engine SUBARU FORESTER 2004 Service Repair Manual

EN(H4DOTC)-275
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
front oxygen (A/F) sensor.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B134) No. 33 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 2.Repair the ground
short circuit in har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
2 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 26 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the ground
short circuit in har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
3 CHECK OUTPUT SIGNAL FOR ECM.
1) Connect the connector to ECM and front
oxygen (A/F) sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 33 (+) — Chassis ground (
−):Is the voltage more than 4.5 V? Go to step 4.Go to step 5.
4 CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 33 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair the battery
short circuit in har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.After
repair, replace the
ECM. <Ref. to
FU(H4DOTC)-50,
Engine Control
Module (ECM).>Repair the poor
contact in ECM
connector.
5 CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 19 (+) — Chassis ground (
−):Is the voltage more than 4.95
V?Go to step 6.Replace the front
oxygen (A/F) sen-
sor. <Ref. to
FU(H4DOTC)-45,
Front Oxygen (A/
F) Sensor.>
6 CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 26 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair the battery
short circuit in har-
ness between
ECM and front
oxygen (A/F) sen-
sor connector.After
repair, replace the
ECM. <Ref. to
FU(H4DOTC)-50,
Engine Control
Module (ECM).>Repair the poor
contact in ECM
connector.

EN(H4DOTC)-276
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
CP:DTC P1301 MISFIRE DETECTED (HIGH TEMPERATURE EXHAUST GAS)
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 Erroneous idling
 Engine stalls.
 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)-277
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK DTC.
Conduct the troubleshooting for all DTC
P0301, P0302, P0303 and P0304. <Ref. to
EN(H4DOTC)-74, List of Diagnostic Trouble
Code (DTC).>Does failure for repair or
replacement exist?Repair or replace
failure, then
replace the precat-
alytic converter.Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

EN(H4DOTC)-278
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
CQ:DTC P1312 INTAKE AIR TEMPERATURE CIRCUIT RANGE/PERFORMANCE
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-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)-279
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
P1312.Replace the
exhaust tempera-
ture sensor. <Ref.
to FU(H4DOTC)-
49, Exhaust Tem-
perature Sensor.>

EN(H4DOTC)-280
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
CR:DTC P1518 STARTER SWITCH CIRCUIT LOW INPUT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Failure of engine to start
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-02311
BATTERY
INHIBITOR SWITCH
IGNITION
SWITCH
STARTER
MOTOR
SBF-4SBF-1
B72
B72
B14
B137
ECM
EE
1
3
D8
3412
B137
T3B12MT
AT
AT
MT
1112712
PR
N
D3
21
T7
B12
123
8
9
10
4
11
1256
7
T7
123
8910411 1256
7567
82 1
94 310
22 23 11 12 13 14 15
24 25
2616 17
18 19 20 21
27 28 29 30 31

EN(H4DOTC)-281
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
START?Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open or ground
short circuit in har-
ness between
ECM and starter
motor connector.
 Poor contact in
ECM connector.Check starter
motor circuit. <Ref.
to EN(H4DOTC)-
60, STARTER
MOTOR CIR-
CUIT, Diagnostics
for Engine Start-
ing Failure.>

EN(H4DOTC)-282
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
CS:DTC P1544 EXHAUST GAS TEMPERATURE TOO HIGH
DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
 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)-283
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
P1544.Go to step 2.
2 CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following items:
 Loose installation of exhaust manifold
 Cracks or hole of exhaust manifold
 Loose installation of front oxygen (A/F) sen-
sorIs there a fault in exhaust sys-
tem?Repair or replace
failure, then
replace the precat-
alytic converter.Contact the SUB-
ARU dealer.
NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

EN(H4DOTC)-284
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
CT:DTC P1560 BACK-UP VOLTAGE CIRCUIT MALFUNCTION
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:
LHD model
EN-02312
F74
B72
34
12
BATTERYIGNITION
SWITCH MAIN RELAY
SBF-4SBF-1
SBF-5
B72 TO FRONT OXYGEN (A/F) SENSOR
D16 D7
B12
A6
A7
B4
B1
D1
D2
A34B5
D6
B19
D14
No.11
B61F44
B47
B100
F2
E3 F60 1 2 3 5 6 4
ECM
EE
14
B134
B137 B135 A :
B :
C :B136
D :
14
7
3412
56
123
4
56
78
9
1011 12
1314 15 16
F60B47
B137
F2
B100F2
11
10
20
8
9 13
14
3
15
16
B135
F44
567
82 1
94 310
24 22 23 2511 12 13 14 15
26 27
2816 17 18 19
20 21
29 30 31 32 33 34 35
12345678
34
12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 71234 5678910 11 12 13 14 15 16 17 18 19 20
567
82 1
94 310
22 23 11 12 13 14 15
24 25
2616 17
18 19 20 21
27 28 29 30 31
F74 B200
MT
MT
B134
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
B136
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