Engine-Codes - Toyota - P0446 TOYOTA

P0446 TOYOTA - EVAP System Vent Control Circuit

Repair Importance Level: 1/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P0446 TOYOTA Possible Causes

  • Missing Fuel cap
  • Incorrect fuel filler cap used
  • Fuel filler cap remains open or fails to close
  • Foreign matter caught in fuel filler cap
  • Vent control valve harness is open or shorted
  • Vent control valve circuit poor electrical connection
  • Faulty vent control valve

How is the P0446 TOYOTA code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Tech Notes

There are factory service bulletins for the following Toyota models:

Toyota RAV4
Toyota Tercel
Toyota Paseo
Toyota Camry
Toyota Avalon
Toyota Tacoma
Toyota 4Runner
Toyota T-100
Toyota Factory Service Bulletin OBDII Code P0446

2003 – 2004 Toyota Corolla
2003 – 2005 Toyota Matrix
Toyota Factory Service Bulletin OBDII Code P0446 Corolla and Matrix

If P0446 is combined with P0440 and P0441 use this bulletin:
2000-2003 Toyota Solara
2000-2003 Toyota Avalon
2000-2003 Toyota Camry
2001-2003 Toyota Sienna
Toyota Factory Service Bulletin OBDII Code P0446 Solara, Avalon, Camry, Sienna

2003-2004 Toyota 4Runner
2003-2004 Toyota Tundra
2004 Toyota Camry
2004 Toyota Sienna
2004 Toyota Highlander
2004 Toyota Solara
Toyota Factory Service Bulletin OBDII Code P0446

If only P0446 is present:
2001-2003 Toyota Sienna
Toyota Sienna Factory Service Bulletin OBDII Code P0446

Toyota P0441, P0446 EVAP Diagnostics and Vacuum Switching Valve Testing Video




User submitted video

What is the cost to diagnose the P0446 TOYOTA code

Labor: 1.0

The cost to diagnose the P0446 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

When is the code detected?

The P0446 codes triggered when an improper voltage signal is sent to Engine Control Module (ECM) through EVAP canister vent control valve.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Possible a noticeable fuel odor caused by the release of fuel vapors

P0446 TOYOTA Meaning

The Evaporative System (EVAP) canister vent control valve is located on the EVAP canister and is used to seal the canister vent.
This solenoid valve responds to signals from the Engine Control Module (ECM). When the ECM sends an ON signal, the coil in the solenoid valve is energized. A plunger will then move to seal the canister vent. The ability to seal the vent is necessary for the on board diagnosis of other evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains opened.

More Information

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