Subaru 2009 IMPREZA, Service Manual

Page: 1700 / 3619

GD(H4DOTC)-112
Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
3. ENABLE CONDITIONS
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 (
6
|(sglmd
n
– sglmd
n–1
)|) and rear oxygen sensor output voltage devia-
tion cumulative value (
6
|(ro2sad
n
– ro2sad
n–1
)|), and when the front oxygen (A/F) sensor lambda deviation
cumulative value (
6
|(sglmd
n
– sglmd
n–1
)|) becomes the predetermined value or more, calculate the diag-
nostic value.
• Abnormality Judgement
If the duration of time while the following conditions are met is within the time indicated, judge as NG.
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.
Time Needed for Diagnosis: 30 — 55 seconds
Secondary Parameters Enable Conditions
Battery voltage
t
10.9 V
Atmospheric pressure
t
75 kPa (563 mmHg, 22.2 inHg)
Engine coolant temperature
t
70 °C (158 °F)
Estimated catalyst temperature
t
460 °C (860 °F)
Misfire detection every 200 rotations < 5 time(s)
Learning value of evaporation gas density < 0.2
Sub feedback In operation
Evaporative system diagnosis Not in operation
Time of difference (< 0.10) between actual
lambda and target lambda
t
1000 ms
Vehicle speed > 60 km/h (37.3 MPH)
Amount of intake air
t
10 g/s (0.35 oz/s)
and
< 50 g/s (1.76 oz/s)
Engine load change every 0.5 engine revs. < 0.02 g/rev (0 oz/rev)
Rear oxygen output change from 660 mV or
less to 660 mV or more Experienced after fuel cut
Elapsed time after starting the engine
t
200 s (except for WRX-SS model)
t
234 s (WRX-SS model)
Purge execution calculated time
t
5 s
Judgement Value
Malfunction Criteria Threshold Value
6
|(ro2sad
n
– ro2sad
n–1
)| /
6
|(sglmd
n
– sglmd
n–1
)| > 11 (except for WRX-SS model)
> 8.2 (WRX-SS model)
Judgement Value
Malfunction Criteria Threshold Value
6
|(ro2sad
n
– ro2sad
n–1
)| /
6
|(sglmd
n
– sglmd
n–1
)|
d
11 (except for WRX-SS model)
d
8.2 (WRX-SS model)