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Home >> Subaru >> 2018 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (2 Of 4) (STI) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P0441: EVAP System (CPC) Incorrect Purge Flow >> Diagnostic Method
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Diagnostic Method

Close the Evaporative Leak Check Module switching valve, and close the fuel tank completely, and perform the forced purging. If pressure change amount is -0.7kPa (-5mmHg, -0.2inHg) or less, judge as malfunction of purge flow.

Except for TYPE RA 

G12456818Courtesy of SUBARU OF AMERICA, INC.

*The purge gas is calculated from the Manifold Absolute Pressure (MAP) and Commanded purge control duty ratio.

Judge as NG when the following conditions are established.

TYPE RA 

G12456819Courtesy of SUBARU OF AMERICA, INC.

*1: The purge gas is calculated from the Manifold Absolute Pressure (MAP) and Commanded purge control duty ratio.

*2: The generated evaporative gas is the value calibrated under the high temperature in which the largest amount of evaporative gas is generated.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION (EXCEPT FOR TYPE RA)

Malfunction Criteria Threshold Value
Evaporative Leak Check Module pressure (gauge) > -0.7kPa (-5mmHg, -0.2inHg)
Integrated purge gas amount ≥ 10.56g (0.37oz)*

* It is approximately 2 sec per the integration of purge to reach 1g at vehicle speed of 40 MPH.

JUDGMENT VALUE SPECIFICATION (TYPE RA)

Malfunction Criteria Threshold Value
Evaporative system leak check module pressure (gauge) > -0.4kPa (-3mmHg, -0.1inHg)
Sum value (purge gas - generated evaporating gas) ≥ 3g (0.11oz)*

* It is approximately 2 sec per the integration of purge to reach 1g at vehicle speed of 40 MPH.

Time needed for diagnosis:  Less than 1 second

Malfunction indicator light illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.