EN(H6DO)(diag)-327
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
oil flow control solenoid valve.
3) Measure the resistance between oil flow
control solenoid valve and engine ground.
Connector & terminal
(E68) No. 1 — Engine ground:
(E68) No. 2 — Engine ground:
Is the resistance more than 1
MΩ?
Go to step 2.Repair the short
circuit between
ECM and oil flow
control solenoid
valve connector.
2CHECK OIL FLOW CONTROL SOLENOID
VALVE.
1) Remove the oil flow control solenoid valve
connector.
2) Measure the resistance between oil flow
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:
Is the resistance between 6 —
12 Ω?
Repair the poor
contact of ECM
and oil flow con-
trol solenoid valve.
Replace the oil
flow control sole-
noid valve.
Oil Flow Control
Solenoid Valve.>
EN(H6DO)(diag)-333
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
9CHECK 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”.
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)?
Go to step 10.Check the mass
air flow and intake
air temperature
sensor.
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
10 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 26 — Chassis ground:
(B134) No. 33 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 11.Repair the ground
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
11 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 26 (+) — Chassis ground (–):
(B134) No. 33 (+) — Chassis ground (–):
Is the voltage more than 8 V? Go to step 12.Repair the battery
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
12 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 26 — (E47) No. 4:
(B134) No. 33 — (E47) No. 3:
Is the resistance less than 1
Ω?
Go to step 13.Repair the open
circuit of harness
between ECM and
front oxygen (A/F)
sensor connector.
Step Check Yes No
EN(H6DO)(diag)-334
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
13 CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and keep
the engine speed at 5,000 rpm.
2) Read the data of rear oxygen 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”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage more than 490
mV?
Go to step 16.Go to step 14.
14 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance of harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B137) No. 24 — (E61) No. 3:
(B136) No. 35 — (E61) No. 4:
Is the resistance more than
3Ω?
Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
Go to step 15.
15 CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
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 harness connector and chassis ground.
Connector & terminal
(E61) No. 3 (+) — Chassis ground (–):
Is the voltage 0.2 — 0.5 V? Replace the rear
oxygen sensor.
Rear Oxygen Sen-
sor.>
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween rear oxy-
gen sensor and
ECM connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
in ECM connec-
tor
Step Check Yes No
EN(H6DO)(diag)-335
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
16 CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and rap-
idly reduce the engine speed from 5,000 rpm.
2) Read the data of rear oxygen 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”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage 250 mV or less? Contact with SOA
Service Center.
Go to step 17.
17 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance of harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B137) No. 24 — (E61) No. 3:
(B136) No. 35 — (E61) No. 4:
Is the resistance more than
3Ω?
Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
Go to step 18.
18 CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
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 harness connector and chassis ground.
Connector & terminal
(E61) No. 3 (+) — Chassis ground (–):
Is the voltage 0.2 — 0.5 V? Replace the rear
oxygen sensor.
Rear Oxygen Sen-
sor.>
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween rear oxy-
gen sensor and
ECM connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
in ECM connec-
tor
Step Check Yes No
EN(H6DO)(diag)-341
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
9CHECK 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”.
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)?
Go to step 10.Check the mass
air flow and intake
air temperature
sensor.
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
10 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 26 — Chassis ground:
(B134) No. 33 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 11.Repair the ground
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
11 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 26 (+) — Chassis ground (–):
(B134) No. 33 (+) — Chassis ground (–):
Is the voltage more than 8 V? Go to step 12.Repair the battery
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
12 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 26 — (E47) No. 4:
(B134) No. 33 — (E47) No. 3:
Is the resistance less than 1
Ω?
Go to step 13.Repair the open
circuit of harness
between ECM and
front oxygen (A/F)
sensor connector.
Step Check Yes No
EN(H6DO)(diag)-342
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
13 CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and keep
the engine speed at 5,000 rpm.
2) Read the data of rear oxygen 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”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage more than 490
mV?
Go to step 16.Go to step 14.
14 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance of harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B135) No. 4 — (E61) No. 3:
(B135) No. 30 — (E61) No. 4:
Is the resistance more than
3Ω?
Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
Go to step 15.
15 CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
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 harness connector and chassis ground.
Connector & terminal
(E61) No. 3 (+) — Chassis ground (–):
Is the voltage 0.2 — 0.5 V? Replace the rear
oxygen sensor.
Rear Oxygen Sen-
sor.>
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween rear oxy-
gen sensor and
ECM connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
in ECM connec-
tor
Step Check Yes No
EN(H6DO)(diag)-343
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
16 CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and rap-
idly reduce the engine speed from 5,000 rpm.
2) Read the data of rear oxygen 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”.
tor.>
•General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage 250 mV or less? Contact with SOA
Service Center.
Go to step 17.
17 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance of harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B135) No. 4 — (E61) No. 3:
(B135) No. 30 — (E61) No. 4:
Is the resistance more than
3Ω?
Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
Go to step 18.
18 CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
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 harness connector and chassis ground.
Connector & terminal
(E61) No. 3 (+) — Chassis ground (–):
Is the voltage 0.2 — 0.5 V? Replace the rear
oxygen sensor.
Rear Oxygen Sen-
sor.>
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween rear oxy-
gen sensor and
ECM connector
•Poor contact
in rear oxygen
sensor connec-
tor
•Poor contact
in ECM connec-
tor
Step Check Yes No
EN(H6DO)(diag)-349
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
9CHECK 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”.
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)?
Go to step 10.Check the mass
air flow and intake
air temperature
sensor.
Mass Air Flow and
Intake Air Temper-
ature Sensor.>
10 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 27 — Chassis ground:
(B134) No. 34 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 11.Repair the ground
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
11 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 27 (+) — Chassis ground (–):
(B134) No. 34 (+) — Chassis ground (–):
Is the voltage more than 8 V? Go to step 12.Repair the ground
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
12 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134) No. 27 — (E24) No. 4:
(B134) No. 34 — (E24) No. 3:
Is the resistance less than 1
Ω?
Go to step 13.Repair the open
circuit of harness
between ECM and
front oxygen (A/F)
sensor connector.
Step Check Yes No