2004 SUBARU FORESTER fuel

EN(H4SO)-143
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Inspect the DTC
using “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>
N
OTE:
In this case, it is not
necessary to in-
spect DTC P0301,
P0302, P0303 and
P0304.Go to step 2.
2 CHECK OUTPUT SIGNAL FROM 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 (B134) No. 34 (+) — Chassis ground (
−):
#2 (B134) No. 23 (+) — Chassis ground (
−):
#3 (B134) No. 22 (+) — Chassis ground (
−):
#4 (B134) No. 8 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 7.Go to step 3.
3 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 cylinder.
3) Measure the voltage 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:Is the resistance more than 1
MΩ?Go to step 4.Repair ground
short circuit in har-
ness between fuel
injector and ECM
connector.
4 CHECK 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 (B134) No. 34 — (E5) No. 1:
#2 (B134) No. 23 — (E16) No. 1:
#3 (B134) No. 22 — (E6) No. 1:
#4 (B134) No. 8 — (E17) No. 1:Is the resistance less than 1
Ω?Go to step 5.Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and fuel
injector connector
 Poor contact in
coupling connector
5 CHECK 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 5 — 20 Ω? Go to step 6.Replace the faulty
fuel injector. to FU(H4SO)-35,
Fuel Injector.>

EN(H4SO)-144
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 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 poor con-
tact in all connec-
tors in fuel injector
circuit.Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
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
7 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 cylinder.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM con-
nector and chassis ground on faulty cylinders.
Connector & terminal
#1 (B134) No. 34 (+) — Chassis ground (
−):
#2 (B134) No. 23 (+) — Chassis ground (
−):
#3 (B134) No. 22 (+) — Chassis ground (
−):
#4 (B134) No. 8 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and fuel
injector. After
repair, replace the
ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 8.
8 CHECK 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 to FU(H4SO)-35,
Fuel Injector.> and
ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 9.
9 CHECK INSTALLATION OF CAMSHAFT PO-
SITION SENSOR/CRANKSHAFT POSITION
SENSOR.Is the installation of camshaft
position sensor or crankshaft
position sensor loosened?Tighten camshaft
position sensor or
crankshaft posi-
tion sensor.Go to step 10.
10 CHECK CRANK SPROCKET.
Remove the timing belt cover.Is the crank sprocket rusted or
does it have broken teeth?Replace the crank
sprocket. ME(H4SO)-55,
Crank Sprocket.>Go to step 11.
11 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the crankshaft using ST, and align align-
ment mark on crank sprocket with alignment
mark on cylinder block.
ST 499987500 CRANKSHAFT SOCKETIs the timing belt dislocated
from its proper position?Repair installation
condition of timing
belt. ME(H4SO)-48,
Timing Belt.>Go to step 12.
12 CHECK FUEL LEVEL.Is the fuel meter indication
higher than the “Lower” level?Go to step 13.Replenish fuel so
fuel meter indica-
tion is higher than
the “Lower” level.
After replenishing
fuel, Go to step 13. Step Check Yes No

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

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

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

EN(H4SO)-171
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AQ:DTC P0461 FUEL LEVEL SENSOR CIRCUIT RANGE/PERFORMANCE
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
R59R58
R57
R15
B38i3
B98R2
B10
C1 B9
25
3
5
i10 B :
i11 C :B135ECM
EE
E
IGNITION
SWITCH
SBF-4SBF-14
COMBINATION
METERSBF-1
B72
14
FUEL SUB
LEVEL SENSOR
FUEL SUB
METER UNIT
FUEL LEVEL
SENSOR1
2
BATTERY
B38
i3
B38
i320E2
B211528
LHD
LHDRHD
RHDLHD
LHDRHD
RHD
2
16
B38i3
LHD
LHDRHD
RHD
4 3
B99R3
B38i3
LHD
LHDRHD
RHD
16
5
B37i2
EN-02393
2
3
B135
B72
R15R59i10R58
3412
13
456212123456789101112131415161718192021222324252627282930
567
82 1
94
310
24 22 23 251112131415
26 27
281617181920 21
219
32
1234 5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25
i3
B99
12345678
i11
34 12 8567910
B37
34 12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
B:
C:
B98
123
4
56
78
9
1011 12
1314 15 16
B21

EN(H4SO)-172
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Inspect DTC using
“List of Diagnostic
Trouble Code
(DTC)”. EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>
N
OTE:
In this case, it is not
necessary to in-
spect DTC P0420.Replace the fuel
level sensor. to FU(H4SO)-57,
Fuel Level Sen-
sor.> and fuel sub
level sensor. to FU(H4SO)-58,
Fuel Sub Level
Sensor.>

EN(H4SO)-173
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AR:DTC P0462 FUEL LEVEL SENSOR CIRCUIT LOW INPUT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
R59R58
R57
R15
B38i3
B98R2
B10
C1 B9
25
3
5
i10 B :
i11 C :B135ECM
EE
E
IGNITION
SWITCH
SBF-4SBF-14
COMBINATION
METERSBF-1
B72
14
FUEL SUB
LEVEL SENSOR
FUEL SUB
METER UNIT
FUEL LEVEL
SENSOR1
2
BATTERY
B38
i3
B38
i320E2
B211528
LHD
LHDRHD
RHDLHD
LHDRHD
RHD
2
16
B38i3
LHD
LHDRHD
RHD
4 3
B99R3
B38i3
LHD
LHDRHD
RHD
16
5
B37i2
EN-02393
2
3
B135
B72
R15R59i10R58
3412
13
456212123456789101112131415161718192021222324252627282930
567
82 1
94
310
24 22 23 251112131415
26 27
281617181920 21
219
32
1234 5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25
i3
B99
12345678
i11
34 12 8567910
B37
34 12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
B:
C:
B98
123
4
56
78
9
1011 12
1314 15 16
B21