2001 TOYOTA CAMRY 2.2L 4-cyl P0446 EVAP test failure [California] 110,000 miles

How can I isolate failed component? P0446 says Vent Control circuit failure. Most people indicate the VSV at the charcoal canister (at the gas tank) is the problem. Toyota calls this the Vapor Pressure Sensor VSV, is this the same as Vent Control circuit/VSV? The other EVAP VSV is located under the hood, is this the Purge valve? Info says the P0446 code is generated in Stage 5 of EVAP test, from checking the Bypass VSV. Which of the above is Bypass VSV? How do I test the VSV's to find which one is bad? Where is the vapor pressure sensor, and how do I test it? How do I test the charcoal canister? I read it can be carefully cleaned with air hose (compressor), how do I do this?

I read Toyota has had long term problem with P0446 and issued service bulletin, what is this fix?

I read some people replaced charcoal canister, both VSV's and sensors and still didn't fix code. In the past I have sometimes gotten P0446 when fuel is very low in tank, usually Arco gas, and the weather is very hot; but it cleared when tank was filled up. Finally, it takes about 10 drive cycles for the Monitor to complete; is there any way to verify fix/failure immediately without waiting??

Thanks for your help.

Answer:

Fault Code P0446 - EVAP(Evaporative Emission System) purge/vent solenoid circuit condition. Your Toyota Camry EVAP system has a pressure sensor to detect if the tank remains pressurized while the EVAP monitor is running, basically ensuring it is not leaking. If the tank depressurizes during the EVAP test, a trouble code(s) is set indicating a vapor leak and/or a defective EVAP system component(s).

Probable Causes:
1.) Purge or vent solenoids defective
2.)Check connector and wiring
3.)Fuel saturated vapor canister
4.)Failed EVAP vent solenoid

Initially check all hoses to the charcoal canister and VSV systems. Your Toyota's charcoal canister could have a leak, defective VSV for pressure sensor or vapor pressure sensor. Purchase a new Charcoal Canister. It will be equipped with a new Pressure Sensor and Vent Valve.

posted by SmogTips Support