Hi all. Hope there is still some action in the group. I have a 2007 Ion 2.4L. It has the EVAP error code P0449. There is +12 getting to the EVAP solenoid and I removed the solenoid and tested it with a 12 volt DC supply and it seems to be working. But the solenoid does not turn on while in the Ion. I can't seem to find a good diagram that shows me what part grounds the other side of the solenoid voltage to energize the part (that or the wiring is likely the problem). Appreciate any help.

Jay

 

Seems like whatever you were using as the ground or reference for your 12 volt actuation test on the bench is the most likely thing that is grounding it to the vehicle

 

One wire on the solenoid has +12v on it all the time (as it should). The other wire gets grounded somewhere when the solenoid is actuated. I know what wire needs to get grounded coming from the solenoid I just can't figure what component is suppose to ground it. Tracing the wires back through the big bundle of wires will be very difficult if not impossible. There is a relay, or other part, somewhere that grounds the wire when needed. Web searches have supplied all kinds of different data but so far none are exactly for my Ion.

thanks,
Jay

 

 

 

Code title/description states/malfunction.
If I remember correctly, the only time you want the canister vent valve open is when you are pumping gas so that the air you are displacing has somewhere to go as you displace it with fuel.
The test Andy mentions indeed runs once per drive cycle under the conditions stated. If the vent is not closed all the way when driving, it creates the equivalent of a pressure leak.
This is the same code that will be thrown if your gas cap is not installed correctly or the seal has gone bad (a few other things too but those are most likely. Bad seal at gas cap = pressure leak.

The ECM completes the electrical circuit by supplying the ground to the circuit at the front of the car (at the ECM). Between there and the solenoid is nothing but wire (not sarcastic).
You're getting 12V on one terminal so either the valve is sticking open after being actuated during the test (or not closing completely is a better way to put it, OR the valve is sitting closed the whole time due to a discontinuity in the wiring or the solenoid being defective.
Since bench tests indicate the valve is moving properly when the solenoid is grounded, the solenoid in the valve is not the issue.
Which pretty much leaves the wiring or the gas cap.

Personally, between the two, it is more likely to be a gas cap issue.
People have reported the connector at the solenoid or the wiring nearby had apparently received direct physical impact and the wire was physically damaged.to the point of no longer being connected.
There is no other reason that this wiring should go bad. If it is going to, the most likely place will be between the connector to the solenoid and where the wiring vanishes into bundle land.

If the vent solenoid is sitting closed all the time, you will likely have much difficulty putting fuel in the tank (wiring issue)
If it is gas cap related, the vent is operating normally while fueling, and the pressure leak is detected during the EVAP system test once per drive cycle. (gas cap issue.)

I don't think there is a way to monitor the vent solenoid position through OBDII. I think it is a "process of deduction" thing, where the fuel system can't pressurize back in the tank, leading to a "something's not right back here" P0449.
The question is why.

In your case, I would inspect the gas cap for nicks n the seal and inspect the top of the filler neck where it meets the gas cap seal for corrosion,

Although I don't like throwing parts at cars, throwing a gas cap at it usually makes this code disappear IF YOU ARE NOT HAVING PROBLEMS FUELING THE VEHICLE.
If you ARE having fueling issues, I would suspect the wiring.

 

Thanks for the info 02 LW300 and derf. Guess I mostly now know what I need to know but I need to study the PCM a bit. Hope to get back at it this afternoon. If not then this weekend.

02 LW300: It just kicks out a P0449 which is a generic EVAP solenoid error (I think). And of course turns on the check engine light.

derf: I don't like shotgunning parts either but I got a new gas cap yesterday afternoon and it didn't help. I always found it curious that my Ion didn't have a locking gas cap. So it was easier to justify replacing the gas cap as I now have one that locks. I am having no trouble fueling the Ion.

I'm going to double check the EVAP solenoid. I just checked that it made noise during the bench test and assumed that meant it was good. I didn't actually check for flow. Then on to the stuff you guys mentioned.

many thanks,
Jay

 

Take the old gas cap (if you kept it) remove the o-ring and clean the cap thoroughly. Clean the o-ring and filler neck and lube the o-ring with some WD-40 and reinstall it. Clear the code and drive the car for a while and see if the code comes back. I've never had much luck with aftermarket locking gas caps fitting properly.

 

Strangely enough I think I'm going through this exact situation myself.

And the advice I gave up above was incorrect as I now realize he was talking about the canister purge solenoid not the EVAP vent solenoid.

Know that I have soldered the pigtail on correctly, I do in fact get 12 volts on one side and relative to frame ground and as for the ground lead on the connector, I'd almost swear it is already a ground, meaning the valve should be actuated and held open which makes no sense unless this is by Design while in open loop. But the code only sets if the PCM senses the voltage is in the wrong state for something like 17 seconds straight, presumably looking for something that is improperly grounded or shorted to ground or shorted to voltage.

Of course my situation is hanging off of a quad driver module off of which everything else seems to work. I really do believe this has something to do with the dash and that this is all coincidence. I haven't worked on it in a week and a half between work and my wife being on vacation but home.

Also found the hissing noise when doing key on on the 95 and having to prime multiple times with a brand new fuel pump . Apparently the o-ring on the fuel regulator that sits in the rail dried out with no fuel in there for so long. I purchased a new one . If I remember that the fastening clip is a biatch, although I had the fuel rail out at the time and no way to support it. The fuel rail in this vehicle is plastic so applying too much force is not an option.