2004 SUBARU FORESTER engine

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. 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. 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. 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 ERATION, Clear Memory Mode.> and 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. 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 ERATION, Clear Memory Mode.> and 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)”. 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. 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 ERATION, Clear Memory Mode.> and 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. 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 ERATION, Clear Memory Mode.> and 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