Subaru 2009 IMPREZA Service Manual page 787

Diagnostic Trouble Code (DTC) Detecting Criteria
AI: DTC P0140 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED
(BANK1 SENSOR2)
1. OUTLINE OF DIAGNOSIS
Detect the rear oxygen sensor open or short circuit. Judge as NG when the rear oxygen sensor voltage can
be determined to be abnormal considering conditions such as intake air amount, engine coolant tempera-
ture, main feedback control and deceleration fuel cut.
2. COMPONENT DESCRIPTION
(3)
V
(2)
(A) Electromotive force
(D) Lean
(1) Atmosphere
3. ENABLE CONDITION (USED ONLY FOR MALFUNCTION JUDGEMENT)
Secondary Parameters
Closed loop control at the rear oxygen
sensor
Target output voltage of rear oxygen sen-
sor
Amount of intake air
Engine coolant temperature
Misfire detection every 200 rotations
Front oxygen (A/F) sensor compensation
coefficient
Battery voltage
Deceleration fuel cut of 6000 ms or
more.
4. GENERAL DRIVING CYCLE
Perform the diagnosis once after starting the engine.
(1)
(2)
(B) Air fuel ratio
(E) Theoretical air fuel ratio
(2) Exhaust gas
Enable Condition
In operation
0.55 V + 0.05 V
10 g/s (0.35 oz/s)
75 °C (167 °F)
< 5 time(s)
Not in limit value
10.9 V
Experienced
GD(H4SO)-63
GENERAL DESCRIPTION
(E)
(A)
(C) (B)
(C) Rich
(F) Comparative voltage
(3) Electromotive force
(F)
(D)
EN-01696