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Skyvisions, ASE Certified Technician
Category: Toyota
Satisfied Customers: 14504
Experience:  Toyota Master Diagnostic
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evaporative emission control sys vent control circuit malfunction

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evaporative emission control sys vent control circuit malfunction on 2002 Camry SE

Do you have a specific code number that was set in the computer? What part of the country do you live in? How many miles are on the vehicle?



Customer: replied 7 years ago.


The "Check Engine" light lit up on the dash. The vehicle was put through an emission safety test as required by the SDtate of Tx Annually and the test failed due to sys vent control circuit malfunction...I do not know how to ascertain the specific code number from the computer.


I live in Houston Tx and there are 54000 miles on the vehicle.

If you can get to a nearby auto parts store such as AutoZone they do free engine code reads. With the engine code number specifically I can give you better input on what a solution to your problem could be. There are several known issues for evaporative vent control systems or emissions related problems on this vehicle. Let me know if you can get the code number and we can proceed. Even if the check engine light is not on at this time there is a possibility that it is still stored in the memory of the computer unless they cleared the code. You can even rent generic code readers or you can purchase one for less than $70 these days from most part stores.



Customer: replied 7 years ago.


O.K. I will do that and get back to you

Let me know when you're ready to proceed with the code number. I will be monitoring most of the evening. No need to reply until that time.



Customer: replied 7 years ago.

If I had just known where to look, I had the code already printed out with emission failure report.


It reads: P0446 "Evaropative Emiss Control Sus. Vent Control Circuit Malfunction"


can you help?


This code relates to three possible scenarios. The most common problem was with the close canister valve which is mounted onto the side of the top section of the air cleaner box. There are two rubber hoses and one electrical connector going to the valve. Service bulletin number EG013-03 address the issue with this code and this particular valve. Air would leak past the seal in the valve causing the system to not pass the evaporative emission purge test. There also was an updated fuel tank filler neck to deal with a leaking issue also but given the age of the vehicle that should've been a problem early on as opposed happening now. Plus it would set multiple other leak codes so we probably can rule that problem out. That service bulletin was number is XXXXX The third issue is the vacuum switching valve that mounts to the charcoal canister itself. Unless you have a lot of specially test equipment is difficult to isolate and test these valves. If you do not have any way to test or check these valves the one at the air cleaner is the most common failed part and is very easy to replace. I do not normally recommend parts replacing to repair a vehicle but sometimes given the diagnostic charges that can apply this might be the only alternative that you have. Let me know what you find



Skyvisions and 2 other Toyota Specialists are ready to help you
Customer: replied 7 years ago.

Well everything went well as far as replacing the valve.


Only thing is no one told me the vehicle needed to be driven 70-80 miles for sensors to reset (I am now told) before reinspection of the emission system. It failed again and I only had one free reinspection. Now I have to pay an additional $39.75 to have inspected after the required miles are driven. The check engine light is out, was reset when I disconnected the battery.


I am accepting your answer as it was right on but wanted you to know in case anyone else has the same problem they could be told to drive vehicle 70-80 miles to allow all sensors to reset before having inspected again.

It is not the mileage so much as it is temp of the engine and the outside temp. Most people do not understand how the system works and usually it never is an issue because they never go directly to the echeck. Sorry for the inconvenience. If the temperature where your at is subzero it may not even run the tests at all because if it's too cold for the evaporative emission systems. On these older vehicles it won't run below a set temperature. This may affect some of the readiness test especially for the evaporative emissions.