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P0449 is back again!

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Old Apr 12, 2013 | 04:31 PM
  #1  
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Default P0449 is back again!

"The PCM has determined that a malfunction exists in the electrical circuit for the vent valve/solenoid in the evaporative emission control system.

Definition:
EVAP (Evaporative Emission System) purge/vent solenoid circuit condition

Explanation:
The solenoids and system wiring are monitored for opens or shorts

Probable Causes
1- Purge or vent solenoids defective
2- Check connevtor and wiring
3- Fuel saturated vapor canister
4- Failed EVAP vent solenoid


anyone else had to deal with this, any info/help is appreciated."

I copied this from another site and I have the same problem and I have been looking around a while now for the answer. I had this code before and replaced the evap canister twice due to this code and a related one aswell. It has been good for a few months now but it came back.

When I had this code the first time and other people did too we were both able to clear it and it would not come back for a while but not this time.

As soon as I clear the code it comes back on right away! So i am leaning toward a bad wire/connection some where. Any other thoughts or good places I should look for a possible split wire?

Thanks, -John
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Old Apr 12, 2013 | 04:54 PM
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Did you replace evap vent or purge solenoids?

Would check both of those and ohm out the wires for both back to the pcm. This is common on trucks that see lots of gravel road useage.
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Old Apr 12, 2013 | 05:00 PM
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I believe i just replaced the canister this doo-hickey

Also I have been having problems filling up for the past few months, the nozzle when go to fill up my tank will click(acting like its full) but its not. It seems like the gas backs up in the filler tube and triggers the nozzle click. IDK if these are related?
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Old Apr 12, 2013 | 05:28 PM
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That looks like the vent solenoid.

When my Tahoe clicked the gas pump off like that, it was due to a gravel road dust plugged vent solenoid and hoses leading to the charcoal canister. I had to take it all apart and clean it out.

I had a different code though, mine was for the valve not sealing or being plugged not the control curcuit like yours. I'm betting your problem is in the connector or the wiring back to the pcm on either the vent solenoid or the purge solenoid. Only way I know to check it is to find the pins on the pcm and ohm them out 1 at a time, will need to use a long jumper wire to reach everything.
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