2004 SUBARU FORESTER fuel

ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK SPEEDOMETER AND TACHOME- TER OPERATION IN COMBINATION
METER. Does the speedometer and
tachometer operate normally?
Go to step
2.Repair or replace
the combination
meter. 3, Combination
Meter System.>
2 CHECK INPUT SIGNAL FROM ECM. 1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal (B135) No. 25 (+) — Chassis ground (
−): Is the voltage less than 0.12
V?
Go to step
4.Go to step 3.
3 CHECK INPUT SIGNAL FOR ECM (WITH SUBARU SELECT MONITOR).
Read the data of fuel level sensor signal using
Subaru Select Monitor.
N
OTE:
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.> Is the voltage less than 0.12 V
by shaking the ECM harness
and connector?
Repair the poor
contact in ECM
connector.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
NOTE:
In this case repair
the following:
 Poor contact in
combination meter
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
4 CHECK INPUT VOLTAGE OF ECM. 1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM connector and chassis ground.Connector & terminal
(B135) No. 25 (+) — Chassis ground (
−): Is the voltage more than 0.12
V?
Go to step
5.Go to step 6.
5 CHECK HARNESS BETWEEN ECM AND COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from connector
(i10) and ECM connector.
3) Measure the resistance between ECM and
chassis ground.Connector & terminal (B135) No. 25 — Chassis ground: Is the resistance more than 1
M
Ω? Go to step
7.Repair the ground
short in harness
between ECM and
combination meter
connector.
6 CHECK HARNESS BETWEEN ECM AND COMBINATION METER.
Measure the resistance between ECM and
combination meter connector.Connector & terminal (B135) No. 25 — (i11) No. 1: Is the resistance less than 10
Ω
? Repair or replace
the combination
meter. 3, Combination
Meter System.>Repair open circuit
between ECM and
combination meter
connector.
NOTE:
In this case repair
the following:
Poor contact in
coupling connector
EN(H4SO)-174

EN(H4SO)-175
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FUEL TANK CORD.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel sub
level sensor.
3) Measure the resistance between fuel sub
level sensor and chassis ground.
Connector & terminal
(R59) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 8.Repair ground
short circuit in fuel
tank cord.
8 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel pump
assembly.
2) Measure the resistance between fuel pump
assembly and chassis ground.
Connector & terminal
(R59) No. 2 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 9.Repair ground
short circuit in fuel
tank cord.
9 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4SO)-57, Fuel Level Sensor.>
2) Measure the resistance between fuel level
sensor and terminals with its float set to the full
position.
Te r m i n a l s
No. 3 — No. 5:Is the resistance 0.5 — 2.5 Ω? Go to step 10.Replace the fuel
level sensor.
10 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4SO)-58, Fuel Sub Level Sensor.>
2) Measure the resistance between fuel sub
level sensor and terminals with its float set to
the full position.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 0.5 — 2.5 Ω? Repair poor con-
tact in harness
between ECM and
combination meter
connector.Replace the fuel
sub level sensor. Step Check Yes No

EN(H4SO)-176
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AS:DTC P0463 FUEL LEVEL SENSOR CIRCUIT HIGH 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

EN(H4SO)-177
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.Does the speedometer and
tachometer operate normally?Go to step 2.Repair or replace
the combination
meter. 3, Combination
Meter System.>
2 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 25 (+) — Chassis ground (
−):Is the voltage more than 4.75
V?Go to step 3.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
N
OTE:
In this case repair
the following:
 Poor contact in
fuel pump connec-
tor
 Poor contact in
coupling connector
3 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the combination meter connec-
tor (i11) and ECM connector.
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM and chassis ground.
Connector & terminal
(B135) No. 25 (+) — Chassis ground (
−):Is the voltage more than 4.75
V?Go to step 4.Repair battery
short circuit
between ECM and
combination meter
connector.
4 CHECK HARNESS BETWEEN ECM AND
FUEL TANK CORD.
1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Measure the resistance between ECM and
fuel tank cord.
Connector & terminal
(B135) No. 25 — (R15) No. 2:Is the resistance less than 5
Ω?Go to step 5.Repair open circuit
between ECM and
fuel tank cord.
5 CHECK HARNESS BETWEEN FUEL TANK
CORD AND CHASSIS GROUND.
Measure the resistance between fuel tank cord
and chassis ground.
Connector & terminal
(R15) No. 3 — Chassis ground:Is the resistance less than 5
Ω?Go to step 6.Repair open circuit
between fuel tank
cord and chassis
ground.
N
OTE:
In this case repair
the following:
Poor contact in
coupling connec-
tor.
6 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel level
sensor.
2) Measure the resistance between fuel level
sensor and coupler connector.
Connector & terminal
(R57) No. 3 — (R58) No. 5:Is the resistance less than 10
Ω?Go to step 7.Repair open circuit
between coupling
connector and fuel
level sensor.

