How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dave Nova Your Own Question
Dave Nova
Dave Nova, ASE Technician
Category: Kia
Satisfied Customers: 19451
Experience:  ASE Master Certification. 25 yrs experience
Type Your Kia Question Here...
Dave Nova is online now
A new question is answered every 9 seconds

Hello Kia techs. I have a p0446 vent valve circuit malf code

Customer Question

Hello Kia techs. I have a p0446 vent valve circuit malf code on a 2004 sedona. Customer states car starts to run poorly when fuel is about 1/2 tank and less. I pulled down the charcoal cannister and operated vent valve which works fine. There is B+ voltage at the brown wire at the connector to the vent valve and I'm about to check the continuity of the white wire from the the connector to the ecm. Am I heading down the right road or is there something going on I don't understand? Well I don't understand a lot, can you help? I am hoping to get help from someone who has experienced this as I already have access to wiring diagrams etc.
Submitted: 4 years ago.
Category: Kia
Expert:  Dave Nova replied 4 years ago.
Hello and thank you for trusting me with your question. My name is XXXXX XXXXX I will do my best to help you with your Kia problem.

Don't Forget, the deposit you placed to ask this question is not used to compensate me until you rate my service! Please remember that when you are asked to give a rating, you are rating My Service, and not this website itself or your vehicle.
This is not a wiring problem. If there was a problem in the wiring circuit, you would set a P0449 code. The P0446 code sets when the system does not vent properly. Most of the time this is due to the evap vent valve sticking shut intermittently. Before replacing the vent valve, check the tank vent line, charcoal canister, and line over to vent valve to make sure the line is not damaged (collapsed) or restricted in any way.

Dave Nova and 2 other Kia Specialists are ready to help you
Customer: replied 4 years ago.
I have cannister assy out and all the lines look and flow very well. Would this cause the poor running situation she has sometimes? I just hooked up a hose to the big metal pipe that connects to the char cannister (goes into tank) and blew in it and it pressurized tank and then released the pressure back out of the line very slowly. gas cap is off. For such a big line it is either restricted or has an orifice in it. Like I say, gas cap is off and tank seemed to pressurize and then release back slowly out of the line. Fuel filler must have a one way valve. Your thoughts thanks Jack
Expert:  Dave Nova replied 4 years ago.

There may be an orifice in the line. Most of the time when this fault occurs, it is just due to a sticking vent valve. The fuel vapors tend to build up a sticky varnish inside the valve. If the tank is not venting properly, it can make it harder for the pump to draw fuel from the tank and may cause driveabiltiy issues as well.

Customer: replied 4 years ago.
Guess I'll go with the vent valve. I can see that pipe going along the tank and then into another rubber line and that all looks good. Doesn't the gas cap allow air into the tank? How many times have I used you Dave? You're good. Thanks again Jackj
Customer: replied 4 years ago.
It just came to my attention that we put a new vent valve in this 45 days ago. Guess I need to drop that full tank and check that hose restriction. Don't you think?
Expert:  Dave Nova replied 4 years ago.

If the vent solenoid has been recently replaced then you should check restrictions.