear the code, and then it still came back? Old trick sometimes works: disconnect the battery for a time and reconnect it. Might work.

mountainmanjoe

Why did you change the purge solenoid if the problem is with the vent system?

CB2003Suburban

YEs, I cleared the code out after I replaced the solenoid. The check engine light came back on a short time later. I did not try to disconnect the battery yet.

As for why I changed the solenoid is because when I looked up the code that is what it said was the issue, the solenoid valve. I dont get any other codes, just the P0449. THe scanner tool I use says the solenoid id the issue also.

"When error code P0449 appears, this indicates that the EVAP system vent valve solenoid is malfunctioning"

mountainmanjoe

that's right ... vent valve.
You said you changed the purge valve solenoid. Completely different parts.

CB2003Suburban

Ok, I see now. My bad I probably changed the wrong part. I will check the Vent Solenoid on the canister this weekend. Hopefully that will cure it. Thanks for that picture, that helps alot!

CB2003Suburban

I had the Vent Solenoid replaced on the canister and the problem still persists. Cant clear out the code. On the scanner there are 3 instances of the P0449 code. 2 pending and one permanent. The shop I took it too went thru a bunch of tests. He found a bad wire, fixed that and the problem is still there. He can get the new vent solenoid to switch on and off by switching it with probes so the vent sol should be ok. He thinks it may be the ECM not telling the vent sol to go on & off as it should. Does anyone else have any ideas as to what the problem may be? So far I replaced the Solenoid under the hood, my mechanic replaced the canister vent solenoid and fixed a broken wire. We're at a loss. He's gonna research it further and see if he can come up with any new ideas, but I would appreciate it if someone here had any new input into it. The car currently has 157k miles on it. I also replaced the Throttle Body about 2 months ago because of a faulty TPS. Would that have any bearing on this?

Thanks for any help
Chris...