I hate emissions codes! P0446

[pmax]

Originally Posted by Bob Kontak

I often find surface rust on the gas cap o-ring sealing surface on the filler neck. I stuff a rag in the hole in case of sparks, which is seldom, and use a small cup brush on a die grinder. I also use a touch of dielectric grease or Syl-Glide brake lube on the o-ring if an old gas cap but usually just buy a new one for $12.

No gas cap rust problems in NorCal !

Critters chewing thru the wiring harness to the vent valve, yes.

[gsxrken]

I hate them too. Usually happen right as the annual NYS inspection is due, and the car won’t pass with it on. Clearing the code just before the visit doesn’t help either b/c the computer “knows” it was just cleared and must complete a few drive cycles.
So some $300 BMW secondary air pump or the like needs to be identified and swapped out before it can get inspected. I don’t mind addressing misfire codes but the gas cap stuff gets criminally expensive on an older car.

[cabmandone]

Well! That didn't work. Light came back on this morning while idling in the driveway. Oh well, she's back at school. When she comes home next weekend I'll put it up on the lift and start checking things. I'll start with the fuse but I'd think if it's bad that it would have done it on the shakedown cruise I took yesterday.

[fastfredracing]

I was waiting for this post. That code description is a circuit fault code, the pcm , is either seeing an open circuit, short, or lack of power or ground . You will find your answer by pinning out voltages at the ecm, and component .
Welcome to my world .

[cabmandone]

Originally Posted by fastfredracing

I was waiting for this post. That code description is a circuit fault code, the pcm , is either seeing an open circuit, short, or lack of power or ground . You will find your answer by pinning out voltages at the ecm, and component .
Welcome to my world .

As I understand it, the ECM tells the solenoid valve to close periodically. So how do I go about verifying voltage at the solenoid without a diagnostic tool that can send a command to cycle the solenoid?

[Bob Kontak]

Originally Posted by cabmando

As I understand it, the ECM tells the solenoid valve to close periodically. So how do I go about verifying voltage at the solenoid without a diagnostic tool that can send a command to cycle the solenoid?

Voltage may be there all the time but ECM creates ground when it's to close.

There is also the purge valve probably in the engine compartment. Solenoid on that can fritz. What size engine?

[pmax]

P0466, yeah that’s gonna cost you extra, can you leave the car overnight ?

[pmax]

Vent valve circuit dude.

It says so in the description.

First find the vent valve.

[Bob Kontak]

Originally Posted by pmax

Vent valve circuit dude.

It says so in the description.

First find the vent valve.

Yep yep. You are correct, Sir.

[pmax]

Originally Posted by Bob Kontak

Yep yep. You are correct, Sir.

Happens to be a path I have taken before, hence the critter reference, how the hell did they jump up couple feet ! Wrapped the replacement splice with black electrical overwrap in case it’s the color which caught their attention. But soldering while laying on your back was a new experience not to be repeated I hope.

[cabmandone]

Originally Posted by Bob Kontak

Voltage may be there all the time but ECM creates ground when it's to close.

There is also the purge valve probably in the engine compartment. Solenoid on that can fritz. What size engine?

4cyl 2.5L The valve I changed Is the one that goes into the intake. It's referred to as the vapor canister purge solenoid. From what I've found, there is also purge valve possibly back by the fuel tank at the charcoal canister.

[Bob Kontak]

Originally Posted by cabmando

4cyl 2.5L The valve I changed Is the one that goes into the intake. It's referred to as the vapor canister purge solenoid. From what I've found, there is also purge valve possibly back by the fuel tank at the charcoal canister.

The vent valve is the one in the back with a solenoid. It's open all the time to vent air after it's scrubbed by the charcoal. It closes when the system is periodically checked for no leak integrity.

I'll look and see where it is.

[cabmandone]

It looks like it's back at the charcoal canister by the fuel tank. I replaced the purge valve... not the vent valve. Friggin fraggin!

[Bob Kontak]

[Bob Kontak]

This is the purge solenoid. Suspect the one you replaced?

[cabmandone]

Originally Posted by Bob Kontak

This is the purge solenoid. Suspect the one you replaced?

Yep! I screwed the pooch! I searched vapor canister solenoid valve and the results only came up with the purge valve. I thought.. "must be the same thing!"... NOPE. Oh well. I found a vent valve for $58 shipped (Doorman) through ********* and another for $48 (Airtex) through stockwise auto. I'll probably order one. That way I have it on hand if there's nothing visibly wrong with the wiring.

[pmax]

Make sure you put it in writing !!!

[Bob Kontak]

Originally Posted by pmax

Make sure you put it in writing !!!

I think he just did.

I usually rig up a battery with wires under the car and put 12V to the valve. They usually never click because so often the problem. Ohm meter works too. Don't know the ohms but if you touch the terminals and it says a big "1." you are getting warmer.

[cabmandone]

Originally Posted by Bob Kontak

I think he just did.

I usually rig up a battery with wires under the car and put 12V to the valve. They usually never click because so often the problem. Ohm meter works too. Don't know the ohms but if you touch the terminals and it says a big "1." you are getting warmer.

I'm not afraid to put my mistakes in writing. I should enter this in the mistake thread here. I know there's one somewhere.

I watched a video on testing the solenoid. They just used a 9v battery but I have a way to put 12v to it.

[pmax]