engine coolant 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 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 1750 of 2870

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
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
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 1752 of 2870

EN(H4DOTC)-119
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
R: DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH 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
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
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 1764 of 2870

EN(H4DOTC)-131
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
V: DTC P0125 INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP
FUEL CONTROL
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Engine would not return to idling.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory 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
Page 1765 of 2870

EN(H4DOTC)-132
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
W: DTC P0129 BAROMETRIC PRESSURE TOO LOW
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode
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
P0125.Go to step 2.
2 CHECK ENGINE COOLING SYSTEM.
N
OTE:
Check the following items:
Thermostat open stuck
Coolant level
Coolant freeze
Tire diameterIs there a fault in engine cool-
ing system?Replace the ther-
mostat.
Thermostat.>Replace the
engine coolant
temperature sen-
sor.
Engine Coolant
Temperature Sen-
sor.>
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:
It is not necessary
to inspect DTC
P0129.Replace the ECM.
Engine Control
Module (ECM).>
NOTE:
Atmospheric pres-
sure sensor is built
in ECM.
Page 1773 of 2870

EN(H4DOTC)-140
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).>Go to step 2.
2 CHECK FRONT (A/F) OXYGEN SENSOR DA-
TA.
1) Start the engine.
2) While observing the Subaru Select Monitor
or OBD-II general scan tool screen, warm-up
the engine until coolant temperature is above
70°C (158°F).
If the engine is already warmed-up, operate at
idle speed for at least 1 minute.
3) Read the data of front oxygen (A/F) sensor
signal using Subaru Select Monitor or OBD-II
general scan tool.
N
OTE:
Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”.
OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.Is the measured value 0.85 —
1.15 (in idling)?Go to step 3.Go to step 4.
3 CHECK REAR OXYGEN SENSOR SIGNAL.
1) Race the engine at speeds from idling to
5,000 rpm for a total of 5 cycles.
N
OTE:
To increase the engine speed to 5,000 rpm,
slowly depress accelerator pedal, taking ap-
prox. 5 seconds, and quickly release accelera-
tor pedal to decrease engine speed.
2) Operate the LED operation mode for
engine.
N
OTE:
Subaru Select Monitor
For detailed operation procedure, refer to the
“LED OPERATION MODE FOR ENGINE”.
2 Rich
Signal} blink?Repair the poor
contact in front
oxygen (A/F) sen-
sor and rear oxy-
gen sensor
connector.Check the rear
oxygen sensor cir-
cuit.
Rear Oxygen Sen-
sor.>
4 CHECK EXHAUST SYSTEM.
Check the exhaust system parts.
NOTE:
Check the following items.
Loose installation of portions
Damage (crack, hole etc.) of parts
Looseness of front oxygen (A/F) sensor
Looseness and ill fitting of parts between
front oxygen (A/F) sensor and rear oxygen
sensorIs there a fault in exhaust sys-
tem?Repair or replace
the faulty par ts.Replace the front
oxygen (A/F) sen-
sor.
Front Oxygen (A/
F) Sensor.>