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Home >> Subaru >> 2018 >> WRX STI >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (Diagnostics) (2 Of 4) (STI) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P0455: EVAP System (CPC) Leak Detected (Large Leak) >> Diagnostic Method >> Mode E (Measurement of reference pressure for judgment)
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Mode E (Measurement of reference pressure for judgment)

Judgment 1

Purpose: Judge the reference pressure stability.

Judge as NG when the following conditions are established.

Judgment 2

Purpose: Judge whether the reference pressure is within the normal range, and detect the vacuum pump and orifice malfunctions.

Judge the vacuum pump performance stability.

Judge as NG when the following conditions are established.

Judgment 3

Purpose: Judge the presence of evaporative emission system leak.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria Threshold Value DTC
Judgment 1
|Pressure sensor maximum output value - Pressure sensor minimum output value| > 314Pa (2.355mmHg, 0.1inHg) P2404
or
Judgment 2
Reference pressure for judgment < Value of Map 4
or
> Value of Map 5
P2404
or
Judgment 3
|Reference pressure for setting the target negative pressure - Reference pressure for judgment| > 941 Pa (136.4 mmHg, 277.9 inHg)
BAROMETRIC PRESSURE SPECIFICATION - MAP 4

Barometric pressure
(kPa (mmHg, inHg)
70 (525, 20.7) 80 (600, 23.6) 90 (675, 26.6) 100 (750, 29.5)
Reference pressure for judgment
(kPa (mmHg, inHg))
-4.5 (-34.02, -1.3) -4.6 (-34.815, -1.4) -4.7 (-35.618, -1.4) -4.9 (-36.42, -1.4)
BAROMETRIC PRESSURE SPECIFICATION - MAP 5

Barometric pressure
(kPa (mmHg, inHg))
70 (525, 20.7) 80 (600, 23.6) 90 (675, 26.6) 100 (750, 29.5)
Reference pressure for judgment
(kPa (mmHg, inHg))
-0.8 (-6.18, -0.2) -0.9 (-6.983, -0.3) -1 (-7.785, -0.3) -1.1 (-8.58, -0.3)

Time needed for diagnosis:  Approx. 24 min

At next engine start, confirm whether the enable conditions are satisfied even though refueling has been done during soaking, and determine the malfunction.

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