04 Ranger-CEL code P0446 question

[mrmordun]

Starting to do the the run down on this. Fuel cap is good, all vacuum lines appear good so far. I at the point where I getting ready to check the canister purge valve, now I'm a bit confused.

I see that there is a Vapor Canister Purge Solenoid and a Vapor Canister Vent Solenoid available.

I thinking the vent solenoid is the small part back by the fuel tank with a 3 wire connector and the purge solenoid is the one under the hood with a 2 wire connector. I get how to test the purge solenoid with the 2 wire, but the vent solenoid with the 3 wire is throwing me. Any one knows what the 3rd wire does and will the vent solenoid throw the hated P0446 code?

As an aside, this is the only code in the system. Truck runs and starts good.

 

[RonD]

And whats the english definition you are using for P0446?

Always good to post what YOU think it is


Ford Trouble code list seen here: https://www.therangerstation.com/tech_library/OBD-II_codes.shtml

You should always look up codes on a FULL list, because the computer often has MANY codes it can use for each system
And in the case of EVAP system its ALOT of them, lol

P0440 Evaporative Emission Control System Malfunction
P0441 Evaporative Emission Control System Incorrect Purge Flow
P0442 Evaporative Emission Control System Leak Detected (small leak)
P0443 Evaporative Emission Control System Purge Control Valve Circuit
P0444 Evaporative Emission Control System Purge Control Valve Circuit
P0445 Evaporative Emission Control System Purge Control Valve Circuit Shorted
P0446 Evaporative Emission Control System Vent Control Circuit Malfunction
P0447 Evaporative Emission Control System Vent Control Circuit Open
P0448 Evaporative Emission Control System Vent Control Circuit Shorted
P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
P0450 Evaporative Emission Control System Pressure Sensor Malfunction
P0451 Evaporative Emission Control System Pressure Sensor Range/Performance
P0452 Evaporative Emission Control System Pressure Sensor Low Input
P0453 Evaporative Emission Control System Pressure Sensor High Input
P0454 Evaporative Emission Control System Pressure Sensor Intermittent
P0455 Evaporative Emission Control System Leak Detected (gross leak)


Computer picked P0446 Evaporative Emission Control System Vent Control Circuit Malfunction

So not a high or low pressure code, or a leak code

And it does include the word CIRCUIT, so electrical, but not a "circuit open or shorted" code, so probably not a broken wire or unplugged connector.
Also named Vent control circuit specifically

 

[mrmordun]

Wow, way to ask me the right question and provide me some information to make me think and apply logic myself.

The code reader I have says this exactly: P0446 $10 Generic
Evaporative Emission System Vent Control Circuit

Tells me its the vent valve or in the plumbing for it. Thanks.

Any Idea about why it has 3 wires. Im assuming 1 hot, 1 ground, the third is a signal wire of some sort?

 

[mrmordun]

Attaching a couple pictures to make sure I know what Im looking at. I think its the tank pressure sensor. If it is where the heck is the vent valve?

 

[mrmordun]

Finally found the vent solenoid, anyone want guess why I have a code?

Thanks RonD, you sent me down the right path with your question and information. Your awesome.

 

[sgtsandman]

Now to see if there is a pig tail available to repair the problem. Make sure you seal the splices well so the wires don't corrode at the repair. Heat shrink works the best. After soldering the wires, applying a little dielectric grease, then heat shrink is even better.

 

[mrmordun]

Found a pigtail, and paid dearly for it cause I cant really wait to fix it due to not wanting to gamble on better weather than today later down the road. The pigtail actually came with the little metal butt splices and heat shrink. That was not really a very comfortable place to work.

 

[RonD]

Good Work

But that really surprised me..................I would have expected P0447 Evaporative Emission Control System Vent Control Circuit Open

So I guess even computers screw up, I know my home PC does, lol..................stupid computer

 

[adsm08]

Good Work

But that really surprised me..................I would have expected P0447 Evaporative Emission Control System Vent Control Circuit Open

So I guess even computers screw up, I know my home PC does, lol..................stupid computer

To err is human.

To really eff things up you need a computer.

 

[RonD]

How true..................I used to just screw things up locally...................now I am an INTERNATIONAL screw up........stupid computer

 

[Dirtman]

I mean.... the computer wasn't really wrong at all, having the wires ripped out of the connector technically is a malfunction in the circuit.

It just wasn't overly specific about the precise nature of the malfunction. Whether its a transmission solenoid a vent solenoid or whatever I tend to see way more "generic circuit malfunction" codes than codes specifically stating short to ground or open circuit.

Maybe they just don't bother adding those more specific codes into the ECU? Maybe the scanner doesn't read them? Maybe once the ECU flags the generic malfunction code it doesn't bother throwing any others or testing for open/shorts? Maybe its a conspiracy?

 

[G8orFord]

Maybe the rat that chewed them also hacked the PCM to the more generic code so he'd have more getaway time.

 

[mrmordun]

Maybe they just don't bother adding those more specific codes into the ECU? Maybe the scanner doesn't read them? Maybe once the ECU flags the generic malfunction code it doesn't bother throwing any others or testing for open/shorts? Maybe its a conspiracy?

Could be my scanner is a Harbor Freight special?

Maybe the rat that chewed them also hacked the PCM to the more generic code so he'd have more getaway time.

Wasn't a rat. Pretty sure it was the tire shop that put my spare back up after a bought some new tires. Cant prove it though.

Thanks again RonD. That first post of yours really got my brain going down the right path.