Page 1272 of 2453

EN(H6DO)(diag)-111
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
2CHECK FRONT OXYGEN (A/F) SENSOR
HEATER CURRENT.
1) Turn the ignition switch to OFF.
2) Repair the battery short circuit of harness
between ECM and front oxygen (A/F) sensor
connector.
3) Turn the ignition switch to ON.
4) Read the data of front oxygen (A/F) sensor
heater current using Subaru Select Monitor or
general scan tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 2.3 A? Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
END.
3CHECK OUTPUT SIGNAL OF ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 6 (+) — Chassis ground (–):
(B135) No. 7 (+) — Chassis ground (–):
Does the voltage change by
shaking the ECM harness and
connector?
Repair the battery
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
END.
Step Check Yes No
Page 1273 of 2453
EN(H6DO)(diag)-112
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
O: DTC P0057 HO2S HEATER CONTROL CIRCUIT LOW (BANK 2 SENSOR 2)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
LOW (BANK 2 SENSOR 2), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
Page 1275 of 2453

EN(H6DO)(diag)-114
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK POWER SUPPLY TO REAR OXY-
GEN SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from rear oxygen
sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between rear oxygen
sensor connector and chassis ground.
Connector & terminal
(E25) No. 2 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 2.Repair the power
supply line.
NOTE:
In this case, repair
the following item:
•Open circuit
of harness be-
tween main re-
lay and rear
oxygen sensor
connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
of coupling con-
nector
2CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B134) No. 3 — Chassis ground:
(B134) No. 5 — Chassis ground:
(B137) No. 1 — Chassis ground:
(B137) No. 2 — Chassis ground:
(B137) No. 3 — Chassis ground:
(B137) No. 7 — Chassis ground:
Is the resistance less than 5
Ω?
Go to step 3.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
engine ground
terminal
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
3CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of rear oxygen sensor heater
current using Subaru Select Monitor or general
scan tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 0.2 A? Repair the con-
nector.
NOTE:In this case, repair
the following item:
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
of coupling con-
nector
•Poor contact
in ECM connec-
tor
Go to step 4.
4CHECK OUTPUT SIGNAL OF ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 5 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 7.Go to step 5.
Page 1277 of 2453
EN(H6DO)(diag)-116
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
P: DTC P0058 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 2 SENSOR 2)
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
HIGH (BANK 2 SENSOR 2), Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
Page 1279 of 2453
EN(H6DO)(diag)-118
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
2CHECK CURRENT DATA.
1) Turn the ignition switch to OFF.
2) Repair the battery short circuit of harness
between ECM and rear oxygen sensor con-
nector.
3) Turn the ignition switch to ON.
4) Read the data of rear oxygen sensor heater
current using Subaru Select Monitor or general
scan tool.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the current more than 7 A? Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
END.
3CHECK POOR CONTACT.
Check poor contact of ECM connector.
Is there poor contact in ECM
connector?
Repair poor con-
tact in ECM con-
nector.
END.
Step Check Yes No
Page 1455 of 2453

EN(H6DO)(diag)-294
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
CP:DTC P0464 FUEL LEVEL SENSOR CIRCUIT INTERMITTENT
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
TERMITTENT, Diagnostic Trouble Code (DTC) Detecting Criteria.>
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
CQ:DTC P0483 COOLING FAN RATIONALITY CHECK
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
•Occurrence of noise
•Overheating
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
NOTE:
If the vehicle, with the engine idling, is placed very close to a wall or another vehicle, preventing normal cool-
ing function, the OBD system may detect malfunction.
Step Check Yes No
1CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0464 displayed on the
display?
Check the combi-
nation meter.
Combination
Meter.>
Te m p o r a r y p o o r
contact occurs.
Step Check Yes No
1CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Check the appro-
priate DTC using
the “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
Check radiator fan,
fan motor and
thermostat and if
thermostat is
stuck, replace
thermostat.
to CO(H6DO)-21,
Radiator Main Fan
and Fan Motor.>
CO(H6DO)-25,
Radiator Sub Fan
and Fan Motor.>
Page 1464 of 2453

EN(H6DO)(diag)-303
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
DA:DTC P0638 THROTTLE ACTUATOR CONTROL RANGE/PERFORMANCE
(BANK 1)
NOTE:
For the diagnostic procedure, refer to DTC P2101.
ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
DB:DTC P0691 COOLING FAN 1 CONTROL CIRCUIT LOW
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
LOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
•Radiator fan does not operate properly.
•Overheating
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
Step Check Yes No
1CHECK INPUT VOLTAGE FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 7 (+) — Chassis ground (–):
(B135) No. 2 (+) — Chassis ground (–):
Is the voltage 10 — 13 V? Go to step 2.Repair the open or
ground short cir-
cuit of power sup-
ply circuit.
2CHECK INPUT VOLTAGE FROM ECM.
1) Start the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 7 (+) — Chassis ground (–):
(B135) No. 2 (+) — Chassis ground (–):
Is the voltage 13 — 15 V? Go to step 3.Repair the open or
ground short cir-
cuit of power sup-
ply circuit.
3CHECK ECM GROUND HARNESS.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 3 (+) — Chassis ground (–):
(B134) No. 5 (+) — Chassis ground (–):
(B137) No. 1 (+) — Chassis ground (–):
(B137) No. 2 (+) — Chassis ground (–):
(B137) No. 3 (+) — Chassis ground (–):
(B137) No. 7 (+) — Chassis ground (–):
Is the voltage less than 1 V? Repair poor con-
tact in ECM con-
nector. Replace
the ECM if defec-
tive.
FU(H6DO)-32,
Engine Control
Module (ECM).>
Fur ther tighten the
engine ground ter-
minal.
Step Check Yes No
1CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0691 displayed? Check the radiator
fan system.
to CO(H6DO)-7,
Radiator Fan Sys-
tem.>
Te m p o r a r y p o o r
contact occurs.
Page 1465 of 2453

EN(H6DO)(diag)-304
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
DC:DTC P0692 COOLING FAN 1 CONTROL CIRCUIT HIGH
DTC DETECTING CONDITION:
•Detected when two consecutive driving cycles with fault occur.
•GENERAL DESCRIPTION
HIGH, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
•Radiator fan does not operate properly.
•Overheating
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
DD:DTC P0700 TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
NOTE:
For the diagnostic procedure, refer to AT section.
DE:DTC P1152 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (LOW) (BANK 1
SENSOR 1)
NOTE:
For diagnostic procedure, refer to DTC P1153.
CIRCUIT RANGE/PERFORMANCE (HIGH) (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
Step Check Yes No
1CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0692 displayed? Check the radiator
fan system.
to CO(H6DO)-7,
Radiator Fan Sys-
tem.>
Te m p o r a r y p o o r
contact occurs.