Subaru Legacy (2005 year). Manual — part 215

EN(H4SO 2.5)(diag)-145

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

CHECK 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 (

−

Is the voltage more than 10 V? Repair the poor

contact in all con-
nectors in fuel
injector circuit.

Repair the har-
ness and connec-
tor.

NOTE:
In this case, repair
the following:
• Open circuit of
harness between
main relay and fuel
injector connector
on faulty cylinders
• Poor contact in
coupling connector
• Poor contact in
main relay connec-
tor
• Poor contact in
fuel injector con-
nector on faulty
cylinders

CHECK 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 (B136) No. 6 (+) — Chassis ground (

−

#2 (B136) No. 5 (+) — Chassis ground (

−

#3 (B136) No. 4 (+) — Chassis ground (

−

#4 (B136) No. 3 (+) — 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. <Ref. to
FU(H4SO 2.5)-37,
Engine Control
Module (ECM).>

Go to step 9.

CHECK FUEL INJECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between fuel injec-
tor terminals on faulty cylinder.

Terminals

No. 1 — No. 2:

Is the resistance less than 1
Ω?

Replace the faulty
fuel injector and
ECM. <Ref. to
FU(H4SO 2.5)-32,
Fuel Injector.>
<Ref. to FU(H4SO
2.5)-37, Engine
Control Module
(ECM).>

Go to step 10.

CHECK 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 11.

CHECK CRANK SPROCKET.
Remove the timing belt cover.

Is the crank sprocket rusted or
does it have broken teeth?

Replace the crank
sprocket. <Ref. to
ME(H4SO 2.0)-50,
Crank Sprocket.>

Go to step 12.

CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the crankshaft to align the alignment mark
on crank sprocket with the alignment mark on
cylinder block.

Is the timing belt dislocated
from its proper position?

Correct the instal-
lation condition of
timing belt. <Ref.
to ME(H4SO 2.0)-
43, Timing Belt.>

Go to step 13.

Step

Check

Yes

EN(H4SO 2.5)(diag)-146

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

CHECK FUEL LEVEL.

Is the fuel gauge indication
higher than the “Lower” level?

Go to step 14.

Replenish fuel so
fuel gauge indica-
tion is higher than
the “Lower” level.
After replenishing
fuel, Go to step 14.

CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1) Perform the clear memory mode using
Subaru Select Monitor.
<Ref. to EN(H4SO 2.5)(diag)-40, Clear Mem-
ory Mode.>
2) Start the engine, and drive the vehicle more
than 10 minutes.

Does the malfunction indicator
light illuminate or blink?

Go to step 16.

Go to step 15.

CHECK CAUSE OF MISFIRE DIAGNOSED.

Has the cause of misfire been
detected while running the
engine? EX. Disconnection of
spark plug cord.

Finish diagnostics
operation, if the
engine has no
abnormality.

Repair the poor
contact.

NOTE:
In this case, repair
the following:
• Poor contact in
ignition coil con-
nector
• Poor contact in
fuel injector con-
nector on faulty
cylinders
• Poor contact in
ECM connector
• Poor contact in
coupling connector

CHECK AIR INTAKE SYSTEM.

Is there any fault in air intake
system?

Repair the air
intake system.

NOTE:
Check the follow-
ing items.
• Are there air
leaks or air suction
caused by loose or
dislocated nuts
and bolts?
• Are there cracks
or any disconnec-
tion of hoses?

Go to step 17.

CHECK MISFIRE SYMPTOM.
1) Turn the ignition switch to ON.
2) Read the DTC.
• Subaru Select Monitor
<Ref. to EN(H4SO 2.5)(diag)-25, Subaru
Select Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.

NOTE:

Perform diagnosis according to the items listed
below.

Does the Subaru Select Moni-
tor or general scan tool display
only one DTC?

Go to step 22.

Go to step 18.

CHECK ANY OTHER DTC ON DISPLAY.

Are DTC P0301 and P0302
displayed?

Go to step 23.

Go to step 19.

CHECK DTC ON DISPLAY.

Are DTC P0303 and P0304
displayed?

Go to step 24.