EN(H6DO)(diag)-242
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
BN:DTC P0301 CYLINDER 1 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
BO:DTC P0302 CYLINDER 2 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
BP:DTC P0303 CYLINDER 3 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
BQ:DTC P0304 CYLINDER 4 MISFIRE DETECTED
NOTE:
For the diagnostic procedure, refer to DTC P0306.
5CHECK HARNESS BETWEEN FUEL PUMP
CONTROL UNIT AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of harness
between fuel pump control unit and ECM con-
nector.
Connector & terminal
(R122) No. 9 — (B135) No. 33:
(R122) No. 8 — (B136) No. 12:
Is the resistance less than 1
Ω?
Go to step 6.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
between fuel
pump control
unit and ECM
•Poor contact
of fuel pump
control unit and
ECM connector
6CHECK HARNESS BETWEEN FUEL PUMP
CONTROL UNIT AND ECM CONNECTOR.
Measure the resistance of harness between
fuel pump control unit and chassis ground.
Connector & terminal
(R122) No. 9 — Chassis ground:
(R122) No. 8 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 7.Repair the ground
short circuit
between fuel pump
control unit and
ECM.
7CHECK POOR CONTACT.
Check poor contact of ECM and fuel pump
control unit connector.
Is there poor contact of ECM
and fuel pump control unit con-
nector?
Repair the poor
contact of ECM and
fuel pump control
unit connector.
Go to step 8.
8CHECK EXPERIENCE OF RUNNING OUT OF
FUEL.
Has the vehicle experienced
running out of fuel?
Finish the diagno-
sis.
NOTE:
DTC may be re-
corded as a result
of fuel pump idling
while running out
of fuel.
Replace the fuel
pump control unit.
Fuel Pump Control
Unit.>
Step Check Yes No
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)-246
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
6CHECK POWER SUPPLY LINE.
1) Turn the ignition switch to ON.
2) Measure the voltage between fuel injector
and engine ground on faulty cylinders.
Connector & terminal
#1 (E5) No. 2 (+) — Engine ground (–):
#2 (E16) No. 2 (+) — Engine ground (–):
#3 (E6) No. 2 (+) — Engine ground (–):
#4 (E17) No. 2 (+) — Engine ground (–):
#5 (E43) No. 2 (+) — Engine ground (–):
#6 (E44) No. 2 (+) — Engine ground (–):
Is the voltage more than 10 V? Repair the poor
contact of all con-
nectors in fuel
injector circuit.
Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween main re-
lay and fuel
injector on
faulty cylinders
•Poor contact
of coupling con-
nector
•Poor contact
of main relay
connector
•Poor contact
of fuel injector
connector on
faulty cylinders
7CHECK 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) Turn the ignition switch to ON.
4) 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? Repair the battery
short circuit of har-
ness between
ECM and fuel
injector. After
repair, replace the
ECM.
Engine Control
Module (ECM).>
Go to step 8.
8CHECK FUEL INJECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between fuel injec-
tor terminals on faulty cylinder.
Te r m i n a l s
No. 1 — No. 2:
Is the resistance less than 1
Ω?
Replace the faulty
fuel injector
Fuel Injector.> and
ECM.
Engine Control
Module (ECM).>
Go to step 9.
9CHECK INSTALLATION OF CAMSHAFT PO-
SITION SENSOR/CRANKSHAFT POSITION
SENSOR.
Is the camshaft position sensor
or crankshaft position sensor
loosely installed?
Tighten the cam-
shaft position sen-
sor or crankshaft
position sensor.
Go to step 10.
10 CHECK CRANK PLATE.Is the crank sprocket rusted or
the teeth of crank plate bro-
ken?
Replace the crank
plate.
Cylinder Block.>
Go to step 11.
11 CHECK INSTALLATION CONDITION OF
TIMING CHAIN.
Tu r n t h e c r a n k s h a f t u s i n g S T, a n d a l i g n a l i g n -
ment mark on crank sprocket with alignment
mark on cylinder block.
ST 18252AA000 CRANKSHAFT
SOCKET
Is the timing chain dislocated
from its proper position?
Correct the instal-
lation condition of
timing chain.
Timing Chain
Assembly.>
Go to step 12.
Step Check Yes No
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
EN(H6DO)(diag)-248
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
18 CHECK DTC ON DISPLAY.Are DTC P0303 and P0304
displayed?
Go to step 24.Go to step 19.
19 CHECK DTC ON DISPLAY.Are DTC P0305 and P0306
displayed?
Go to step 25.Go to step 20.
20 CHECK DTC ON DISPLAY.Are DTC P0301, P0303 and
P0305 displayed?
Go to step 26.Go to step 21.
21 CHECK DTC ON DISPLAY.Are DTC P0302, P0304 and
P0306 displayed?
Go to step 27.Go to step 28.
22 ONLY ONE CYLINDERIs there any fault in the cylin-
der?
