SUBARU FORESTER 2004 Service Repair Manual

EN(H4DOTC)-218
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OPERATION OF STARTER MOTOR.Does the starter motor operate
when ignition switch to ON?Repair battery
short circuit in
starter motor cir-
cuit.After repair,
replace the ECM.
<Ref. to
FU(H4DOTC)-50,
Engine Control
Module (ECM).>Check starter
motor circuit. <Ref.
to EN(H4DOTC)-
60, STARTER
MOTOR CIR-
CUIT, Diagnostics
for Engine Start-
ing Failure.>

EN(H4DOTC)-219
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BL:DTC P0519 IDLE CONTROL SYSTEM MALFUNCTION (FAIL-SAFE)
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Engine keeps running at higher revolution than specified idling revolution.
 Fuel is cut according to fail-safe function.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOTC)-47, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)-40, Inspection Mode.>.
WIRING DIAGRAM:
EN-02339
BATTERY MAIN RELAY
EE
7 6
4
5
3
2
1RHD
RHDLHD LHD
27
IDLE
AIR CONTROL
SOLENOID
VALVE
1
3
E7
B47
B4734
12
56
F44
12345678
B134
F44B61
B134
ECM
2
1
RHD
RHD
LHD LHD
B100
F2
F60B21
E3
15
SBF-5
: LHD : RHD
F60
B22 : LHD
: RHD
E7
123
125678
131415169101112
34
17181920
123
4
56
78
9
1011 12
1314 15 16
F74
F61
B21 : LHD
: RHDRHD RHD
E3
B2212
LHD
LHD
12
E2
F61
F74
B200
34
128910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 7
F2
1234 5678910 11 12 13 14 15 16 17 18 19 20
E2
: LHD : RHD
20
56 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31

EN(H4DOTC)-220
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)”. <Ref. to
EN(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>
N
OTE:
In this case, it is
not necessary to
inspect DTC
P0519.Go to step 2.
2 CHECK AIR INTAKE SYSTEM.
1) Turn the ignition switch to ON.
2) Start and idle the engine.
3) Check the following items:
 Loose installation of intake manifold, idle air
control solenoid valve and throttle body
 Cracks of intake manifold gasket, idle air
control solenoid valve gasket and throttle body
gasket
 Disconnections of vacuum hosesIs there any fault in air intake
system?Repair air suction
and leaks.Go to step 3.
3 CHECK THROTTLE CABLE.Does the throttle cable have
play for adjustment?Go to step 4.Adjust throttle
cable. <Ref. to
SP(H4SO)-9,
INSTALLATION,
Accelerator Con-
trol Cable.>
4 CHECK AIR BY-PASS LINE.
1) Turn the ignition switch to OFF.
2) Remove the idle air control solenoid valve
from the throttle body. <Ref. to FU(H4DOTC)-
37, Idle Air Control Solenoid Valve.>
3) Confirm that there are no foreign particles
in by-pass air line.Are foreign particles in by-pass
air line?Remove foreign
particles from by-
pass air line.Replace the idle
air control solenoid
valve. <Ref. to
FU(H4DOTC)-37,
Idle Air Control
Solenoid Valve.>

EN(H4DOTC)-221
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BM:DTC P0545 EXHAUST GAS TEMPERATURE SENSOR CIRCUIT LOW -
BANK 1
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Hard to start
 Erroneous idling
 Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOTC)-47, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)-40, Inspection Mode.>.
WIRING DIAGRAM:
EN-02340
B122
1*
B136 ECM
35 24
B279 EXHAUST
TEMPERATURE
SENSOR1
2
B279
12
B136
LHD : 7
RHD : 6*
B122
12345678
56
782 1
94 310
24 22 23 2511 12 13
1415
26 27
2816
17 18 19 20 21
33 34 29
32 30
31 35

EN(H4DOTC)-222
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of exhaust temperature sen-
sor signal using Subaru Select Monitor or
OBD-II general scan tool.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. <Ref. to EN(H4DOTC)-
33, Subaru Select Monitor.>
 OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is engine coolant temperature
more than 1200°C (2192°F)?Go to step 2.Repair the poor
contact.
N
OTE:
In this case repair
the following:
 Poor contact of
exhaust tempera-
ture sensor
 Poor contact in
ECM
 Poor contact in
joint connector
2 CHECK HARNESS BETWEEN EXHAUST
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from exhaust
temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of exhaust temperature sen-
sor signal using Subaru Select Monitor or
OBD-II general scan tool.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. <Ref. to EN(H4DOTC)-
33, Subaru Select Monitor.>
 OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the temperature less than
372°C (702°F)?Replace the
exhaust tempera-
ture sensor. <Ref.
to FU(H4DOTC)-
49, Exhaust Tem-
perature Sensor.>Repair ground
short circuit in har-
ness between
exhaust tempera-
ture sensor and
ECM connector.

