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Scott W.
Scott W., Ford Technician
Category: Ford
Satisfied Customers: 3311
Experience:  28 yrs. experience as Ford ASE Master Technician. Accolades include being a 2005 Ford PTS Regional Finalist and 2006 ASE Ford National Technician.
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2007 Ford F-150: the check engine light is on..P0446

Customer Question

I have 2007 Ford F-150 and the check engine light is on. The code is P0446 can you help?
Thanks
Submitted: 5 years ago.
Category: Ford
Expert:  Scott W. replied 5 years ago.

Steve W :

Hello my name isXXXXX the code P0446 is a cicuit malfunction of the evap vent valve, it could be PCM, wiring issues, or the vent valve itself. The first thing that should be done is inpsect the vent valve and make sure it is plugged in and no corrosion in the connector. The vent valve is located above the spare. Here are some pictures. Any more questions just ask, Thanks Steve W

Steve W :

I can give a pinpoint test, but it requires some special testing equipment and the test is rather hard to copy and upload.

JACUSTOMER-olpoion9- :

I will check the vent valve and get back to you. thanks

Steve W :

Thank you

JACUSTOMER-olpoion9- :

The connector is plugged in and no corrosion

Steve W :

Ok, let skip the wiring check, check the resistance of the solenoid and see if it falls in the rnge of this:

Steve W :






  • Are the resistances between 48 Ohm - 65 Ohm?

  • JACUSTOMER-olpoion9- :

    will do. can I continue this tomorrow?

    Steve W :

    Sure, I am online after 6pm central, Thanks Steve W

    Customer:

    thanks I will check and get back to you

    Customer:

    The solenoid is ok

    Customer:

    hi steve

    Steve W :

    Hello

    Customer:

    I checked the solenoid and is ok

    Steve W :

    Ok, good, the pinpoint test wants the output from the computer tested, basically checking the driver and pcm wiring all at once. Do you have a scan tool that can turn on the vent solenoid?

    Customer:

    no...I am a weekend do it yourselfer

    Steve W :

    Ok, I will see if i can find a wire diagram for you, you are going to have to check our the wiring and see if you can find the problem with these ciruits.

    Customer:

    ok

    Steve W :

    Try looking at the wiring from rear to front tracing the wires, see if you can see any place in the wiring that looks green or corroded.

    Customer:

    I traced the wires today they all looked ok

    Steve W :

    Here is a diagram of the wiring, check the fuse in this circuit, maybe you will get lucky and it will be blown.

    Customer:

    I did not get the diagram

    Steve W :

    Try again

    Steve W :

    Sometimes takes a couple minutes

    Customer:

    are you sending a link?

    Steve W :

    Wow, that was weird, was there, now gone, I'll try again.

    Steve W :

    Click here

    Steve W :

    Did you get the diagram?

    Customer:

    yes the fuse would be the 7.5a in the cjb?

    Steve W :

    Yes, you should have power back at solenoid at all times, you can check the fuse, then go back to connector, this will let us know if that wire is good.

    Customer:

    thanks I will check and get back to you

    Steve W :

    Ok, I am going to BBgame tonight, will check when I get home, Thanks Steve W

    Customer:

    when I reset the ck engine light it stays off until I shut the engine down and comes on when I restart ....does this help?

    Steve W :

    The light usually won't come on until a key cycle, normal operation.

    Customer:

    ok thanks enjoy the game

    Steve W :

    Thank you, XXXXX XXXXX have power back at the solenoid, then you are dealing with one wire only.

    Steve W :

    No power to solenoid, then this supply wire is open if the fuse is ok.

    Customer:

    There is power at the solenoid checked both wires at the plug also good

    Customer:

    could the evap canister purge valve cause this problem? If so how do I check it?

    Steve W :

    No, the canister purge solenoid would set another code. Here is contunuation of the pinpoint test, it involves checking the wiring.

    Steve W :

    HX33 click here

    Steve W :

    Since you have power to solenoid, try grounding the violet and white wire, the solenoid should click, if not make sure you still have power when gounding the circuit, you could have power there, but not be able to flow the current. You can test for power at solenoid using a headlight bulb and see if it lights, if it does, then we know the power supply is capable of handling the current flow.

    Customer:

    COMPLETED THE ABOVE ALL CHECKS OUT

    Steve W :

    If this pinpoint test passes also, then you should take the vehicle to a dealer or shop that has a scan tool that can perform active commands, and turn on the solenoid to test the driver in the PCM, any more questions just ask, Thanks Steve W