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OBD0229
N: DTC P0139
—REAR OXYGEN SENSOR CIRCUIT SLOW
RESPONSE (RO2
—R)—
DTC DETECTING CONDITION:
Two consecutive trips with fault
10N1Check DTC P0136 on display.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
WIRING DIAGRAM:
LHD Model
B2M0760
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WIRING DIAGRAM:
RHD Model
B2M0789
10N1
CHECK DTC P0136 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0136?
: Inspect DTC P0136 using“10. Diagnostics Chart
with Trouble Code 2-7 [T1000]”.
NOTE:
In this case, it is not necessary to inspect DTC P0139.
: Replace rear oxygen sensor.
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OBD0232
O: DTC P0141
—REAR OXYGEN SENSOR HEATER
CIRCUIT MALFUNCTION (RO2H)—
DTC DETECTING CONDITION:
Two consecutive trips with fault
10O1Check DTC P0135 on display.
10O2Connect Subaru Select Monitor or the OBD-II
general scan tool, and read data.
10O3Check output signal from ECM. (Using voltage
meter.)
10O4Check power supply to rear oxygen sensor.
10O5Check rear oxygen sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
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WIRING DIAGRAM:
LHD Model
B2M0761
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WIRING DIAGRAM:
RHD Model
B2M0790
10O1
CHECK DTC P0135 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0141 and
P0135 at the same time?
: Go to next step 1).
: Go to step10O2.
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B2M0553A
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between ECM connec-
tor and chassis ground.
: Connector & terminal
(B84) No. 42—Chassis ground:
Is the resistance less than 5Ω?
: Repair poor contact in ECM connector.
: Repair harness and connector.
NOTE:
In this case, repair the following:
Open circuit in harness between ECM and coupling con-
nector (B22)
Open circuit in harness between coupling connector
(B22) and engine grounding terminal
Poor contact in rear oxygen sensor connector
Poor contact in rear oxygen sensor connecting harness
connector (B19)
Poor contact in coupling connector (B22)
OBD0145A
10O2CONNECT SUBARU SELECT MONITOR
OR THE OBD-II GENERAL SCAN TOOL,
AND READ DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
3) Turn ignition switch to ON and Subaru Select Monitor or
OBD-II general scan tool switch to ON.
4) Start engine.
B2M0498
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F33
F33: Rear oxygen sensor heater current is indicated.
: Is the value more than 0.2 A in function
mode F33?
: Repair connector.
NOTE:
In this case, repair the following:
Poor contact in rear oxygen sensor connector
Poor contact in rear oxygen sensor connecting harness
connector
Poor contact in ECM connector
: Go to step10O3.
OBD-II scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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B2M0554A
10O3CHECK OUTPUT SIGNAL FROM ECM.
(USING VOLTAGE METER.)
1) Start and idle the engine.
2) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 37 (+)—Chassis ground ( ):
Is the voltage less than 1.0 V?
: Go to step10O4.
: Go to next.
: Does the voltage change less than 1.0 V by
shaking harness and connector of ECM
while monitoring the value with voltage
meter?
: Repair poor contact in ECM connector.
: Go to next step 3).
B2M0554A
3) Disconnect connector from rear oxygen sensor.
4) Measure voltage between ECM connector and chassis
ground.
: Connector & terminal
(B84) No. 37 (+)—Chassis ground ( ):
Is the voltage less than 1.0 V?
: Replace ECM.
: Repair short circuit in harness between ECM and
rear oxygen sensor connector. After repair short
circuit in harness, replace ECM.
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OBD0710C
10O4CHECK POWER SUPPLY TO REAR OXY-
GEN SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from rear oxygen sensor.
3) Turn ignition switch to ON.
4) Measure voltage between rear oxygen sensor connec-
tor and engine ground or chassis ground.
: Connector & terminal
2200 cc California model
(B19) No. 2 (+)—Engine ground ( ):
Except 2200 cc California model
(T6) No. 2 (+)—Chassis ground ( ):
Is the voltage more than 10 V?
: Go to step10O5.
: Repair power supply line.
NOTE:
In this case, repair the following:
Open circuit in harness between main relay and rear
oxygen sensor connector
Poor contact in rear oxygen sensor connector
Poor contact in rear oxygen sensor connecting harness
connector (Except 2200 cc California model)
OBD0706
10O5
CHECK REAR OXYGEN SENSOR.
1) Turn ignition switch to OFF.
2) Measure resistance between rear oxygen sensor con-
nector terminals.
: Terminals
No. 1—No. 2:
Is the resistance less than 30Ω?
: Repair harness and connector.
NOTE:
In this case, repair the following:
Open circuit in harness between rear oxygen sensor and
ECM connector
Poor contact in rear oxygen sensor connector
Poor contact in ECM connector
Poor contact in rear oxygen sensor connecting harness
connector
: Replace rear oxygen sensor.
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