EN(H4DOTC)-223
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BN:DTC P0546 EXHAUST GAS TEMPERATURE SENSOR HIGH - BANK 1
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Hard to start
 Erroneous idling
 Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOTC)-47, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)-40, Inspection Mode.>.
WIRING DIAGRAM:
EN-02340
B122
1*
B136 ECM
35 24
B279 EXHAUST
TEMPERATURE
SENSOR1
2
B279
12
B136
LHD : 7
RHD : 6*
B122
12345678
56
782 1
94 310
24 22 23 2511 12 13
1415
26 27
2816
17 18 19 20 21
33 34 29
32 30
31 35

EN(H4DOTC)-224
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of exhaust temperature sen-
sor signal using Subaru Select Monitor or
OBD-II general scan tool.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. <Ref. to EN(H4DOTC)-
33, Subaru Select Monitor.>
 OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the temperature less than
372°C (702°F)?Go to step 2.Repair the poor
contact.
N
OTE:
In this case repair
the following:
 Poor contact of
exhaust tempera-
ture sensor
 Poor contact in
ECM
 Poor contact in
joint connector
2 CHECK HARNESS BETWEEN EXHAUST
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from exhaust
temperature sensor.
3) Measure the voltage between exhaust tem-
perature sensor connector and engine ground.
Connector & terminal
(B279) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and exhaust
temperature sen-
sor connector.Go to step 3.
3 CHECK HARNESS BETWEEN EXHAUST
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between exhaust tem-
perature sensor connector and engine ground.
Connector & terminal
(B279) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and exhaust
temperature sen-
sor connector.Go to step 4.
4 CHECK HARNESS BETWEEN EXHAUST
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
Measure the voltage between exhaust temper-
ature sensor connector and engine ground.
Connector & terminal
(B279) No. 1 (+) — Engine ground (
−):Is the voltage more than 4 V? Go to step 5.Repair the har-
ness and connec-
tor.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and exhaust
temperature sen-
sor connector
 Poor contact of
exhaust tempera-
ture sensor con-
nector
 Poor contact in
ECM connector.
 Poor contact in
joint connector

EN(H4DOTC)-225
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BO:DTC P0558 GENERATOR CIRCUIT LOW INPUT
NOTE:
Refer to DTC P0559 for diagnostic procedure. <Ref. to EN(H4DOTC)-226, DTC P0559 GENERATOR CIR-
CUIT HIGH INPUT, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
5 CHECK HARNESS BETWEEN EXHAUST
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between exhaust temperature sensor connec-
tor and engine ground.
Connector & terminal
(B279) No. 2 — Engine ground:Is the resistance less than 5
Ω?Replace the
exhaust tempera-
ture sensor. <Ref.
to FU(H4DOTC)-
49, Exhaust Tem-
perature Sensor.>Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and exhaust
temperature sen-
sor connector
 Poor contact of
exhaust tempera-
ture sensor con-
nector
 Poor contact in
ECM connector.
 Poor contact in
joint connector Step Check Yes No

EN(H4DOTC)-226
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BP:DTC P0559 GENERATOR CIRCUIT HIGH INPUT
DTC DETECTING CONDITION:
Immediately at fault recognition
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOTC)-47, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)-40, Inspection Mode.>.
WIRING DIAGRAM:
EN-02341
B100
B134
F2
LHD : 4
RHD : 6
F26
B134
F26 ECM
GENERATOR
22
*
*
3
12
789 56 3
410 11 1219 20 21
29 30 31 13 14 15 1617
27 2818
22 23 24 25 26
123
F2
F2: LHD
: RHD
1234 5678910 11 12 13 14 15 16 17 18 19 20
2345 678911 12 13 14 17 18 19 201101516

EN(H4DOTC)-227
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN GENERATOR
AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from generator
and ECM.
3) Measure the resistance of harness
between generator connector and engine
ground.
Connector & terminal
(F26) No. 3 — Engine ground:Is the resistance more than 1
MΩ?Go to step 2.Repair ground
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
2 CHECK HARNESS BETWEEN GENERATOR
AND ECM CONNECTOR.
Measure the resistance of harness between
ECM and generator.
Connector & terminal
(B134) No. 22 — (F26) No. 3:Is the resistance less than 1
Ω?Repair poor con-
tact connector.Repair open circuit
in harness
between ECM and
generator connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and genera-
tor connector
 Poor contact in
coupling connector