Page 1113 of 2870
EN(H4SO)-15
ENGINE (DIAGNOSTIC)
Electrical Component Location
SOLENOID VALVE, EMISSION CONTROL SYSTEM PARTS AND IGNITION SYSTEM PARTS
EN-02399
(2)(3)
(1)(4)
(1) Idle air control solenoid valve (3) Ignition coil & ignitor ASSY (4) EGR Valve
(2) Purge control solenoid valve
(1)
EN-00249EN-00250
(2)
Page 1162 of 2870
EN(H4SO)-64
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
D: IGNITION CONTROL SYSTEM
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode
ERATION, Clear Memory Mode.> and Inspection Mode
tion Mode.>.
WIRING DIAGRAM:
EN-00263
BATTERY
1 IGNITION
SWITCHSBF-44
A32
B21
E2
B134
1234567891011121314151617181920212223242526272829303132333435
B72
34
12
SBF-1No.11
54146
1234
B136 C:
B134 A:ECM
A33C26
34
12
IGNITOR
&
IGNITOR COIL ASSY
1234
E12B21
123
4
56
78
9
1011 12
1314 15 16
B72
B136
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
E12
C:
A:
Page 1163 of 2870

EN(H4SO)-65
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
Step Check Yes No
1 CHECK IGNITION SYSTEM FOR SPARKS.
1) Remove the plug cord cap from each spark
plug.
2) Install the new spark plug on plug cord cap.
CAUTION:
Do not remove the spark plug from engine.
3) Contact the spark plug’s thread portion on
engine.
4) While opening the throttle valve fully, crank
the engine to check that spark occurs at each
cylinder.Does spark occur at each cyl-
inder?Check fuel pump
system.
EN(H4SO)-67,
FUEL PUMP CIR-
CUIT, Diagnostics
for Engine Start-
ing Failure.>Go to step 2.
2 CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL & IGNITOR ASSY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil
& ignitor ASSY.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
ignition coil & ignitor ASSY connector and
engine ground.
Connector & terminal
(E12) No. 2 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 3.Repair harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ignition coil & igni-
tor ASSY, and
main relay connec-
tor
Poor contact in
coupling connector
Blown out fuse
3 CHECK HARNESS OF IGNITION COIL & IG-
NITOR ASSY GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ignition
coil & ignitor ASSY connector and engine
ground.
Connector & terminal
(E12) No. 3 — Engine ground:Is the resistance less than 5
Ω?Go to step 4.Repair harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ignition coil & igni-
tor ASSY connec-
tor and engine
ground terminal
4 CHECK IGNITION COIL & IGNITOR ASSY.
1) Remove the spark plug cords.
2) Measure the resistance between spark
plug cord contact portions to check secondary
coil.
Te r m i n a l s
No. 1 — No. 2:
No. 3 — No. 4:Is the resistance 10 — 15 kΩ? Go to step 5.Replace the igni-
tion coil & ignitor
ASSY.
IG(H4SO)-8, Igni-
tion Coil & Ignitor
Assembly.>
5 CHECK INPUT SIGNAL FOR IGNITION COIL
& IGNITOR ASSY.
1) Connect the connector to ignition coil &
ignitor ASSY.
2) Check if voltage varies synchronously with
engine speed when cranking, while monitoring
voltage between ignition coil & ignitor ASSY
connector and engine ground.
Connector & terminal
(E12) No. 1 (+) — Engine ground (
−):
(E12) No. 4 (+) — Engine ground (
−):Does the voltage vary more
than 10 V?Go to step 6.Replace the igni-
tion coil & ignitor
ASSY.
IG(H4SO)-8, Igni-
tion Coil & Ignitor
Assembly.>
Page 1164 of 2870

EN(H4SO)-66
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
6 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connector from ignition coil
& ignitor ASSY.
4) Measure the resistance of harness
between ECM and ignition coil & ignitor ASSY
connector.
Connector & terminal
(B134) No. 32 — (E12) No. 1:
(B134) No. 32 — (E12) No. 4:Is the resistance less than 1
Ω?Go to step 7.Repair harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ECM and ignition
coil & ignitor ASSY
connector.
Poor contact in
coupling connector
7 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
Measure the resistance of harness between
ECM and engine ground.
Connector & terminal:
(B134) No. 32 — Engine ground:Is the resistance more than 1
MΩ?Go to step 8.Repair ground
short circuit in har-
ness between
ECM and ignition
coil & ignitor ASSY
connector.
8 CHECK POOR CONTACT.
Check poor contact in ECM connector. Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Check fuel pump
circuit.
EN(H4SO)-67,
FUEL PUMP CIR-
CUIT, Diagnostics
for Engine Start-
ing Failure.> Step Check Yes No
Page 1243 of 2870

