Subaru 2009 IMPREZA Service Manual page 1700

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
Secondary Parameters
Battery voltage
Atmospheric pressure
Engine coolant temperature
Estimated catalyst temperature
Misfire detection every 200 rotations
Learning value of evaporation gas density
Sub feedback
Evaporative system diagnosis
Time of difference (< 0.10) between actual
lambda and target lambda
Vehicle speed
Amount of intake air
Engine load change every 0.5 engine revs.
Rear oxygen output change from 660 mV or
less to 660 mV or more
Elapsed time after starting the engine
Purge execution calculated time
4. GENERAL DRIVING CYCLE
Perform the diagnosis only once at a constant 60 km/h (37.3 MPH) or higher.
5. DIAGNOSTIC METHOD
After establishing the execution conditions, calculate the front oxygen (A/F) sensor lambda deviation cumu-
lative value per 32 milliseconds × 4 ( |(sglmd
tion cumulative value ( |(ro2sad
cumulative value ( |(sglmd
nostic value.
• Abnormality Judgement
If the duration of time while the following conditions are met is within the time indicated, judge as NG.
Judgement Value
Malfunction Criteria
|(ro2sad – ro2sad )| /
n n–1
Time Needed for Diagnosis: 30 — 55 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
• Normality Judgement
Judge as OK and clear the NG if the continuous time while the following conditions are established is within
the predetermined time.
Judgement Value
Malfunction Criteria
|(ro2sad – ro2sad )| /
n n–1
Time Needed for Diagnosis: 30 — 55 seconds
10.9 V
75 kPa (563 mmHg, 22.2 inHg)
70 °C (158 °F)
460 °C (860 °F)
< 5 time(s)
< 0.2
In operation
Not in operation
1000 ms
> 60 km/h (37.3 MPH)
10 g/s (0.35 oz/s)
and
< 50 g/s (1.76 oz/s)
< 0.02 g/rev (0 oz/rev)
Experienced after fuel cut
200 s (except for WRX-SS model)
234 s (WRX-SS model)
5 s
– ro2sad )|), and when the front oxygen (A/F) sensor lambda deviation
n n–1
– sglmd )|) becomes the predetermined value or more, calculate the diag-
n n–1
|(sglmd – sglmd )| > 11 (except for WRX-SS model)
n n–1
> 8.2 (WRX-SS model)
|(sglmd – sglmd )| 11 (except for WRX-SS model)
n n–1
8.2 (WRX-SS model)
GD(H4DOTC)-112
Enable Conditions
– sglmd )|) and rear oxygen sensor output voltage devia-
n n–1
Threshold Value
Threshold Value