Page 1308 of 2453

EN(H6DO)(diag)-147
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of mass air flow and intake
air temperature sensor signal 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 intake air temperature
less than –40°C (–40°F) ?
Go to step 2.Repair the poor
contact.
NOTE:
In this case, repair
the following item:
•Poor contact
in mass air flow
and intake air
temperature
sensor
•Poor contact
in ECM
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
2CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air
flow and intake air temperature sensor.
3) Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.
Go to step 3.
3CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.
Go to step 4.
Page 1309 of 2453

EN(H6DO)(diag)-148
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
4CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (–):
Is the voltage more than 3 V? Go to step 5.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Broken wire
between mass
air flow and in-
take air temper-
ature sensor
and ECM con-
nector.
•Poor contact
in mass air flow
and intake air
temperature
sensor
•Poor contact
in ECM
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
5CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between mass air flow and intake air tempera-
ture sensor connector and engine ground.
Connector & terminal
(B3) No. 5 — Engine ground:
Is the resistance less than 5
Ω?
Replace the mass
air flow and intake
air temperature
sensor.
FU(H6DO)-23,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Broken wire
between mass
air flow and in-
take air temper-
ature sensor
and ECM con-
nector.
•Poor contact
in mass air flow
and intake air
temperature
sensor
•Poor contact
in ECM
•Poor contact
of joint connec-
tor
Step Check Yes No
Page 1310 of 2453
EN(H6DO)(diag)-149
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
AD:DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT
DTC DETECTING CONDITION:
•Immediately at fault recognition
•GENERAL DESCRIPTION
CIRCUIT LOW INPUT, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
•Hard to start
•Erroneous idling
•Poor driving performance
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
WIRING DIAGRAM:
EN-03661
2934
198
B134ECM
12
E2
B21
E8
ENGINECOOLANTTEMPERATURE SENSOR
E8
B21
123412131415567816171819910 1120212223 24 25 2627 28 29 3031 32 33
3534 37363938 41404342 4445 47464948 51505352 54
12
B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34
Page 1311 of 2453

EN(H6DO)(diag)-150
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of engine coolant tempera-
ture sensor signal 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 engine coolant tempera-
ture above 150°C (302°F) ?
Go to step 2.Repair the poor
contact.
NOTE:
In this case, repair
the following item:
•Poor contact
of engine cool-
ant tempera-
ture sensor
•Poor contact
in ECM
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
2CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the engine
coolant temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of engine coolant tempera-
ture sensor signal 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 engine coolant tempera-
ture less than –40°C (–40°F) ?
Replace the
engine coolant
temperature sen-
sor.
FU(H6DO)-17,
Engine Coolant
Te m p e r a t u r e S e n -
sor.>
Repair the ground
short circuit of har-
ness between
engine coolant
temperature sen-
sor and ECM con-
nector.
Page 1312 of 2453
EN(H6DO)(diag)-151
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
AE:DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT
DTC DETECTING CONDITION:
•Immediately at fault recognition
•GENERAL DESCRIPTION
CIRCUIT HIGH INPUT, Diagnostic Trouble Code (DTC) Detecting Criteria.>
TROUBLE SYMPTOM:
•Hard to start
•Erroneous idling
•Poor driving performance
CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode
OPERATION, Clear Memory Mode.> and Inspection Mode
Inspection Mode.>.
WIRING DIAGRAM:
EN-03661
2934
198
B134ECM
12
E2
B21
E8
ENGINECOOLANTTEMPERATURE SENSOR
E8
B21
123412131415567816171819910 1120212223 24 25 2627 28 29 3031 32 33
3534 37363938 41404342 4445 47464948 51505352 54
12
B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34
Page 1313 of 2453

EN(H6DO)(diag)-152
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of engine coolant tempera-
ture sensor signal 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 engine coolant tempera-
ture less than –40°C (–40°F) ?
Go to step 2.Repair the poor
contact.
NOTE:
In this case, repair
the following item:
•Poor contact
of engine cool-
ant tempera-
ture sensor
•Poor contact
in ECM
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
2CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the engine
coolant temperature sensor.
3) Measure the voltage between engine cool-
ant temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
ECM and engine
coolant tempera-
ture sensor con-
nector.
Go to step 3.
3CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between engine cool-
ant temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
ECM and engine
coolant tempera-
ture sensor con-
nector.
Go to step 4.
Page 1314 of 2453

EN(H6DO)(diag)-153
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
4CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
Measure the voltage between engine coolant
temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) — Engine ground (–):
Is the voltage more than 4 V? Go to step 5.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
engine coolant
temperature
sensor connec-
tor
•Poor contact
of engine cool-
ant tempera-
ture sensor
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
5CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between engine coolant temperature sensor
connector and engine ground.
Connector & terminal
(E8) No. 1 — Engine ground:
Is the resistance less than 5
Ω?
Replace the
engine coolant
temperature sen-
sor.
FU(H6DO)-17,
Engine Coolant
Te m p e r a t u r e S e n -
sor.>
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
engine coolant
temperature
sensor connec-
tor
•Poor contact
of engine cool-
ant tempera-
ture sensor
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
Step Check Yes No
Page 1316 of 2453
EN(H6DO)(diag)-155
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
WIRING DIAGRAM:
EN-03739
SBF-7
B134A:B137B136D:
B362
E1
B20
C:E
EE
C1C21
38392019
1615
*
*
E2
B21
E57
461235
D4D5A29A19A5D3D7A3D2D1
3536375234
A28A18C6
ECM
57
86
B362
12
78
34
56
B21
12345678910 1112 1314 1516 1718 1920 21222324 25
34 35 36 37 38 39 40 41
48 49 50 51 52 53 5442 43 44 45 46 47
26 2728 2930 313233
B122
12345678
1289563410 11 121920 2129 3031
13 14 15161727281822 2324 25 267
32 3334 35
B136C:
12789563410 11 121920 2129 30 31
13 14 151617
27 281822 23 24 2526
B137D:
BATTERY
MAIN RELAY
ELECTRONICTHROTTLECONTROL RELAY
ELECTRONICTHROTTLE CONTROL
B20
1234567891011 121314 15 16
E57
123456
B122
*: TERMINAL NO. OPTIONAL ARRANGEMENT
A:B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34