P0446 EVAP Control System Vent Control Circuit Malfunction

[StreetLexus]

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

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[alflash]

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.

[rxdriver]

"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.

[koolaidman]

Originally Posted by StreetLexus

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

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

[oneillmw]

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.

[VicsIS350]

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?

[GlennB]

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.

[RX330inFL]

Originally Posted by GlennB

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."

[GlennB]

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