Subaru IMPREZA GD 2007 Series Manual page 1930

asieps_tobira_IM_US.book 139 ページ ２０１２年１月１７日 火曜日 午後３時４８分
Diagnostic Trouble Code (DTC) Detecting Criteria
5. DIAGNOSTIC METHOD
Purge control solenoid valve stuck open fault diagnosis
DTC
P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)
Purpose of Mode Z
When performing the leakage diagnosis of EVAP system, the purge control solenoid valve must operate nor-
mally. Therefore, mode Z is used to diagnose the purge control solenoid valve stuck open condition.
Note that if a purge control solenoid valve stuck open fault is detected, the EVAP system leakage diagnosis
is cancelled.
Purge Control Solenoid Valve Function Diagnosis [P0457]
Purge control solenoid valve functional diagnosis is performed by monitoring the tank pressure in mode Z.
Normality Judgment
Judge as OK and change to Mode A when the criteria below are completed in 3 seconds after Mode Z started.
Judgment Value
Malfunction Criteria
(Tank pressure when Mode Z started) –
(Tank pressure when Mode Z finished)
Normal
(1) Mode Z
(2) 3 seconds
• evptez – evptezha ≤ 0.4 kPa (3.0 mmHg, 0.12 inHg)
• evptezini – evptezha ≤ 0.4 kPa (3.0 mmHg, 0.12 inHg)
Normal when both above are established
Abnormality Judgment
If OK judgment cannot be made, extend Mode Z 16 seconds more, and Judge as NG when the malfunction
criteria below are met.
Judgment Value
Malfunction Criteria
(Tank pressure when Mode Z started) –
(Tank pressure when Mode Z finished)
Tank pressure when Mode Z started
Time of 2 2 or more fuel no sloshing
Threshold Value
≤ 0.4 kPa (3.0 mmHg,
0.12 inHg)
(1)
(2)
evptez
evptezini
(3)
0
(4)
(3) Fuel tank pressure
(4) 0.4 kPa (3.0 mmHg, 0.12 inHg)
Threshold Value
> 0.6 kPa (4.5 mmHg,
0.18 inHg)
≤ 1.43 kPa (10.7
mmHg, 0.42 inHg)
≥ 40 seconds
GD(H4DOTC)-139
GENERAL DESCRIPTION
DTC
P0457
evptezha
(5)
(5) OK judgment
DTC
P0457
EN-02869