Hi all,

My engine light has been on for a while and today I used a wifi odb dongle ran diag and it gave me a code "P0446 - Evaporative Emission System Vent Control Circuit",

After calling couple shops they suspect its the evap cannister vent valve.


1) is that the samething as Vacuum Switching Valve (VSV) ?

2) I would like to do it myself and wonder if any of you have instructions that could help me on this?



Thanks all!

 

Search the P0466 code and gas cap

 

p0446 with no other code is a closed CCV in other words canister closed valve is clogged per factory service manual.

and for your information VSV ie. Vacuum switching valve is on the driver side next to the intake manifold on GS400, id have too look at a diagram to find gs300 vsv. The CCV is the valve off of the charcoal canister in the rear of the vehicle i believe, never looked at my charcoal canister so don't know to be exact.

 

Only because I've posted it a ton of times am I able to post it again. Yea the valve is on the canister, its available here (log in to sewell with your Club Lexus screen name and get a $25 discount):

http://lexus.sewellparts.com/oem-cat...S300-2000.html

Its #77740N on the below picture on the top right.




Also available on ebay for $28 bucks:

http://www.ebay.com/itm/Vacuum-Switching-Valve-Dorman-911-602-/271721458387?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f43dc6ad3&vxp=mtr

 

That's great information!! thanks guys i'm going to try to replace it soon and see if it fix. i'll report back.

 

...........

 

Assume you have the same problem and wonder what the resolution was? If so a nice way of bumping might be to do something like this (although the OP hasn’t been on since 2019):

@femin following up from your post above, did you get a resolution? Thanks

 

Depending on how many miles the car has, more likely the Evap Cannister is full. The solenoid is far less likely to fail.

The Evap Cannister sits on top of the gas tank, difficult to access and replace. It may save time and money to buy the whole canister assembly with the VSV and swap it in. New canister from dealer may be $600.-800; an used one may be $100 -200..

 

I had a kinked purge line behind the intake manifold by the firewall drivers side, check that line and follow it where it goes down from the valves

 

Anyone ever remove the canister or replaced the valve while the canister is still bolted on?
Nothing on YouTube I could find regarding the removal of this unit

 

To remove the canister, jack the rear up, remove RR passenger wheel. 2 bolts hold the bracket at the canister's rear end to the frame.

Also remove the bracket from the canister to wiggle it out..

 

Is it possible to replace the VSV without removing the axel,gas tank etc?
I have smaller hands if that helps me out 😂

 

VSV is accessible by removing the rear driver side wheel.

It's screwed into a bracket on top of the canister with 1 small philips screw. Use a short screw driver to take out then disconnect the connector.

But are you sure the VSV caused the P0446 code? It's more likely a fine leak from the overflow valve on top of the gas tank. To avoid wasting lots of time and money, have a guy with a scan tool that can turn on and off those valves and check for leaks. Lexus dealers charge about $100 for diagnostics with credit towards repairs. Smoke test can not find fine leaks.