2004 SUBARU FORESTER sensor

EN(H4SO)-157
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Measure the resistance of harness
between camshaft position sensor connector
and engine ground.
Connector & terminal
(E15) No. 1 — Engine ground:Is the resistance more than
100 kΩ?Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor and ECM
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorGo to step 2.
2 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
Measure the resistance of harness between
camshaft position sensor connector and
engine ground.
Connector & terminal
(E15) No. 1 — Engine ground:Is the resistance less than 10
Ω?Repair ground
short circuit in har-
ness between
camshaft position
sensor and ECM
connector.
N
OTE:
The harness be-
tween both connec-
tors are shielded.
Repair ground short
circuit in harness to-
gether with shield.Go to step 3.
3 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
Measure the resistance of harness between
camshaft position sensor connector and
engine ground.
Connector & terminal
(E15) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 4.Repair harness
and connector.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor and ECM
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
4 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 5.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
5 CHECK CAMSHAFT POSITION SENSOR.
1) Remove the camshaft position sensor.
2) Measure the resistance between connector
terminals of camshaft position sensor.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Repair poor con-
tact in camshaft
position sensor
connector.Replace the cam-
shaft position sen-
sor. FU(H4SO)-27,
Camshaft Position
Sensor.>

EN(H4SO)-158
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AL:DTC P0341 CAMSHAFT POSITION SENSOR “A” CIRCUIT RANGE/PERFOR-
MANCE (BANK 1 OR SINGLE SENSOR)
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Engine stalls
 Failure of engine to start
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-00274
B22
E15
12
125678
131415169101112
34
17181920
12
2018
1828
B22
E3
E15
B135ECM CAMSHAFT
POSITION
SENSOR
7
B135
567
82 1
94
310
24 22 23 251112131415
26 27
281617181920 21

EN(H4SO)-159
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 HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Measure the resistance of harness
between camshaft position sensor connector
and engine ground.
Connector & terminal
(E15) No. 1 — Engine ground:Is the resistance more than
100 kΩ?Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor and ECM
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorGo to step 3.
3 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
Measure the resistance of harness between
camshaft position sensor connector and
engine ground.
Connector & terminal
(E15) No. 1 — Engine ground:Is the resistance less than 10
Ω?Repair ground
short circuit in har-
ness between
camshaft position
sensor and ECM
connector.
N
OTE:
The harness be-
tween both con-
nectors are
shielded. Repair
ground short circuit
in harness togeth-
er with shield.Go to step 4.
4 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
Measure the resistance of harness between
camshaft position sensor connector and
engine ground.
Connector & terminal
(E15) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 5.Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor and ECM
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 6.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
6 CHECK CAMSHAFT POSITION SENSOR.
1) Remove the camshaft position sensor.
2) Measure the resistance between connector
terminals of camshaft position sensor.
Te r m i n a l
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Go to step 7.Replace the cam-
shaft position sen-
sor. FU(H4SO)-27,
Camshaft Position
Sensor.>

EN(H4SO)-160
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.
Turn the ignition switch to OFF.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 8.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
8 CHECK CAMSHAFT SPROCKET.
Remove the front belt cover. ME(H4SO)-47, Timing Belt Cover.>Are cam sprocket teeth
cracked or damaged?Replace the cam
sprocket. ME(H4SO)-53,
Cam Sprocket.>Go to step 9.
9 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the camshaft using ST, and align align-
ment mark on cam sprocket with alignment
mark on timing belt cover LH.
ST 499207100 CAM SPROCKET WRENCHIs the timing belt dislocated
from its proper position?Repair installation
condition of timing
belt. ME(H4SO)-48,
Timing Belt.>Replace the cam-
shaft position sen-
sor. FU(H4SO)-27,
Camshaft Position
Sensor.> Step Check Yes No