EN(H4SO)-178
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel sub
level sensor.
2) Measure the resistance between fuel level
sensor and fuel sub level sensor.
Connector & terminal
(R58) No. 3 — (R59) No. 2:Is the resistance less than 10
Ω?Go to step 8.Repair open circuit
between fuel level
sensor and fuel
sub level sensor.
8 CHECK FUEL TANK CORD.
Measure the resistance between fuel level sen-
sor and coupler connector.
Connector & terminal
(R57) No. 2 — (R59) No. 1:Is the resistance less than 10
Ω?Go to step 9.Repair open circuit
between coupling
connector and fuel
level sensor.
9 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4SO)-57, Fuel Level Sensor.>
2) While moving the fuel level sensor float up
and down, measure resistance between fuel
level sensor terminals.
Te r m i n a l s
No. 3 — No. 5:Is the resistance more than
54.5 Ω?Replace the fuel
level sensor. to FU(H4SO)-57,
Fuel Level Sen-
sor.>Go to step 10.
10 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4SO)-58, Fuel Sub Level Sensor.>
2) While moving the fuel sub level sensor float
up and down, measure resistance between
fuel sub level sensor terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance more than
41.5 Ω?Replace the fuel
sub level sensor.
FU(H4SO)-58,
Fuel Sub Level
Sensor.>Replace the com-
bination meter.
Combination
Meter Assembly.> Step Check Yes No

EN(H4SO)-179
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AT:DTC P0464 FUEL LEVEL SENSOR CIRCUIT INTERMITTENT
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)-180
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
P0462 or P0463
using “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>Go to step 2.
2 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4SO)-55, Fuel Pump.>
2) While moving the fuel level sensor float up
and down, make sure that the resistance
between fuel level sensor terminals changes
smoothly.
Te r m i n a l s
No. 3 — No. 5:Does the resistance change
slowly?Go to step 3.Replace the fuel
level sensor. to FU(H4SO)-57,
Fuel Level Sen-
sor.>
3 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4SO)-57, Fuel Level Sensor.>
2) While moving the fuel sub level sensor float
up and down, make sure that the resistance
between fuel level sensor terminals changes
smoothly.
Te r m i n a l s
No. 1 — No. 2:Does the resistance change
slowly?Repair poor con-
tact in ECM, com-
bination meter and
coupling connec-
tors.Replace the fuel
sub level sensor.
FU(H4SO)-58,
Fuel Sub Level
Sensor.>

EN(H4SO)-230
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).>Go to step 2.
2 CHECK FRONT (A/F) OXYGEN SENSOR DA-
TA.
1) Start the engine.
2) While observing the Subaru Select Monitor
or OBD-II general scan tool screen, warm-up
the engine until coolant temperature is above
70°C (160°F).
If the engine is already warmed-up, operate at
idle speed for at least 1 minute.
3) Read the data of front oxygen (A/F) sensor
signal at idling using Subaru Select Monitor or
OBD-II general scan tool.
NOTE:
 Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.>
 OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the voltage 0.85 — 1.15 V? Go to step 3.Go to step 4.
3 CHECK FRONT (A/F) OXYGEN SENSOR DA-
TA.
Race the engine at speeds from idling to 5,000
rpm for a total of 5 cycles.
N
OTE:
 Normally the air fuel ratio be rich at racing.
 To increase engine speed to 5,000 rpm,
slowly depress accelerator pedal, taking
approximately 5 seconds, and quickly release
accelerator pedal to decrease engine speed.Is the voltage more than 1.1 V? Go to step 6.Go to step 4.
4 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor connector.
3) Measure the resistance between ECM and
front oxygen (A/F) sensor.
Connector & terminal
(B136) No. 13 — (B18) No. 1:
(B136) No. 22 — (B18) No. 2:Is the resistance less than 5
Ω?Go to step 5.Repair open circuit
between ECM and
front oxygen (A/F)
sensor.
5 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR.
Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 13 — Chassis ground:
(B136) No. 22 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 6.Repair ground
short circuit
between ECM and
front oxygen (A/F)
sensor.