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Thursday, January 28, 2016

P0441 1997 TOYOTA CAMRY - Evaporative Emission Control System Incorrect Purge Flow

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
- Incorrect fuel tank vacuum relief valve

Tech notes

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





When is the code detected?

Pressure in charcoal canister and fuel tank does not drop during purge control (2 trip detection logic)

Possible symptoms

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

P0441 1997 Toyota Camry Description
The Engine Control Module (ECM) tests the Evaporative Emission (EVAP) system for the following conditions:
- Large and small leaks
- Excess vacuum
- Purge flow during non-commanded conditions
- Fuel Level and Fuel Pressure sensor faults
- EVAP Purge and Vent Valve faults
The ECM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. The ECM commands both the EVAP Purge Solenoid and the EVAP Vent Valve ON when the conditions are met in order to apply an engine vacuum to the EVAP system. The ECM commands the EVAP Purge Solenoid OFF once the system has reached a predetermined level of vacuum. This test verifies if a vacuum can be achieved in the EVAP system. Failure to develop a vacuum may be caused by a large leak or a restriction.

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