Repair or replace
faulty par ts.
NOTE:Check the follow-
ing item.
•Spark plug
•Fuel injector
•Compression
ratio
Check DTC
P0171, P0172,
P0174 or P0175
using “List of Diag-
nostic Trouble
Code (DTC)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
23 GROUP OF #1 AND #2 CYLINDERSAre there any faults in #1 and
#2 cylinders?
Repair or replace
faulty par ts.
NOTE:•Check the fol-
lowing item.
•Spark plug
•Fuel injec-
tor
•Ignition
coil
•Compres-
sion ratio
•If any fault
are not found,
check the “IG-
NITION CON-
TROL
SYSTEM” of #1
and #2 cylin-
ders side.
EN(H6DO)(di-
ag)-63, IGNI-
TION
CONTROL
SYSTEM, Diag-
nostics for En-
gine Starting
Failure.>
Check DTC
P0171, P0172,
P0174 or P0175
using “List of Diag-
nostic Trouble
Code (DTC)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
Step Check Yes No
EN(H6DO)(diag)-249
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
24 GROUP OF #3 AND #4 CYLINDERSAre there any faults in #3 and
#4 cylinders?
Repair or replace
faulty par ts.
NOTE:
•Check the fol-
lowing item.
•Spark plug
•Fuel injec-
tor
•Ignition
coil
•If any fault
are not found,
check the “IG-
NITION CON-
TROL
SYSTEM” of #3
and #4 cylin-
ders side.
EN(H6DO)(di-
ag)-63, IGNI-
TION
CONTROL
SYSTEM, Diag-
nostics for En-
gine Starting
Failure.>
Check DTC
P0171, P0172,
P0174 or P0175
using “List of Diag-
nostic Trouble
Code (DTC)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
25 GROUP OF #5 AND #6 CYLINDERSAre there any faults in #5 and
#6 cylinders?
Repair or replace
faulty par ts.
NOTE:•Check the fol-
lowing item.
•Spark plug
•Fuel injec-
tor
•Ignition
coil
•Compres-
sion ratio
•If any fault
are not found,
check the “IG-
NITION CON-
TROL
SYSTEM” of #5
and #6 cylin-
ders side.
EN(H6DO)(di-
ag)-63, IGNI-
TION
CONTROL
SYSTEM, Diag-
nostics for En-
gine Starting
Failure.>
Check DTC
P0171, P0172,
P0174 or P0175
using “List of Diag-
nostic Trouble
Code (DTC)”.
69, List of Diag-
nostic Trouble
Code (DTC).>
Step Check Yes No
EN(H6DO)(diag)-252
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN KNOCK SEN-
SOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance between ECM har-
ness connector and chassis ground.
Connector & terminal
(B134) No. 15 — Chassis ground:
Is the resistance more than
700 kΩ?
Go to step 2.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Open circuit
of harness be-
tween knock
sensor and
ECM connector
•Poor contact
of knock sensor
connector
•Poor contact
of coupling con-
nector
2CHECK KNOCK SENSOR.
1) Disconnect the connector from knock sen-
sor.
2) Measure the resistance between knock
sensor connector terminal and engine ground.
Te r m i n a l s
No. 2 — Engine ground:
Is the resistance more than
700 kΩ?
Go to step 3.Repair the har-
ness and connec-
tor.
NOTE:In this case, repair
the following item:
•Poor contact
of knock sensor
connector
3CHECK INSTALLATION CONDITION OF
KNOCK SENSOR
Is the knock sensor installation
bolt tightened securely?
Replace the knock
sensor.
Knock Sensor.>
Tighten the knock
sensor installation
bolt securely.
EN(H6DO)(diag)-254
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step Check Yes No
1CHECK HARNESS BETWEEN KNOCK SEN-
SOR AND ECM CONNECTOR.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 15 — Chassis ground:
Is the resistance less than 400
kΩ?
Go to step 2.Go to step 3.
2CHECK KNOCK SENSOR.
1) Disconnect the connector from knock sen-
sor.
2) Measure the resistance between knock
sensor connector terminal and engine ground.
Te r m i n a l s
No. 2 — Engine ground:
Is the resistance less than 400
kΩ?
Replace the knock
sensor.
Knock Sensor.>
Repair the ground
short circuit of har-
ness between
knock sensor con-
nector and ECM
connector.
NOTE:
The harness be-
tween both con-
nectors are
shielded. Repair
the short circuit of
harness covered
with shield.
3CHECK INPUT SIGNAL OF ECM.
1) Connect the connectors to ECM and knock
sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 15 (+) — Chassis ground (–):
Is the voltage more than 2 V? Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.(However,
the possibility of
poor contact still
remains.)
NOTE:In this case, repair
the following item:
•Poor contact
of knock sensor
connector
•Poor contact
in ECM connec-
tor
•Poor contact
of coupling con-
nector
Repair poor con-
tact in ECM con-
nector.