Where is the Voltage Solenoid Valve?

[Traderjoe]

Hello all,
I just got a check engine code of P0446. I checked the internet and it points to either the gas cap loose, or a faulty voltage solenoid valve. I tightened the gas cap, cleared the codes, but it came back. So I guess its a faulty voltage solenoid valve.

But where is it?! Is it a DIY job?

Pleaes advise.

[Downhillzze110]

Originally Posted by Traderjoe

Hello all,
I just got a check engine code of P0446. I checked the internet and it points to either the gas cap loose, or a faulty voltage solenoid valve. I tightened the gas cap, cleared the codes, but it came back. So I guess its a faulty voltage solenoid valve.

But where is it?! Is it a DIY job?

Pleaes advise.

are you referring to the the Evap VSV, aka Vacuum Switching Valve? it is an easy DIY if its the underhood VSV. bad news is, it ain't cheap. a new VSV is $170 from toyota, and only toyota has them new. i'd get a repair manual and look up the trouble-shoot for p0446.

[fishexpo101]

There is also a VSV on the vapor canister itself - not hard to replace, cost can vary - generally run from $70+ for that valve. Before you start swapping parts, you'll need to find the root cause of the P0446. For some, it is the VSV, in my case - it was the tank cut-off valve. Only way to know for sure is to get the EVAP system smoke tested for leaks.

[Downhillzze110]

P0446 means, for the 8th gen corolla with or without VVT-i, and i quote directly from the Haynes manual: EVAP canister vent control valve circuit fault.
now: my question is are you also getting any of these codes: P0440, P0441, P0442, P0450, or P0451?
if not then you need to get your car on lifts and check your vent valve's wiring and voltage levels. if any of this went over your head than take your car to a quality tech shop.

[Traderjoe]

Originally Posted by Downhillzze110

P0446 means, for the 8th gen corolla with or without VVT-i, and i quote directly from the Haynes manual: EVAP canister vent control valve circuit fault.
now: my question is are you also getting any of these codes: P0440, P0441, P0442, P0450, or P0451?
if not then you need to get your car on lifts and check your vent valve's wiring and voltage levels. if any of this went over your head than take your car to a quality tech shop.

Nope, all I get is a P0446. Two of them actually. Checking wiring or voltage levels is not a problem. I can do that. I just need to know where to look and what to look for. How do I test the voltage levels?

I have a Haynes manual for this car too. But I don't see anything about a vent valve, or a vacuum solenoid valve.

[Traderjoe]

Originally Posted by fishexpo101

There is also a VSV on the vapor canister itself - not hard to replace, cost can vary - generally run from $70+ for that valve. Before you start swapping parts, you'll need to find the root cause of the P0446. For some, it is the VSV, in my case - it was the tank cut-off valve. Only way to know for sure is to get the EVAP system smoke tested for leaks.

Vapor Canister? Is that the same as the charcoal canister?

[Downhillzze110]

you said you have a haynes manual? the troubleshooting for the evap system starts on page 6-21 to 6-22. sections 13-23. i know alldata has a Factory service bulletin about some 8th gens throwing ghost p0446 codes due to faulty ECUs. you may want to look into that considering how you have THAT code and no others. which is highly irregular.
side note. i drive a car thats throwing p0441 and p0446, and i have no idea why.

[Traderjoe]

Originally Posted by Downhillzze110

you said you have a haynes manual? the troubleshooting for the evap system starts on page 6-21 to 6-22. sections 13-23. i know alldata has a Factory service bulletin about some 8th gens throwing ghost p0446 codes due to faulty ECUs. you may want to look into that considering how you have THAT code and no others. which is highly irregular.
side note. i drive a car thats throwing p0441 and p0446, and i have no idea why.

Thanks for the heads up. How do you suggest I go about then? alldata seems to be a member only site. Take it to the stealership? They'll probably just replace something and charge me a fortune.

Not sure if it helps, but the car has about 120K on it.

[Downhillzze110]

i'd follow the troubleshoot in the manual and only take it somewhere after you've exhausted all other possibilities. i'm about to take mine to the dealership because even my emmisions control teacher and i couldn't quite pinpoint where my codes are coming from.. although we think its either a bad fuel tank pressure sensor or a faulty canister vent valve. you honestly just might have a loose connection or a bad wire, and yes, something that small and stupid could throw that code.
Believe me, if a brand new spark plug wire leaning against a aluminum strut tower bar can throw a cylinder 4 misfire than a bad connection can throw an evap code.