EN(H4SO)-145
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
13 CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1) Clear the memory using Subaru Select
Monitor.
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 DIAGNOSED.Was the cause of misfire diag-
nosed when the engine is run-
ning? Ex. Removed spark plug
cord, etc.Finish diagnostics
operation, if the
engine has no
abnormality.1. Repair the poor
contact.
N
OTE:
In this case repair
the following:
Poor contact in
ignitor connector
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
2. If there is no
poor contact,
check the following
items and contact
SUBARU dealer.
Fuel condi-
tion
Contained
additive
Plug condi-
tion
Plug cord
condition
Engine oil
condition
15 CHECK AIR INTAKE SYSTEM.Is there any fault in air intake
system?Repair air intake
system.
N
OTE:
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 16. Step Check Yes No
Page 1244 of 2870

EN(H4SO)-146
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
16 CHECK MISFIRE SYMPTOM.
1) Turn the ignition switch to ON.
2) READ DTC.
Subaru Select Monitor
tor.>
OBD-II scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
N
OTE:
Perform diagnosis according to the items listed
below.Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate a DTC?Go to step 21.Go to step 17.
17 CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0301 and P0302 dis-
played?Go to step 22.Go to step 18.
18 CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0303 and P0304 dis-
played?Go to step 23.Go to step 19.
19 CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0301 and P0303 dis-
played?Go to step 24.Go to step 20.
20 CHECK ANY OTHER DTC ON DISPLAY.Is DTC P0302 and P0304 dis-
played?Go to step 25.Go to step 26.
21 ONLY ONE CYLINDER.Is there a fault in that cylinder? Repair or replace
the faulty par t.
N
OTE:
Check the follow-
ing items:
Spark plug
Spark plug cord
Fuel injector
Compression
ratioGo to DTC P0171.
EN(H4SO)-138,
DTC P0171 SYS-
TEM TOO LEAN
(BANK 1), Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).>
22 GROUP OF #1 AND #2 CYLINDERS.Are there faults in #1 and #2
cylinders?Repair or replace
the faulty par t.
N
OTE:
Check the fol-
lowing items:
Spark plug
Fuel injector
Ignition coil
Compres-
sion ratio
If no abnormal is
discovered, check
for “IGNITION
CONTROL SYS-
TEM” of #1 and #2
cylinders side.
EN(H4SO)-64,
IGNITION CON-
TROL SYSTEM,
Diagnostics for
Engine Starting
Fa il u r e. >Go to DTC P0171.
EN(H4SO)-138,
DTC P0171 SYS-
TEM TOO LEAN
(BANK 1), Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).> Step Check Yes No
Page 1245 of 2870

EN(H4SO)-147
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
23 GROUP OF #3 AND #4 CYLINDERS.Are there faults in #3 and #4
cylinders?Repair or replace
the faulty par t.
N
OTE:
Check the fol-
lowing items:
Spark plug
Fuel injector
Ignition coil
If no abnormal is
discovered, check
for “16. D: IGNI-
TION CONTROL
SYSTEM” of #3
and #4 cylinders
side.
EN(H4SO)-64,
IGNITION CON-
TROL SYSTEM,
Diagnostics for
Engine Starting
Fa il u r e. >Go to DTC P0171.
EN(H4SO)-138,
DTC P0171 SYS-
TEM TOO LEAN
(BANK 1), Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).>
24 GROUP OF #1 AND #3 CYLINDERS.Are there faults in #1 and #3
cylinders?Repair or replace
the faulty par t.
N
OTE:
Check the follow-
ing items:
Spark plug
Fuel injector
Skipping timing
belt teethGo to DTC P0171.
EN(H4SO)-138,
DTC P0171 SYS-
TEM TOO LEAN
(BANK 1), Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).>
25 GROUP OF #2 AND #4 CYLINDERS.Are there faults in #2 and #4
cylinders?Repair or replace
the faulty par t.
NOTE:
Check the follow-
ing items:
Spark plug
Fuel injector
Compression
ratio
Skipping timing
belt teethGo to DTC P0171.
EN(H4SO)-138,
DTC P0171 SYS-
TEM TOO LEAN
(BANK 1), Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).>
26 CYLINDER AT RANDOM.Is the engine idle rough? Go to DTC P0171.
EN(H4SO)-138,
DTC P0171 SYS-
TEM TOO LEAN
(BANK 1), Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).>Repair or replace
the faulty part.
N
OTE:
Check the follow-
ing items:
Spark plug
Fuel injector
Compression
ratio Step Check Yes No
Page 1354 of 2870

EN(H4SO)-256
ENGINE (DIAGNOSTIC)
General Diagnostic Table
*1: Check ignition coil & ignitor ASSY and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure the secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect air leak in air intake system.
*6: Adjust the accelerator cable.
2. AUTOMATIC TRANSMISSION
NOTE:
Check general diagnostics table with non-conformity symptom for automatic transmission.
4AT(H4SO)-2, Basic Diagnostic Procedure.>
6. Surging1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Crankshaft position sensor (*3)
6) Camshaft position sensor (*3)
7) Fuel injection parts (*4)
8) Throttle position sensor
9) Fuel pump and fuel pump relay
7. Spark knock1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor
5) Knock sensor
6) Fuel injection parts (*4)
7) Fuel pump and fuel pump relay
8. After burning in exhaust system1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay Symptom Problem parts