SUBARU FORESTER 2004 Service Repair Manual

ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
RHD model
EN-02323
B122
MANIFOLD
ABSOLUTE
PRESSURE
SENSOR THROTTLE BODY
3
2
1
35
16
22
ECMB136
E21
E3
B22
2
120
18
16
123
B122B22E21
1
25678
131415169101112
34
17181920
B136
1234567856
78 21
9 4310
2422 23 25
11 12 13
1415
26 27
28 16
17 18 19 20 21 33 34
29
32
30
31 35
EN(H4DOTC)-108

EN(H4DOTC)-109
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 16 (+) — Chassis ground (
−):Is the voltage more than 4.5 V? Go to step 3.Go to step 2.
2 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 16 (+) — Chassis ground (
−):Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with voltage
meter?Repair the poor
contact in ECM
connector.Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.
3 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 22 (+) — Chassis ground (
−):Is the voltage more than 4.5 V? Go to step 4.Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.
4 CHECK HARNESS BETWEEN ECM AND
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the manifold
absolute pressure sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between manifold
absolute pressure sensor connector and
engine ground.
Connector & terminal
(E21) No. 3 (+) — Engine ground (
−):Is the voltage more than 4.5 V? Go to step 5.Repair the open
circuit in harness
between ECM and
manifold absolute
pressure sensor
connector.
5 CHECK HARNESS BETWEEN ECM AND
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM and manifold absolute pressure
sensor connector.
Connector & terminal
(B136) No. 22 — (E21) No. 1:Is the resistance less than 1
Ω?Go to step 6.Repair the open
circuit in harness
between ECM and
manifold absolute
pressure sensor
connector.
6 CHECK HARNESS BETWEEN ECM AND
MANIFOLD ABSOLUTE PRESSURE SEN-
SOR CONNECTOR.
Measure the resistance of harness between
ECM and manifold absolute pressure sensor
connector.
Connector & terminal
(B136) No. 35 — (E21) No. 2:Is the resistance less than 1
Ω?Go to step 7.Repair the open
circuit in harness
between ECM and
manifold absolute
pressure sensor
connector.
7 CHECK POOR CONTACT.
Check poor contact in manifold absolute pres-
sure sensor connector. Is there poor contact in mani-
fold absolute pressure sensor
connector?Repair poor con-
tact in manifold
absolute pressure
sensor connector.Replace the mani-
fold absolute pres-
sure sensor. to FU(H4DOTC)-
36, Manifold Abso-
lute Pressure Sen-
sor.>

EN(H4DOTC)-110
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
N: DTC P0111 INTAKE AIR TEMPERATURE CIRCUIT RANGE/PERFORMANCE
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
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-02324
B122B3
BATTERY
E
B61F44
7LHD
RHD
LHD
RHD
1
B3
MASS AIR FLOW AND INTAKE
AIR TEMPERATURE SENSOR
ECMB136
SBF-5
123453412
56
B47 1
2
*
*
2 4 3 5
311323 3532LHD : 8
RHD : 5
LHD : 1
RHD : 1*1
*2
F44
12345678
MAIN RELAY
B47 1 2 3 5 4 6
12345678
B136 B122
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)-111
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
P0111.Go to step 2.
2 CHECK ENGINE COOLANT.
1) Start the engine and warm-up completely.
2) Measure the engine coolant temperature
using Subaru Select Monitor or OBD-II general
scan tool.
NOTE:
 Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. 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 engine coolant tempera-
ture between 75°C (167°F) and
95°C (203°F)?Replace the mass
air flow and intake
air temperature
sensor. FU(H4DOTC)-35,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>Inspect the DTC
P0125 using “List
of Diagnostic Trou-
ble Code (DTC)”.
EN(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>

EN(H4DOTC)-112
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
O: DTC P0112 INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT
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-02324
B122B3
BATTERY
E
B61F44
7LHD
RHD
LHD
RHD
1
B3
MASS AIR FLOW AND INTAKE
AIR TEMPERATURE SENSOR
ECMB136
SBF-5
123453412
56
B47 1
2
*
*
2 4 3 5
311323 3532LHD : 8
RHD : 5
LHD : 1
RHD : 1*1
*2
F44
12345678
MAIN RELAY
B47 1 2 3 5 4 6
12345678
B136 B122
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)-113
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 intake air temperature
sensor signal using Subaru Select Monitor or
the 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”. 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 55°C (131°F)?Go to step 2.Repair the poor
contact.
N
OTE:
In this case repair
the following:
 Poor contact in
mass air flow and
intake air tempera-
ture sensor
 Poor contact in
ECM
 Poor contact in
joint connector
2 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air
flow and intake air temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of intake air temperature
sensor signal using Subaru Select Monitor or
the 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”. 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 value less than −36°C
(−33°F)?Replace the mass
air flow and intake
air temperature
sensor. FU(H4DOTC)-35,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>Repair ground
short circuit in har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.

EN(H4DOTC)-114
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
P: DTC P0113 INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT
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-02324
B122B3
BATTERY
E
B61F44
7LHD
RHD
LHD
RHD
1
B3
MASS AIR FLOW AND INTAKE
AIR TEMPERATURE SENSOR
ECMB136
SBF-5
123453412
56
B47 1
2
*
*
2 4 3 5
311323 3532LHD : 8
RHD : 5
LHD : 1
RHD : 1*1
*2
F44
12345678
MAIN RELAY
B47 1 2 3 5 4 6
12345678
B136 B122
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)-115
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 intake air temperature
sensor signal using Subaru Select Monitor or
the 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”. 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 value less than −36°C
(−33°F)?Go to step 2.Repair the poor
contact.
N
OTE:
In this case repair
the following:
 Poor contact in
mass air flow and
intake air tempera-
ture sensor
 Poor contact in
ECM
 Poor contact in
joint connector
2 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air
flow and intake air temperature sensor.
3) Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair the battery
short circuit in har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.Go to step 3.
3 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair the battery
short circuit in har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.Go to step 4.
4 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.
Connector & terminal
(B3) No. 4 (+) — Engine ground (
−):Is the voltage more than 4 V? Go to step 5.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector
 Poor contact in
mass air flow and
intake air tempera-
ture sensor
 Poor contact in
ECM
 Poor contact in
joint connector

EN(H4DOTC)-116
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
5 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between mass air flow and intake air tempera-
ture sensor and engine ground.
Connector & terminal
(B3) No. 5 — Engine ground:Is the resistance less than 5
Ω?Replace the mass
air flow and intake
air temperature
sensor. FU(H4DOTC)-35,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector
 Poor contact in
mass air flow and
intake air tempera-
ture sensor
 Poor contact in
ECM
 Poor contact in
joint connector Step Check Yes No

EN(H4DOTC)-117
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Q: DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT
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 ERATION, Clear Memory Mode.> and Inspection Mode .
WIRING DIAGRAM:
EN-02325
B122
B136 ECM
35 14
E8 ENGINE
COOLANT
TEMPERATURE
SENSOR2
1
1 2
17
18
22
16F74
B200
LHD
LHD
RHD
RHD
LHD LHD
RHD
RHD
E8
12
3
B136
125678
131415169101112
34
17181920
B122B22 : RHD
F61 : LHD
F61
E2
: LHD
B22: RHD
F74
34
12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 7
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
12345678
: LHDE3: RHD