EN(H4SO)-162
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 CURRENT DATA.
1) Start the engine.
2) Read the data of intake manifold absolute
pressure sensor signal using Subaru Select
Monitor or OBD-II scan tool.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.>
 OBD-II scan tool
For detailed operation procedures, refer to the
OBD-II Scan Tool Instruction Manual.Is the value more than 53.3
kPa (400 mmHg, 15.75 inHg)?Make sure that the
EGR valve, mani-
fold absolute pres-
sure sensor and
throttle body are
tightened firmly.Go to step 3.
3 CHECK THE POWER SUPPLY OF EGR
VALVE.
1) Disconnect the connector from EGR valve.
2) Turn the ignition switch to ON.
3) Measure the voltage between EGR valve
and engine ground.
Connector & terminal
(E18) No. 2 — Engine ground:
(E18) No. 5 — Engine ground:Is the voltage more than 10 V? Go to step 4.Repair open circuit
in harness
between main
relay and EGR
valve connector.
4 CHECK EGR VALVE.
Measure the resistance between EGR valve
terminals.
N
OTE:
Make sure there is no foreign material between
EGR valve and valve seat.
Te r m i n a l s
No. 1 — No. 2:
No. 3 — No. 2:
No. 4 — No. 5:
No. 6 — No. 5:Is the resistance 20 — 30 Ω? Go to step 5.Replace the EGR
valve. FU(H4SO)-34,
EGR Valve.>
5 OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the connector to ECM and EGR
valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 15 (+) — Chassis ground (
−):
(B134) No. 16 (+) — Chassis ground (
−):
(B134) No. 17 (+) — Chassis ground (
−):
(B134) No. 18 (+) — Chassis ground (
−):Is the voltage 0 — 10 V? Repair poor con-
tact portion in
ECM connector.Go to step 6.

EN(H4SO)-164
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AN:DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK
1)
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 Engine stalls
 Idle mixture is out of specifications.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02391
B18
T6
3412
56
B47F44
12345678
T5B136
B137 B135
BATTERY
REAR
OXYGEN
SENSORFRONT OXYGEN
(A/F) SENSORMAIN RELAYSBF-5
B61 F44
B47
T6
T5
B19B18 1 2 3 5 6
4
E
7
B122
B19B14D15C43
4
2B23C13C22C6C17
1
8
1
B135ECM
B136 B :
C :
B137 D :
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
4
1
53
2618 15 167891011
17 19
20121314
567
82 1
94
310
24 22 23 251112131415
26 27
281617181920 21
LHD
LHD
RHD
RHD
4
1
B122
LHDLHD
RHDRHD
4
1 23
3
4
21
1234
3412
B122 : LHD
B122 : RHD
123456781234
B :C :
D :

EN(H4SO)-165
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 rele-
vant 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.Go to step 2.
2 CHECK EXHAUST SYSTEM.
Check for gas leaks or air suction caused by
loose or dislocated nuts and bolts, and open
hole at exhaust pipes.
NOTE:
Check the following positions.
 Between cylinder head and front exhaust
pipe
 Between front exhaust pipe and front cata-
lytic converter
 Between front catalytic converter and rear
catalytic converterIs there a fault in exhaust sys-
tem?Repair or replace
the exhaust sys-
tem. EX(H4SO)-2, Gen-
eral Description.>Go to step 3.
3 CHECK CATALYTIC CONVERTER.Is there damage at rear face or
front face of catalytic con-
ver ter?Replace catalytic
converter. EC(H4SO)-3,
Front Catalytic
Converter.>Go to step 4.
4 CHECK REAR OXYGEN SENSOR CIRCUIT
MALFUNCTION.
1) Disconnect the connector from rear oxygen
sensor and ECM.
2) Measure the resistance between rear oxy-
gen sensor connector and ECM connector.
Connector & terminal
(T6) No. 3 — (B135) No. 19:Is the resistance less than 1
Ω?Go to step 5.Repair battery
open circuit in har-
ness between
ECM and rear oxy-
gen sensor.
5 CHECK SHIELD WIRE.Is the shield wire opened? Repair the shield
wire.Contact the SUB-
ARU dealer.

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