p0446

[Brian Armour]

I've got a DTC, P0446, I went to buy another canister vent solenoid and plugged it in before I realized it had a different connection to the canister on it. But it did help in one way, it didn't activate when the truck was turned on either. When I tested the voltage I only get about 2.5 volts. I thought it should be about 12v. Is that correct?

Anyone have any experience on the wiring/circuit for these? I've had so many broken wires on this truck I'm quick to jump to the thought that its another. I just don't have any info on tracing and testing the circuit to diagnose exactly where tyne issue lies.

Any help would be really appreciated.

 

[Brian Armour]

So I probed the solenoid with 12v and it closes properly.

I found 4 more compromised wires and fixed them up.

I tested the red w/yellow wire for continuity at the purge valve and it has it.

The purple w/ white I can't find any further up than the wire chase by the drivers door and it has continuity there.

The purge valve also is getting about 2 - 2.5v.

I zip tied the hoses that I can get to around the canister pairs and spit lubed the O rings on those connections (gross) and I can't tell what else I could do.

I don't know the process to test the electric part of the circuit to know when/how the 12v get applied to be able to tell if my truck isn't energizing the circuit, or if I'm checking at the wrong time.

Does anyone have knowledge of how the vent circuit tests itself? If I know when there should be 12v I can test for it. If it does, then I will know its a vacuum leak and not an electrical issue.

 

[scott degroot]

You shoudl have 12 volts at the red/yellow wires on both of those solenoids. They get power from fuse 32 in the underhood fuse box which supplies alot of other sensors as well. Find out where you are losing power adn we'll go from there.

 

[Brian Armour]

I'll check that out today and see what I can find.

I know the vent solenoid should normally be open right?

12v will cause it to close, so am I correct that the supply of 12v is only a temporary test cycle and that a lesser voltage to leave the solenoid open is the norm?

 

[scott degroot]

You are correct in that the valve is normally open however the valve will always have 12 volts going to it. The pcm controls the ground side of the valve to close it.



One thing to remember when it comes to things like this is that the there will typically always be power to a device, the pcm controls the ground side. It is designed this wasy because it is easier on the computers to control the ground side as opposed to the hot side.

 

[Brian Armour]

We had rain and snow all day yesterday, so I never got out to crawl around.

I did however manage to get the Ford workshop manual and the wiring diagram manual. So I'm a little better equipped to trace the wires, or at least now I see where they are supposed to run.



I see where the line connects to the fuse and to the pcm so I'll start at the fuse end to see if there's 12v there. hopefully there is and its just a matter of some tracing to find the issue.

 

[Brian Armour]

So I did so work on it today.

Tested at the battery junction box and got 12v at fuse 32.

Pulled the bob out and probed the wires under it and it had 12v. Uncovered the 1 to 3 splice (s111) in the harness and probed the 3 legs and found 12v on all 3.

Confused, I then checked the evap purge and canister vent connectors and both had 12v now.

So I buttoned it back together.

I didn't do anything beyond testing and probing the wire so I didn't fix anything but now I get a 12v reading. I think it points to a possible problem around the BJB but I don't what/where as it seems to be giving the proper voltage ATM.

I'll see what happens when I drive around in it tomorrow. No code, or return of the code.

 

[Igor Smetaniuk]

I get the small leak code too and have just been clearing the fault codes with the Bluetooth OBD11 adapter and Torque app on my smartphone because I've never been as ambitious as you to do some electrical diagnostics. I'm definitely not going back to a Stealership for a smoke test at $95/hour. They said it needs to be isolated in 3 different areas which could total about 3 hours worst case or $285. That's just the diagnostic fee.



The Evap system can take many miles to reset which I was told by the Dealer and turned out to be true after I cleared the fault code (CEL). All 4 times that I've done this, It has been between 650-900 miles before the CEL kicks back on for the leak code.



