Page 1913 of 2890

OBD0145A
10E2
CHECK DATA FOR CONTROL.
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 ON and Subaru Select Monitor or
the OBD-II general scan tool switch ON.
4) Start engine.
B2M0756
5) Read data on Subaru Select Monitor or the OBD-II gen-
eral scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F21 and F20
F21: Display shows pressure signal value sent from the
pressure sensor.
F20: Display shows pressure signal value sent from the
pressure sensor.
: Is the value more than 85 kPa in function
mode F21?
: Go to step10E3.
: Go to next.
B2M0755
: Is the value less than 32 kPa in function
mode F20?
: Go to step10E4.
: Go to next.
B2M0755
: Is the value more than 133 kPa in function
mode F20?
: Replace pressure sensor.
: Repair poor contact in pressure sensor connector,
pressure sources switching solenoid valve
connector, and ECM connector.
OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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10. Diagnostics Chart with Trouble Code
Page 1914 of 2890

B2M0711A
10E3
CHECK VACUUM HOSE.
: Is there a fault in vacuum hose?
NOTE:
Check the following items.
Disconnection of the vacuum hose from pressure
sources switching solenoid valve to intake manifold
Holes in the vacuum hose between pressure sources
switching solenoid valve to intake manifold
Clogging of the vacuum hose between pressure sources
switching solenoid valve to intake manifold
Disconnection of the vacuum hose from pressure sensor
to pressure sources switching solenoid valve
Holes in the vacuum hose between pressure sensor and
pressure sources switching solenoid valve
Clogging of the vacuum hose between pressure sensor
and pressure sources switching solenoid valve
Clogging of the filter
: Repair or replace hoses or filter.
: Go to step10E4.
OBD0005B
10E4CHECK PRESSURE SOURCES SWITCH-
ING SOLENOID VALVE.
1) Turn ignition switch to OFF.
2) Connect test mode connector.
3) Turn ignition switch to ON.
: Does pressure sources switching solenoid
valve produce operating sound? (ON↔
OFF each 1.5 sec.)
NOTE:
Pressure sources switching solenoid valve operation check
can also be executed using Subaru Select Monitor (Func-
tion mode: FD10). For the procedure, refer to“COMPUL-
SORY VALVE OPERATION CHECK MODE”2-7 [T3F0].
: Replace pressure sensor.
: Replace pressure sources switching solenoid
valve.
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10. Diagnostics Chart with Trouble Code
Page 1915 of 2890
OBD0172
F: DTC P0115
—ENGINE COOLANT TEMPERATURE
SENSOR CIRCUIT MALFUNCTION (TW)—
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
Hard to start
Erroneous idling
Poor driving performance
10F1Connect Subaru Select Monitor or the OBD-II
general scan tool, and read data.
10F2Check harness between engine coolant
temperature sensor and ECM connector.
10F3Check harness between engine coolant
temperature sensor and ECM connector.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
WIRING DIAGRAM:
B2M0539
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10. Diagnostics Chart with Trouble Code
Page 1916 of 2890

OBD0145A
10F1CONNECT 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.
B2M0479
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F04
F04: Water temperature is indicated in“°C”and“°F”.
: Is the value greater than 150°Cor300°Fin
function mode F04?
: Go to step10F2.
: Go to next.
B2M0479
: Is the value less than 40°Cor 40°Fin
function mode F04?
: Go to step10F3.
: Repair poor contact.
NOTE:
In this case, repair the following:
Poor contact in engine coolant temperature sensor
Poor contact in ECM
Poor contact in coupling connector (B21)
OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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10. Diagnostics Chart with Trouble Code
Page 1917 of 2890

OBD0618A
10F2CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove idle air control solenoid valve by-pass air hose.
3) Disconnect connector from engine coolant temperature
sensor.
OBD0145A
4) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
5) Turn ignition switch and Subaru Select Monitor or
OBD-II general scan tool switch to ON.
B2M0479
6) Read data on Subaru Select Monitor or the OBD-II gen-
eral scan tool.
Subaru Select Monitor
Designate mode using function key.
Function mode: F04
F04: Water temperature is indicated in“°C”and“°F”.
: Is the value less than 40°Cor 40°Fin
function mode F04?
: Replace engine coolant temperature sensor.
: Repair short circuit in harness between engine
coolant temperature sensor and ECM connector.
OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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10. Diagnostics Chart with Trouble Code
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OBD0618A
10F3CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Remove idle air control solenoid valve by-pass air hose.
3) Disconnect connector from engine coolant temperature
sensor.
4) Turn ignition switch to ON.
OBD0696A
5) Measure voltage between engine coolant temperature
sensor connector and engine ground.
: Connector & terminal
(E8) No. 1 (+)—Engine ground ( ):
Is the voltage more than 4 V?
: Go to next step 6).
: Repair harness and connector.
NOTE:
In this case, repair the following:
Open circuit in harness between ECM and engine cool-
ant temperature sensor connector
Poor contact in engine coolant temperature sensor con-
nector
Poor contact in ECM connector
Poor contact in coupling connector (B21)
OBD0697A
6) Turn ignition switch to OFF.
7) Measure resistance of harness between engine coolant
temperature sensor connector and engine ground.
: Connector & terminal
(E8) No. 2—Engine ground:
Is the resistance less than 5Ω?
: Replace engine coolant temperature sensor.
: Repair harness and connector.
NOTE:
In this case, repair the following:
Open circuit in harness between ECM and engine cool-
ant temperature sensor connector
Poor contact in engine coolant temperature sensor con-
nector
Poor contact in ECM connector
Poor contact in coupling connector (B21)
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10. Diagnostics Chart with Trouble Code
Page 1919 of 2890
OBD0181
G: DTC P0120
—THROTTLE POSITION SENSOR CIRCUIT
MALFUNCTION (THV)—
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
Erroneous idling
Engine stalls.
Poor driving performance
10G1Connect Subaru Select Monitor or the OBD-II
general scan tool and read data.
10G2Check input signal for ECM. (Using voltage
meter and Subaru select monitor.)
10G3Check harness between ECM and throttle
position sensor connector.
10G4Check harness between throttle position
sensor and body connector.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.
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10. Diagnostics Chart with Trouble Code
Page 1920 of 2890
WIRING DIAGRAM:
B2M0540
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10. Diagnostics Chart with Trouble Code