P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction

[lerndoutofnesscity]

Where and what should I be looking for to fix this code?
(P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction).

I have a 2000 Buick Century with a 3.1L engine

[BNaylor]

Originally Posted by lerndoutofnesscity

Where and what should I be looking for to fix this code?
(P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction).

I have a 2000 Buick Century with a 3.1L engine

Using GM terminology odb-ii P0449 DTC error code for a 2000 model year GM 3.1L is Fuel Tank Vent Circuit Fault. The DTC will set when the PCM checks the output driver for electrical integrity and sees that it is invalid. The output driver feeds the vent solenoid located at the evaporative charcoal cannister. It is not a common evaporative emissions fault but is PCM module related although I believe external circuits could cause the test to fail.

[mechbabe713]

Originally Posted by lerndoutofnesscity

Where and what should I be looking for to fix this code?
(P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction).

I have a 2000 Buick Century with a 3.1L engine

did the code pop up right after u filled your gas tank up with the car running? if so just clear the code. if not just start at the simplest thing and work your way up... see if your gas cap is on tight and start checking for leaks in the canisters and fuel tank

LB

[arlonadkinson]

07-24-2009, 03:30 PM

Check engine P codes! Chevrolet uses an EVAP solenoid that is located under most vehicles near the gas tank and connects to the charcoal filter can. Codes can be set and will drive you crazy trying to figure out if you have a bad gas cap, broke lines---this is where they try to get you to do a smoke test, or you just think the vehicle is no good! Relax, it is usually an easy fix and one Chevrolet has known about for years but continues to make easy money off people who cannot do basic maintenance. Now one code that comes up is usually P0449, along with maybe a warning to check the gas cap to see if it is on tight! Chevrolet will gladly read this code out for you for around $98.00 and then fix it for another around $100.00 which includes the EVAP part which if you buy at their parts dept. will cost you $32.00 and my dealership parts man told me they sell one a day! It is easy money for them and obviously a defective part they keep using for the last 10 or 15 years but hey, its money in their pocket. Here is how to fix it with ONE single common screwdriver! Get under the vehicle after putting on the parking brake and if you a little hefty, then removing the spare tire on the Chevrolet Avalanche will give you lots more room. The EVAP solenoid is easy to spot near the gas tank and it has one electric connector which disconnects by releasing the plastic clip and pulling the connector out. It also has ONE air line connected which goes to the charcoal cannister which also can be removed with the one screwdriver. The whole EVAP solenoid and air can can be removed with the screwdriver which makes it easier to unpolug the electric and air line. Get a replacement from the dealer as they certainly are familar with this part as they sell LOTS of them. Then just go under and plug the new one in and the problem is solved. Now if you do not have a tool to reset the codes, try the local parts places as most of them will do a reset for you, especially my favorite place, called Pepboys! If you do not have someone to do it, it can be done simply be removing the RED, positive lead off the battery and wait a minute and then plug it back in! The codes are reset but of course now you have to reset the radio and clock stuff! Chevrolet put this unit under the vehicle I guess so it could collect enough dust to fail after the initial 36 month, 36,000 mile warrenty! Course the new part is guaranteed for ONE year so keep all the old parts in case you have another failure in ONE year and you can exchange them for another new one! Not to bad to have a spare! They should have recalled and replaced this unit years ago but who is gonna make them? They make money out of this little defective unit and still have no idea why they went into chapter 11 bankruptcy and are headed for chapter 7 if they fail to get connected to their customers and quality! This one little item is enough for a person like me who bought this 2005 Avalanche Z71 and who thinks it is a great truck to NEVER ever again buy a GM product!

[grant_s_scott]

Thank you so much you saved me. $150 for the valve plus $115.00 to put it in. Faulty vent valve for emmission system. What a rip off. Good thing I checked online.

[adamstim21]

I have a 2006 Impala SS and this code just came on last month. My mechanic told me to replace the Evap Canister. Did that, then reset the computer. 1 day later the light came back on. What else should I be trying?

[BNaylor]

Do you have the 5.3L V8 engine? Other issues could be the vent solenoid by the evap charcoal cannister that you replaced or the purge solenoid located engine side or any of the vacuum lines to these components.

[adamstim21]

Yes 5.3 V8.

[BNaylor]

For the P0449 DTC first check the vent solenoid and connector/wiring. Located by the cannister. The DTC indicates a circuit control issue. The commanded state of the driver circuit in the ECM/PCM module and to the component control circuit doesn't match.

[adamstim21]

I'll try to check the wiring out. What exactly is the vent solenoid? Plastic part, metal part., etc.?

[BNaylor]

It should be located above the evap cannister. A square plastic component with vacuum line fittings and an electrical connector. You will see the lone wiring harness going to it. For most GM cars you have to drop the evap cannister to replace it. All of this can be accessed via the rear quarter panel back by the gas tank and driver's side filler area. From underneath.

Good luck and you're welcome.

[heartless2]

would this problem cause the ECM fuse to blow when put in gear??

[waterski182]

Great advice on this from the person who explained you can fix with a screwdriver. Make sure to order correct solenoid vent valve by checking 8th letter of your VIN, and with a flathead screwdriver, I made repair in 5 minutes. Was located underneath Yukon behind fuel tank and towards the center, right in front of rear dif. Reset code after repair and drove many times, and never came back on. Part cost, $35, my time 5 minutes. Dealer quote $380..of which they said $270 in parts. What a rip...do this one yourself if you get code P0449..