Subaru 2009 IMPREZA Service Manual page 1674

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
720° Interval Difference Method
Diagnostic domg 720 = (omg 1 – omg 0) – (omg 5 – omg 4)
value
Misfire domg 720 > Judgement value
judgement
domg720
domg720
• FTP 1.5 times misfire (Misfire occurrence level which influences exhaust gas)
• Abnormality Judgement
Judgement Value (Judge that malfunction occurs when the misfire ratio is high in 1000 engine revs.)
Malfunction Criteria
FTP emission judgement value
Time Needed for Diagnosis: 1000 engine revs.
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
• Normality Judgement
Judgement Value
Malfunction Criteria
FTP emission judgement value
Time Needed for Diagnosis: 1000 engine revs.
Judge as misfire
Threshold Value
20 × 100/2000% in 1000 revs.
(except for WRX-SS model)
18 × 100/2000% in 1000 revs.
(WRX-SS model)
Threshold Value
< 20 × 100/2000% in 1000 revs.
(except for WRX-SS model)
< 18 × 100/2000% in 1000 revs.
(WRX-SS model)
GD(H4DOTC)-86
Threshold valve
Judged as misfire.
EN-03274