Subaru 2009 IMPREZA Service Manual page 740

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
5. DIAGNOSTIC METHOD
• Abnormality Judgement
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Judgement Value
Malfunction Criteria
Output voltage level
Front oxygen (A/F) sensor heater control
duty
Time Needed for Diagnosis: 4 ms × 500 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
• Normality Judgement
Judge as OK and clear the NG if the continuous time while the following conditions are established is more
than the predetermined time.
Judgement Value
Malfunction Criteria
Output voltage level
Time Needed for Diagnosis: Less than 1 second
Threshold Value
High
12.5 %
Threshold Value
Low
GD(H4SO)-16