Page 1380 of 2453

EN(H6DO)(diag)-219
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
5CHECK MASS AIR FLOW AND INTAKE AIR
TEMPERATURE SENSOR
1) Start the engine and warm-up engine until
coolant temperature is greater than 60°C
(140°F).
2) Place the select lever in “N” or “P” position.
3) Turn the A/C switch to OFF.
4) Turn all the accessory switches to OFF.
5) Read the data of mass air flow and intake
air temperature sensor signal using Subaru
Select Monitor.
NOTE:
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
Is the measured value 3.1 —
4.3 g/s (0.4 — 0.6 lb/m)?
Go to step 6.Replace the mass
air flow and intake
air temperature
sensor.
FU(H6DO)-23,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
6CHECK MASS AIR FLOW AND INTAKE AIR
TEMPERATURE SENSOR.
1) Start the engine and warm-up engine until
coolant temperature is greater than 60°C
(140°F).
2) Place the shift lever in neutral position.
3) Turn the A/C switch to OFF.
4) Turn all the accessory switches to OFF.
5) Open the front hood.
6) Measure the ambient temperature.
7) 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.
Subtract ambient temperature
from intake air temperature. Is
the obtained value –10 — 50°C
(14 — 122°F)?
Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
Check the mass
air flow and intake
air temperature
sensor.
FU(H6DO)-23,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
Step Check Yes No
Page 1382 of 2453
EN(H6DO)(diag)-221
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
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).>
NOTE:In this case, it is
not necessary to
inspect DTC
P0181.
Replace the fuel
temperature sen-
sor.
EC(H6DO)-8, Fuel
Te m p e r a t u r e S e n -
sor.>
Page 1384 of 2453

EN(H6DO)(diag)-223
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 fuel temperature sensor
signal using Subaru Select Monitor.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
Is the temperature above
120°C (248°F)?
Go to step 2.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.
2CHECK CURRENT DATA.
1) Turn the ignition switch to OFF.
2) Remove the access hole lid.
3) Disconnect the connector from fuel pump.
4) Turn the ignition switch to ON.
5) Read the data of fuel temperature sensor
signal using Subaru Select Monitor.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
Is the temperature less than -
40°C (-40°F)?
Replace the fuel
temperature sen-
sor.
EC(H6DO)-8, Fuel
Te m p e r a t u r e S e n -
sor.>
Repair the ground
short circuit of har-
ness between the
fuel pump and
ECM connector.
Page 1386 of 2453

EN(H6DO)(diag)-225
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 fuel temperature sensor
signal using Subaru Select Monitor.
NOTE:•Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
Is the 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 fuel pump
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
2 CHECK HARNESS BETWEEN FUEL TEM-
PERATURE SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Remove the access hole lid.
3) Disconnect the connector from fuel pump.
4) Measure the voltage between fuel pump
connector and chassis ground.
Connector & terminal
(R58) No. 2 (+) — Chassis ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
ECM and fuel
pump connector.
Go to step 3.
3 CHECK HARNESS BETWEEN FUEL TEM-
PERATURE SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between fuel pump
connector and chassis ground.
Connector & terminal
(R58) No. 2 (+) — Chassis ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
ECM and fuel
pump connector.
Go to step 4.
4 CHECK HARNESS BETWEEN FUEL TEM-
PERATURE SENSOR AND ECM CONNEC-
TOR.
Measure the voltage between fuel pump con-
nector and chassis ground.
Connector & terminal
(R58) No. 2 (+) — Chassis 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
fuel pump con-
nector
•Poor contact
in fuel pump
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
Page 1387 of 2453
EN(H6DO)(diag)-226
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
5 CHECK HARNESS BETWEEN FUEL TEM-
PERATURE SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between fuel pump connector and ECM.
Connector & terminal
(R58) No. 3 — (B135) No. 30:
Is the resistance less than 1
Ω?
Replace the fuel
temperature sen-
sor.
EC(H6DO)-8, Fuel
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
fuel pump con-
nector
•Poor contact
in fuel pump
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
•Poor contact
of joint connec-
tor
Step Check Yes No
Page 1389 of 2453
EN(H6DO)(diag)-228
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Check DTC using
“List of Diagnostic
Tr o u b l e C o d e
(DTC)”.
EN(H6DO)(diag)-
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0196.
Replace the oil
temperature sen-
sor.
FU(H6DO)-27, Oil
Te m p e r a t u r e S e n -
sor.>
Page 1391 of 2453
EN(H6DO)(diag)-230
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN OIL TEMPER-
ATURE SENSOR AND ECM CONNECTOR.
1) Disconnect the ECM connector and oil tem-
perature sensor connector.
2) Measure the resistance of harness
between oil temperature sensor connector and
engine ground.
Connector & terminal
(B134) No. 23 — Engine ground:
(B134) No. 29 — Engine ground:
Is the resistance more than 1
MΩ?
Go to step 2.Repair the ground
short circuit
between ECM and
oil temperature
sensor connector.
2CHECK POOR CONTACT.
Check poor contact of oil temperature sensor
connector.
Is there poor contact in oil tem-
perature sensor connector?
Repair the poor
contact.
Replace the oil
temperature sen-
sor.
FU(H6DO)-27, Oil
Te m p e r a t u r e S e n -
sor.>
Page 1393 of 2453

EN(H6DO)(diag)-232
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN OIL TEMPER-
ATURE SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from oil tempera-
ture sensor.
3) Measure the voltage between oil tempera-
ture sensor connector and engine ground.
Connector & terminal
(E75) No. 2 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
ECM and oil tem-
perature sensor
connector.
Go to step 2.
2CHECK HARNESS BETWEEN OIL TEMPER-
ATURE SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between oil tempera-
ture sensor connector and engine ground.
Connector & terminal
(E75) No. 2 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the battery
short circuit of har-
ness between
ECM and oil tem-
perature sensor
connector.
Go to step 3.
3CHECK HARNESS BETWEEN OIL TEMPER-
ATURE SENSOR AND ECM CONNECTOR.
Measure the voltage between oil temperature
sensor connector and engine ground.
Connector & terminal
(E75) No. 2 (+) — Engine ground (–):
Is the voltage more than 4 V? Go to step 4.Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following item:
•Open circuit
of harness be-
tween ECM and
oil temperature
sensor connec-
tor
•Poor contact
of oil tempera-
ture sensor con-
nector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector