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99 Camry I4 MIL ON P0446

06-25-2004, 08:45 PM
Hi, there,

I have a 99 Camry 4D, I4, with 74K miles. About a month ago, the MIL lighted up. Went to a AutoZone; the code read out is P0446.

I have since put a new gas cap(bought at a Toyota dealer), pulled the IEC(ICE) fuse. The check-engine light keeps coming back.

It's my understanding that P0446 is related to the fuel fume recovery system. To be more specific, EVAP Vent Control Circuit Malfunction.

My question here is that:

1. Will it harm the car whendriving with the P0446 on?

2. Apart from replacing the Charcoal Canistor, it it possible of other causes?

Thanks inadvance!


06-26-2004, 02:38 PM
I have seen hundreds of P0446 codes on Camry like yours. 90% of the time it is caused by a bad tank by-pass valve (VSV) on the charcoal canister. You can check the valve by removing it and applying power to one pin and ground to the other. The valve should click... you'll hear it and feel it. Sometimes the valve sticks intermittently, and you may not experience it when testing it.
The P0446 can also be caused by a bad Canister Control Valve located on the air filter housing. You can test it the same way. This valve turns on and kind of clicks rapidly when power and ground are applied.
There can also be a leak in the evaporative system. This is very difficult to find, and you'd need special equiptment to test for a leak. Your best bet is the dealer. They see the P0446 everyday, and they'll be able to diagnose the problem relatively easily. Usually they charge 1 hour labor to diagnose it. From there you can repair it yourself if you want.
The EGR valve will NOT cause the P0446 code. The EGR system have a few codes specific to it, like P0401.
Your problem is in the Evap. Emission System.

06-26-2004, 07:12 PM
Thank you, Erndog1369.

I have heard that overfill of gas will cause bad canister; and the check engine light came on after about of one week after I accidently overfilled gas(the auto shut off did not work).

So the fault is narrowed to valves around the charcoal canister.

I will let a dealer check it out, due to the location of the canister.

BTW, will it harm other systems on the car?

Thanks again!

03-13-2007, 12:08 PM
Where is the charcoal canister located? How easy is it to replace?

03-13-2007, 12:30 PM
Where is the charcoal canister located? How easy is it to replace?

check the manual stickied at the top of the forum. If I remember right, the can is just forward of the gas tank in the rear of the car. There are a few things that might stop you from replacing it, but I think it is possible if you have a good amount of patience and time. I don't know what year your car is, but there is a warranty extension notice posted at the top of the forum for this system on certain years.

ty1, you are barely missing out on this warranty. I would still contact toyota and ask if they want to be generous. They replaced it for free in my 98, your car isn't too different, though obviously some differences made them not include 99 in the warranty. Maybe if enough people with 99s call in they will expand the warranty??

07-11-2007, 10:15 AM
ughh I am having same problem..Dealership wants 90 for diaganostic test.. Is it really worth that much?

Soilent Green
07-12-2007, 06:01 PM
I got the VSV for like 90$ CDN, so if their diagnosis is worth the same price than the VSV, I say lift the car and carefully check all the hoses FROM and TO the canister, then if you don't find anything, buy the part and do it yourself.

I actually got a brand new VSV that I need to install to get rid of P0446, but I started body restoration on my '98 and realized I had to finish it up before going with the vsv.

I will post a D.I.Y. on how to change the VSV yourself when I do it, probably next week.

07-13-2007, 11:25 AM
Item Number 7774006093 internet price $193.46 - Vapor canister All - 2.2 liter 1998 - 1999.
This comes with the VSV.

07-13-2007, 04:15 PM
thanks let me know

08-12-2007, 02:27 PM
What would be the consequences of not replacing the VSV? Would there be any damage to the converter or 02 sensors?

08-12-2007, 03:23 PM
not sure what "could" happen, but I drove it for over a year with the problem, no new problems cuz of it.

08-14-2007, 08:45 AM
Had the check engine light come on this weekend on my 2002 Camry with V6 engine. Code P0446. Replaced gas cap and reset the code. Everything is fine so far. My dealer wanted $107 just to read the codes. So I went to Auto Zone which did the service at no charge. Down side to Auto Zone is the counter help thought it was the EGR valve. I just said thanks and went home to check this forum for help.

Update: The gas cap replacement kept the check engine light off for two weeks. Got a PO446 code again so this time I replaced the Charcoal canister unit. They ain't cheap from Toyota either.

10-01-2007, 04:02 PM
Where is vsv in a 99 camry?

Soilent Green
10-22-2007, 09:37 AM
Should be at the back, near the gas tank. They are located there since '98

06-18-2008, 01:27 PM
Thank you very much Sir.
Under your guidance by pdf pictures and repair notes,I clean EGR Valve and EGR modules and conneted all tubings.since last 2 days code po401 is gone.Now i am only getting two codes po441 and Po446. Now what is suggestions,that a quite new person like me can do with minimum money matters,please.
Do I need to clean or replace VSV switch or valve.Do I need to clean or replace charcoil canister by new or used??
Where is charcoial canister located??Is it a big drum on back bottom of Camry2000???

07-20-2010, 04:53 PM
I have a 1999 toyota camry. The trouble codes listed were PO401 & PO446. I tested the SVS for EVAP all ok. I tested VSV for Pressure sensor. VSV was ok but I found 11.90 volts coming into it. So I traced the wiring up through to the PCM. (I had the same reading to there) I unplugged from the PMC and tested the output pin and it too had an 11.90 volt reading. My question is, is there anything that will cause the PCM to send that much voltage through that circuit other than having a PCM malfunction? I did not test anything for PO401 circuit. Thank you very much for any help I might recieve

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