P0446 EVAP Control System Vent Control Circuit Malfunction
 

Seasons Greetings All,

My service engine light is on and the tech at Quick Lube said this is the error code that is reporting. "P0446 EVAP Control System Vent Control Circuit Malfunction"

Any one know what this is, and the cost involved in fixing it? Is the car safe to drive?

Thanks,
Jon

Hi,
P0446="EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT" (Open or close malfunction in CCV - 2 trip detection logic).
Quote. "MONITOR DESCRIPTION. The ECM tests the Evaporative Emissions (EVAP) system using the fuel tank pressure sensor, Canister Close Valve (CCV), and EVAP VSV. The ECM closes the EVAP system and creates negative pressure (vacuum) into it. The ECM then monitors the internal pressure using the fuel tank pressure sensor..."
Toyota has TSB EG003-03* ("M.I.L. "ON" DTC P0441, P0442 AND/OR P0446") and TSB EG008-04R ("REPAIR MANUAL SUPPLEMENT... DTCP0446...") for RX330 a '04.
HTH,
-------------------------------------------
*"...The EVAP Purge VSV has been improved to correct the M.I.L. “ON” condition."
* Applicable Warranty: This repair is covered under the Lexus Comprehensive Warranty. This warranty is in effect for 48 months or 50,000 miles, whichever occurs first, from the vehicle’s
in-service date.

"Evaporative Emissions" are gasoline vapors coming from the fuel tank. Those are monitored and controlled by the EPA in addition to the exhaust emissions.

A very common cause of P0441, P0442, or P0446 is a missing, loose, or broken fuel cap. The system is that sensitive, so if the fuel cap isn't doing its job to control vapor emissions, the computer will flag it.

alflash mentioned two TSIB's for the 2004 RX 330.
The first, EG003-03, affects RX 330's made in Japan with serial numbers below 5367 (2WD) or 10665 (AWD). The solution is to replace a vacuum switching valve (VSV) which sticks and causes P0441, P0442, and/or P0446.

The second, EG008-04, doesn't talk about any quick fixes. Instead, it replaces the service manual's instructions for running a LEV II diagnostic test on the EVAP system.

If the fuel cap isn't the problem, then this should clealry be covered under the emissions warranty. If there is no other problem with the car, I don't think you need to rush to the dealer to get it fixed.

try tighting the gass cap. 99.9% of the time its that

Reply to PO446 code
 

No need to worry. If it's not your gas cap or loose/broken hose/fittings, then it the valve and/or charcoal canister. In my case, the valve failed, allowing fuel to enter the canister, rendering it unoperable. Since I live in NJ and my emissions inspection isn't until August, I'm going to continue driving my 1998 ES300 until late Spring/early Summer 2011. My mechanic said that it's ok to drive the car. It just won't pass emissions inspections (due in August). If there are no major problems with my car until then, I will then have it fixed. For a new valve and charcoal container plus installation, I was quoted $698. I have 160K miles on my car. It runs beautiful. Hey, things wear out. Lexus is expensive, but like I said, I'm driving a car that's going on 14 years old with 160K miles and I love the car. So what's $698 when compared to buying a newer model Lexus (I don't buy cars new) for $25K. Good luck.

Question could it be the VSV that's used for the Charcoal canister? I have a 1996 ES300? Also can you point out which one from the picture provided?

I do know that the bottom left is EGR emission. Which is the one I need to check?

My CEL came on over the weekend, took the car, 2002 RX300, in to Lexus dealer and on the ticket the service advisor told me $262.00 to repalce the VSV. The technician noted the "ENG EVAP CODES: VSV BROKEN AND RECOMMEND REPLACING. I asked the advisor what is the part and he told me he did not know. Anyone here know what is the part? and is it easy to replace yourself? Thanks in advance.
By the way the engine was replaced in March 2011 by Lexus at thier expense since it was an engine sludge problem.

http://lexus.sewellparts.com/oem-cat...X300-2003.html

Look at PNC: 17650G

Looks like there are two of them with different part numbers.

"PURPOSE
The vacuum switching valve for fuel pressure control is used to raise fuel pressure during hot restart conditions.

OPERATION
During a hot restart, the engine control module energizes the vacuum switching valve which redirects the vacuum supply for the fuel pressure regulator to the atmosphere. When the vacuum is vented, the fuel pressure regulator raises fuel pressure accordingly."

Took my 02 Lexus in for tune up and was told that I need a new Vent Valve Solenoid, its located on the back of the air filter housing, anyone know the part number, I been having a heck of a time looking for it anywhere and of course the dealer wont share part numbers as usual, but the mechanic did tell me local Toyota dealer had the part for about $85.00 and available by Wednesday if I ordered today. Thanks

Sorry to wake up an old thead.. good thread I ended up getting the dorman version.. problaby a no no but it's an old car 2002 RX300.. $40 bux.. if you don't hear back it measn it works.. issue I was having was everytime I filled up the car it would not start on the first try and took 4-5 cranks to start..

also this part is called so many different things, my mechanic called it a purge valve, others call it a vacuum switching valve
Dorman 911-612 Vacuum Switching Valve

My car has exact symptom as yours... after filling gas, I need second crank to start. I already check the VSV and it work fine... What's else are common failed items?

Update: I fixed the "not starting" issue after fueling. It's because the CCV is stuck open that allows vapor to clog the intake and make it hard to start. Luckily, the part is just stuck a little, so I energize it with 12V and blow it then it works again. The part is 90910-12149 or 90910-12201, I forgot to read it clearly.

Dts : P0001
 

my car wont start, checked with innova meter code : P0001 fuel volume regulator control circuit / open.
Location fuel regulator in 2004 RX330.

Thanks in advance

Can anyone explain where I can find the VSV for CCV? The pics above only locate the vsv for evap and I'm only getting the p0446 so maybe that would make sense.

And according to that chart there are 3 vsv solenoids? 1 by the intake, 1 by the canister and where is the third? My car won't allow. Me to fill it up and I always hear a suction noise when releasing the gas cap. I can also hear it gargle after putting gas into the tank as if something is blocking it. Any advice?

Charcoal canister
 

I haven't been able to pump gas normally in my 01 ES300 for at least 6 months now, Lexus said charcoal canister. It stops filling after about 5 seconds and I have to wait for the bubbles to settle and then I get another 3 seconds, annoying! Just today I got a CEL with P0446 but also P0300 misfire on 3 cylinders and a too lean code and a P0440. I think I'm at the point where I just have to do the whole canister. Any thoughts???...I was quoted $700 basically.