2004 SUBARU FORESTER engine

EN(H4DOTC)-123
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
RHD model
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
P0121.Replace the throt-
tle position sen-
sor. FU(H4DOTC)-34,
Throttle Position
Sensor.>
EN-02327
E3
E13
B22
B122 THROTTLE
POSITION
SENSOR
1
32
20
1918
1 2
B136 ECM
16
35 18
B136
E13
123
B22
125678
131415169101112
34
17181920
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
12345678

EN(H4DOTC)-124
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
T: DTC P0122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT
LOW INPUT
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:
LHD model
EN-02326
E2
E13
F61
F74
B200
B122 THROTTLE
POSITION
SENSOR
1
32
20
1918
1 2
B136 ECM
16
35 18
B136
E13
123
F61
125678
131415169101112
34
17181920
B122
F2
F2
B100
F74
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
34
12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 7
1234 5678910 11 12 13 14 15 16 17 18 19 20
723
16

EN(H4DOTC)-125
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
RHD model
EN-02327
E3
E13
B22
B122 THROTTLE
POSITION
SENSOR
1
32
20
1918
1 2
B136 ECM
16
35 18
B136
E13
123
B22
125678
131415169101112
34
17181920
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
12345678

EN(H4DOTC)-126
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 throttle position sensor
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”. 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 voltage less than 0.15
V?Go to step 2.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.A tempo-
rary poor contact
of the connector
may be the cause.
N
OTE:
In this case repair
the following:
 Poor contact in
throttle position
sensor connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
2 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground while throttle valve is fully
closed.
Connector & terminal
(B136) No. 16 (+) — Chassis ground (
−):Is the voltage more than 4.5 V? Go to step 4.Go to step 3.
3 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.
4 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 18 (+) — Chassis ground (
−):Is the voltage less than 0.15
V?Go to step 6.Go to step 5.
5 CHECK INPUT SIGNAL FOR ECM (WITH
SUBARU SELECT MONITOR).
Measure the voltage between ECM connector
and chassis ground.Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with Subaru
Select Monitor?Repair the poor
contact in ECM
connector.Go to step 6.

EN(H4DOTC)-127
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from throttle
position sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between throttle posi-
tion sensor connector and engine ground.
Connector & terminal
(E13) No. 1 (+) — Engine ground (
−):Is the voltage more than 4.5 V? Go to step 7.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
throttle position
sensor and ECM
connector
 Poor contact in
throttle position
sensor connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
 Poor contact in
joint connector
7 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between ECM connector and throttle position
sensor connector.
Connector & terminal
(B136) No. 18 — (E13) No. 3:Is the resistance less than 1
Ω?Go to step 8.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
throttle position
sensor and ECM
connector
 Poor contact in
ECM connector
 Poor contact in
throttle position
sensor connector
 Poor contact in
coupling connector
8 CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
Measure the resistance of harness between
throttle position sensor connector and engine
ground.
Connector & terminal
(E13) No. 3 — Engine ground:Is the resistance more than 1
MΩ?Go to step 9.Repair ground
short circuit in har-
ness between
throttle position
sensor and ECM
connector.
9 CHECK POOR CONTACT.
Check poor contact in throttle position sensor
connector.Is there poor contact in throttle
position sensor connector?Repair poor con-
tact in throttle posi-
tion sensor
connector.Replace the throt-
tle position sen-
sor. FU(H4DOTC)-34,
Throttle Position
Sensor.> Step Check Yes No

EN(H4DOTC)-128
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
U: DTC P0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT
HIGH INPUT
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:
LHD model
EN-02326
E2
E13
F61
F74
B200
B122 THROTTLE
POSITION
SENSOR
1
32
20
1918
1 2
B136 ECM
16
35 18
B136
E13
123
F61
125678
131415169101112
34
17181920
B122
F2
F2
B100
F74
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
34
12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 2456 7
1234 5678910 11 12 13 14 15 16 17 18 19 20
723
16

EN(H4DOTC)-129
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
RHD model
EN-02327
E3
E13
B22
B122 THROTTLE
POSITION
SENSOR
1
32
20
1918
1 2
B136 ECM
16
35 18
B136
E13
123
B22
125678
131415169101112
34
17181920
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
12345678

EN(H4DOTC)-130
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 throttle position sensor
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”. 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 voltage more than 4.7 V? Go to step 2.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.A tempo-
rary poor contact
of the connector
may be the cause.
N
OTE:
In this case repair
the following:
 Poor contact in
throttle position
sensor connector
 Poor contact in
ECM connector
 Poor contact in
coupling connector
2 CHECK HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from throttle
position sensor.
3) Measure the resistance of harness
between throttle position sensor connector and
engine ground.
Connector & terminal
(E13) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 3.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
throttle position
sensor and ECM
connector
 Poor contact in
coupling connector
 Poor contact in
joint connector
3 CHECK HARNESS BETWEEN THROTTLE
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between throttle posi-
tion sensor connector and engine ground.
Connector & terminal
(E13) No. 3 (+) — Engine ground (
−):Is the voltage more than 4.7 V? Repair the battery
short circuit in har-
ness between
throttle position
sensor and ECM
connector.After
repair, replace the
ECM. FU(H4DOTC)-50,
Engine Control
Module (ECM).>Replace the throt-
tle position sen-
sor. FU(H4DOTC)-34,
Throttle Position
Sensor.>