hcfarm

trying to track down P0446 code, is there any info on How to check Vacuum Switching Valve for the charcoal canister?

Is there a way to clean out the canister? Are there any other switches or sensors I can check with digital volt meter?

thanks
jon

Lexmex

I've gone over the possibilities of this code in the past.

However, it'd actually be very complicated for me to explain. This is actually one of the few repairs I recommend getting the service manual if you want to DIY, because it could involve any number of possibilities including the charcoal canister. In fact, in volume 1 of the service manual, the entire procedure to check this code runs almost 10 pages. Most people who I know have gotten this code have wound up going to Lexus and having the charcoal canister replaced.

hcfarm

thanks lexmex,
this looks like a very common code problem in alot of forums that I have visited, even the toyota forums talk of it..looks like an expensive fix thru lexus...what would be the best option to purchase a new canister as a unit?

I looked at it this morning like you said for cracks, hose connection, electrical connectors, it doesn't really look like much to go wrong on the outside. all the items i mentioned looked in decent shape, all the rubber looked good..

where is the best place to purchase the manual? I have rebuilt motors from the workshop manuals, but that was when I was a teenager, alot has changed since then, been about 30 years, this is the first vehicle I have actually had that had this problem, but I bought it used, so I have a few things to repair and maintain....

I have a chilton manual, but it is very lacking in descriptive detailing..you are talking workshop manual from lexus...right?

thanks for your help, I would probably like to get a lexus manual later if not outrageous pricing

jon

Lexmex

I can't really say whether to go out an purchase this canister. As I remember somewhere, they ain't cheap.

The dealers do sell these manuals (that's where I ordered mine from) and I know they are expensive (about $200 USD), but they are worth every penny, especially volume 1 which contains all the OBD2 error codes. I think they also sold these on CD for cheaper, both volumes.

hcfarm

no, I won't go out and purchase a canister...not yet, but i am interested in the manual..will look into the cd option too..