check engine SUBARU FORESTER 2004 Service Repair Manual
[x] Cancel search | Manufacturer: SUBARU, Model Year: 2004, Model line: FORESTER, Model: SUBARU FORESTER 2004Pages: 2870, PDF Size: 38.67 MB
Page 1742 of 2870
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.
36, Manifold Abso-
lute Pressure Sen-
sor.>
Page 1744 of 2870
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)”.
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”.
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.
Mass Air Flow and
Intake Air Temper-
ature Sensor.>Inspect the DTC
P0125 using “List
of Diagnostic Trou-
ble Code (DTC)”.
List of Diagnostic
Trouble Code
(DTC).>
Page 1746 of 2870
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”.
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”.
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.
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.
Page 1748 of 2870
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”.
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
Page 1749 of 2870
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.
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
Page 1751 of 2870
EN(H4DOTC)-118
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 engine coolant tempera-
ture 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”.
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 120°C (248°F)?Go to step 2.Repair the poor
contact.
N
OTE:
In this case repair
the following:
Poor contact in
engine coolant
temperature sen-
sor
Poor contact in
ECM
Poor contact in
coupling connector
Poor contact in
joint connector
2 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the engine
coolant temperature sensor.
3) Turn the ignition switch to ON.
4) Read the data of engine coolant tempera-
ture sensor signal using Subaru Select Monitor
or the OBD-II general scan tool.
NOTE:
Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”.
OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the temperature more than
−40°C (−40°F)?Replace the
engine coolant
temperature sen-
sor.
Engine Coolant
Temperature Sen-
sor.>Repair ground
short circuit in har-
ness between
engine coolant
temperature sen-
sor and ECM con-
nector.
Page 1753 of 2870
EN(H4DOTC)-120
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 engine coolant tempera-
ture 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”.
OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the value less than −40°C
(−40°F)?Go to step 2.Repair the poor
contact.
N
OTE:
In this case repair
the following:
Poor contact in
engine coolant
temperature sen-
sor
Poor contact in
ECM
Poor contact in
coupling connector
Poor contact in
joint connector
2 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the engine
coolant temperature sensor.
3) Measure the voltage between engine cool-
ant temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and engine
coolant tempera-
ture sensor con-
nector.Go to step 3.
3 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between engine cool-
ant temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and engine
coolant tempera-
ture sensor con-
nector.Go to step 4.
4 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
Measure the voltage between engine coolant
temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) — 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 engine
coolant tempera-
ture sensor con-
nector
Poor contact in
engine coolant
temperature sen-
sor connector
Poor contact in
ECM connector.
Poor contact in
coupling connector
Poor contact in
joint connector
Page 1754 of 2870
EN(H4DOTC)-121
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
5 CHECK HARNESS BETWEEN ENGINE
COOLANT TEMPERATURE SENSOR AND
ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between engine coolant temperature sensor
connector and engine ground.
Connector & terminal
(E8) No. 1 — Engine ground:Is the resistance less than 5
Ω?Replace the
engine coolant
temperature sen-
sor.
Engine Coolant
Temperature Sen-
sor.>Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ECM and engine
coolant tempera-
ture sensor con-
nector
Poor contact in
engine coolant
temperature sen-
sor connector
Poor contact in
ECM connector.
Poor contact in
coupling connector
Poor contact in
joint connector Step Check Yes No
Page 1756 of 2870
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)”.
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.
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
Page 1759 of 2870
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”.
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.