Don't get overly excited if you don't see the CEL come back right away. I'm expecting mine to trigger again as I'm just under 800 miles. I'm sick and tired of this petty nuisance. I bet the "small leak" of gas fumes is comparable to a mosquito fart let alone damage the environment.



Great thing about NY emissions is that they allow one system to be 'incomplete' to pass and get my sticker. I've cleared the CEL light/fault a day before inspection and drive away with my new sticker thinking :cheeky:



I wish there was a cheap alternative to a smoke machine. I even considered looking up an old friend who smoked pot 24/7 so he could exhale in to the tubing.



Make sure to replace the gas cap as that could trigger the fault.



Good luck with this hard to find pain in the A** problem.

 

[Brian Armour]

ugh... so today when I started it I got a p0443 code for there purge circuit.

no idea on how it changed, but I've got tomorrow off to deal with it.

I soo wish Mass's inspection gave us a mulligan on a test.

 

[Brian Armour]

Soo... just to throw myself under the bus here.

I didn't get the evap purge connector all the way on when I was getting it all together.

I connected it, cleared the codes and drove it around a bit today.

After a bit of driving I checked and the evap monitors are not ready yet, so theres still more driving to be done. Hopefully it and the catalyst sensors OK themselves up w/ no codes and I can get my sticker.

Im tired of tensing up when I go by cops lol.

 

[Brian Armour]

Soo... just to throw myself under the bus here.

I didn't get the evap purge connector all the way on when I was getting it all together.

I connected it, cleared the codes and drove it around a bit today.

After a bit of driving I checked and the evap monitors are not ready yet, so theres still more driving to be done. Hopefully it and the catalyst sensors OK themselves up w/ no codes and I can get my sticker.

Im tired of tensing up when I go by cops lol.

 

[scott degroot]

The evap monitor will not run after the codes have been cleared until the vehicle goes through a cool down period which is overnight.



Typically I can get these to run all the monitors within about 5 miles after a cold start.

 

[Brian Armour]

It's still not set.

I've run around town and the highways since I reset it.

All of the other monitors are OK, just left with the evap being incomplete.

 

[Igor Smetaniuk]

Mine has never kicked the code until I've put alot of miles on it after clearing. I'm over 900 now and counting. I know it's going to come back on it because it never fails to haunt me.

 

[Brian Armour]

So it turns out that Mass has a mulligan too!

To quote:



" To pass the emissions test:



2000 model year vehicles may have a maximum of two (2) ?not ready? non-continuous monitors.

2001 and newer model year vehicles may have a maximum of one (1) ?not ready? non-continuous monitor.

If the vehicle failed the emissions test with a catalytic converter-related diagnostic trouble code, the vehicle?s catalyst monitor must be ?ready? to pass the retest."



The Evap apparently qualifies as "non-continous". So as long as you don't fail a test because of a code, you can pass with the monitor incomplete or not ready. If you fail because of the code, then that monitor HAS to be ready to pass. So just don't go with a bad code first and you can be okay.



Along the way today I found 2 more electrical issues on the truck, corrosion inside connectors.

This truck easily has the worst condition for wiring I've ever run across. But for today, Ive got my sticker and my dash is dark so I'm a happy guy.

Once again I am thankful for all the help.

 

[Igor Smetaniuk]

COOL! You're welcome and now legal again so you can take you're time fixing that absurd Evap system nuisance bullcrap. It's a great trick to know when you get a dreaded CEL which always seems to happen when it's time to get an inspection.



I saw one YouTube vid where a guy purchased a Chauvet Hurricane 700 smoke machine on ebay for $35.00 ? the kind a basement rock band would use or smokin' your porch for Halloween. It's cheap enough to where I may give it a shot to hunt my leak down. If it works, it sure would be cheaper than one of those expensive ones the mechanics have.





Here's an amusing explanation of Evap system and the various code meanings



https://www.youtube.com/watch?v=Dfj-F_pTj5M



Interesting info regarding one leak possibility in the Evap system in our Explorers that is more difficult to access.



https://www.youtube.com/watch?v=UzMsZmU2pho