EN(H6DO)(diag)-205
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)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0157.
Go to step 2.
2CHECK 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 5.Go to step 3.
3CHECK 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. 15 — (E25) No. 3:
(B135) No. 30 — (E25) 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 4.
4CHECK 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
(E25) 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
EN(H6DO)(diag)-209
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)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0138.
Go to step 2.
2CHECK 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? Go to step 5.Go to step 3.
3CHECK 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. 15 — (E25) No. 3:
(B135) No. 30 — (E25) 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 4.
4CHECK 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
(E25) 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
EN(H6DO)(diag)-213
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)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0159.
Go to step 2.
2CHECK 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. 15 — (E25) No. 3:
Is the resistance less than 1
Ω?
Go to step 3.Repair the open
circuit of harness
between ECM and
rear oxygen sen-
sor connector.
3CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
Measure the resistance between rear oxygen
sensor harness connector and chassis ground.
Connector & terminal
(B25) No. 3 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 4.Repair the chas-
sis short circuit of
harness.
4CHECK REAR OXYGEN SENSOR.
Measure the resistance between connector
terminals of rear oxygen sensor.
Te r m i n a l s
No. 3 — No. 4
Is the resistance less than 1
Ω?
Replace the rear
oxygen sensor.
Rear Oxygen Sen-
sor.>
Te m p o r a r y p o o r
contact occurs.
Check poor con-
tact of connector.
EN(H6DO)(diag)-216
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)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0138.
Go to step 2.
2CHECK 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 more than 490
mV?
Go to step 6.Go to step 3.
3CHECK 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? Go to step 6.Go to step 4.
4CHECK 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. 15 — (E25) No. 3:
(B135) No. 30 — (E25) 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 5.
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)”.
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.
Te m p e r a t u r e S e n -
sor.>
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)”.
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.
Te m p e r a t u r e S e n -
sor.>
EN(H6DO)(diag)-245
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)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0301, P0302,
P303, P0304,
P0305 and P0306.
Go to step 2.
2CHECK OUTPUT SIGNAL OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground on faulty cylinders.
Connector & terminal
#1 (B137) No. 8 (+) — Chassis ground (–):
#2 (B137) No. 9 (+) — Chassis ground (–):
#3 (B137) No. 10 (+) — Chassis ground (–):
#4 (B137) No. 11 (+) — Chassis ground (–):
#5 (B137) No. 12 (+) — Chassis ground (–):
#6 (B137) No. 13 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 7.Go to step 3.
3CHECK HARNESS BETWEEN FUEL INJEC-
TOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel injector
on faulty cylinders.
3) Measure the resistance between ECM con-
nector and engine ground on faulty cylinders.
Connector & terminal
#1 (E5) No. 1 — Engine ground:
#2 (E16) No. 1 — Engine ground:
#3 (E6) No. 1 — Engine ground:
#4 (E17) No. 1 — Engine ground:
#5 (E43) No. 1 — Engine ground:
#6 (E44) No. 1 — Engine ground:
Is the resistance more than 1
MΩ?
Go to step 4.Repair the ground
short circuit of har-
ness between fuel
injector and ECM
connector.
4CHECK HARNESS BETWEEN FUEL INJEC-
TOR AND ECM CONNECTOR.
Measure the resistance of harness connector
between ECM connector and fuel injector on
faulty cylinders.
Connector & terminal
#1 (B137) No. 8 — (E5) No. 1:
#2 (B137) No. 9 — (E16) No. 1:
#3 (B137) No. 10 — (E6) No. 1:
#4 (B137) No. 11 — (E17) No. 1:
#5 (B137) No. 12 — (E43) No. 1:
#6 (B137) No. 13 — (E44) No. 1:
Is the resistance less than 1
Ω?
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 injector
connector
•Poor contact
of coupling con-
nector
5CHECK FUEL INJECTOR.
Measure the resistance between fuel injector
terminals on faulty cylinder.
Te r m i n a l s
No. 1 — No. 2:
Is the resistance between 5 —
20 Ω?
Go to step 6.Replace the faulty
fuel injector.
Fuel Injector.>
EN(H6DO)(diag)-247
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
12 CHECK FUEL LEVEL.Is the fuel meter indication
lower than the “Lower” level?
Replenish fuel so
that fuel meter
indication is higher
than the “Lower”
level. After replen-
ishing fuel, Go to
step 13.
Go to step 13.
13 CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1) Clear the memory using the Subaru Select
Monitor or the general scan tool.
NOTE:•Subaru Select Monitor
•General scan tool
Refer to operating manuals for the general
scan tool.
2) Start the engine, and drive the vehicle more
than 10 minutes.
Does the malfunction indicator
light illuminate or blink?
Go to step 15.Go to step 14.
14 CHECK CAUSE OF MISFIRE.Has the cause of misfire been
detected while running the
engine?
Finish diagnostics
operation, if the
engine has no
abnormality.
Repair the poor
contact.
NOTE:In this case, repair
the following item:
•Poor contact
of ignition coil
connector
•Poor contact
of fuel injector
connector on
faulty cylinders
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
15 CHECK AIR INTAKE SYSTEM.Is there any fault in air intake
system?
Repair the air
intake system.
NOTE:
Check the follow-
ing item.
•Are there air
leaks or air suc-
tion caused by
loose or dislo-
cated nuts and
bolts?
•Are there
cracks or any
disconnection
of hoses?
Go to step 16.
16 CHECK MISFIRE SYMPTOM.
1) Turn the ignition switch to ON.
2) Read DTC.
Does the Subaru Select Moni-
tor or general scan tool indi-
cate only one DTC?
Go to step 22.Go to step 17.
17 CHECK ANY OTHER DTC ON DISPLAY.Are DTC P0301 and P0302
displayed?
Go to step 23.Go to step 18.
Step Check Yes No