2004 SUBARU FORESTER check engine

EN(H4SO)-177
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.Does the speedometer and
tachometer operate normally?Go to step 2.Repair or replace
the combination
meter. 3, Combination
Meter System.>
2 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 25 (+) — Chassis ground (
−):Is the voltage more than 4.75
V?Go to step 3.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
fuel pump connec-
tor
 Poor contact in
coupling connector
3 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the combination meter connec-
tor (i11) and ECM connector.
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM and chassis ground.
Connector & terminal
(B135) No. 25 (+) — Chassis ground (
−):Is the voltage more than 4.75
V?Go to step 4.Repair battery
short circuit
between ECM and
combination meter
connector.
4 CHECK HARNESS BETWEEN ECM AND
FUEL TANK CORD.
1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Measure the resistance between ECM and
fuel tank cord.
Connector & terminal
(B135) No. 25 — (R15) No. 2:Is the resistance less than 5
Ω?Go to step 5.Repair open circuit
between ECM and
fuel tank cord.
5 CHECK HARNESS BETWEEN FUEL TANK
CORD AND CHASSIS GROUND.
Measure the resistance between fuel tank cord
and chassis ground.
Connector & terminal
(R15) No. 3 — Chassis ground:Is the resistance less than 5
Ω?Go to step 6.Repair open circuit
between fuel tank
cord and chassis
ground.
N
OTE:
In this case repair
the following:
Poor contact in
coupling connec-
tor.
6 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel level
sensor.
2) Measure the resistance between fuel level
sensor and coupler connector.
Connector & terminal
(R57) No. 3 — (R58) No. 5:Is the resistance less than 10
Ω?Go to step 7.Repair open circuit
between coupling
connector and fuel
level sensor.

EN(H4SO)-178
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel sub
level sensor.
2) Measure the resistance between fuel level
sensor and fuel sub level sensor.
Connector & terminal
(R58) No. 3 — (R59) No. 2:Is the resistance less than 10
Ω?Go to step 8.Repair open circuit
between fuel level
sensor and fuel
sub level sensor.
8 CHECK FUEL TANK CORD.
Measure the resistance between fuel level sen-
sor and coupler connector.
Connector & terminal
(R57) No. 2 — (R59) No. 1:Is the resistance less than 10
Ω?Go to step 9.Repair open circuit
between coupling
connector and fuel
level sensor.
9 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4SO)-57, Fuel Level Sensor.>
2) While moving the fuel level sensor float up
and down, measure resistance between fuel
level sensor terminals.
Te r m i n a l s
No. 3 — No. 5:Is the resistance more than
54.5 Ω?Replace the fuel
level sensor. to FU(H4SO)-57,
Fuel Level Sen-
sor.>Go to step 10.
10 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4SO)-58, Fuel Sub Level Sensor.>
2) While moving the fuel sub level sensor float
up and down, measure resistance between
fuel sub level sensor terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance more than
41.5 Ω?Replace the fuel
sub level sensor.
FU(H4SO)-58,
Fuel Sub Level
Sensor.>Replace the com-
bination meter.
Combination
Meter Assembly.> Step Check Yes No

EN(H4SO)-180
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 DTC
P0462 or P0463
using “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>Go to step 2.
2 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4SO)-55, Fuel Pump.>
2) While moving the fuel level sensor float up
and down, make sure that the resistance
between fuel level sensor terminals changes
smoothly.
Te r m i n a l s
No. 3 — No. 5:Does the resistance change
slowly?Go to step 3.Replace the fuel
level sensor. to FU(H4SO)-57,
Fuel Level Sen-
sor.>
3 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4SO)-57, Fuel Level Sensor.>
2) While moving the fuel sub level sensor float
up and down, make sure that the resistance
between fuel level sensor terminals changes
smoothly.
Te r m i n a l s
No. 1 — No. 2:Does the resistance change
slowly?Repair poor con-
tact in ECM, com-
bination meter and
coupling connec-
tors.Replace the fuel
sub level sensor.
FU(H4SO)-58,
Fuel Sub Level
Sensor.>

EN(H4SO)-181
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AU:DTC P0483 COOLING FAN RATIONALITY CHECK
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 Occurrence of noise
 Over-heating
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
NOTE:
If the vehicle, with the engine idling, is placed very close to a wall or another vehicle, preventing normal cool-
ing function, the OBD system may detect malfunction.

EN(H4SO)-183
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(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>Check radiator fan
and fan motor, and
poor contact in
connectors. to CO(H4SO)-35,
Radiator Main Fan
and Fan Motor.>
CO(H4SO)-40,
Radiator Sub Fan
and Fan Motor.>

EN(H4SO)-186
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK TRANSMISSION TYPE.Is the transmission type AT? Go to step 2.Go to step 3.
2 CHECK DTC P0720 ON DISPLAY.Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0720?Check front vehi-
cle speed sensor
signal circuit.
4AT(H4SO)-45,
DTC 33 FRONT
VEHICLE SPEED
SENSOR, Diag-
nostic Procedure
with Diagnostic
Trouble Code
(DTC).>Go to step 3.
3 CHECK SPEEDOMETER OPERATION IN
COMBINATION METER.Does speedometer operate
normally?Go to step 4.Check speedome-
ter and vehicle
speed sensor.
Speedometer.>
Front Vehicle
Speed Sensor.>
Rear Vehicle
Speed Sensor.>
Torque Converter
Turbine Speed
Sensor.>
4 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the combi-
nation meter.
3) Measure the resistance between ECM and
combination meter connector.
Connector & terminal
(B137) No. 10 — (i10) No. 12:Is the resistance less than 10
Ω?Repair the poor
contact in ECM
connector.Repair harness
and connector.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and combi-
nation meter con-
nector
 Poor contact in
ECM connector.
 Poor contact in
combination meter
connector
 Poor contact in
coupling connector

EN(H4SO)-188
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 DTC
using “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>
N
OTE:
In this case, it is not
necessary to in-
spect DTC P0506.Go to step 2.
2 CHECK AIR BY-PASS LINE.
1) Turn the ignition switch to OFF.
2) Remove the idle air control solenoid valve
from the throttle body. REMOVAL, Idle Air Control Solenoid Valve.>
3) Remove the throttle body to intake mani-
fold. tle Body.>
4) Using an air gun, force air into the idle air
control solenoid valve installation area. Con-
firm that forced air subsequently escapes from
throttle body.Does air flow out? Replace the idle
air control solenoid
valve. FU(H4SO)-33,
INSTALLATION,
Idle Air Control
Solenoid Valve.>Replace the throt-
tle body. FU(H4SO)-13,
INSTALLATION,
Throttle Body.>

EN(H4SO)-190
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 DTC
using “List of Diag-
nostic Trouble
Code (DTC)”.
EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>
N
OTE:
In this case, it is not
necessary to in-
spect DTC P0507.Go to step 2.
2 CHECK AIR INTAKE SYSTEM.
1) Turn the ignition switch to ON.
2) Start and idle the engine.
3) Check the following items:
 Loose installation of intake manifold, idle air
control solenoid valve and throttle body
 Cracks of intake manifold gasket, idle air
control solenoid valve gasket and throttle body
gasket
 Disconnections of vacuum hosesIs there any fault in air intake
system?Repair air suction
and leaks.Go to step 3.
3 CHECK THROTTLE CABLE.Is the free play of throttle cable
appropriate?Go to step 4.Adjust throttle
cable. SP(H4SO)-9,
INSTALLATION,
Accelerator Con-
trol Cable.>
4 CHECK AIR BY-PASS LINE.
1) Turn the ignition switch to OFF.
2) Remove the idle air control solenoid valve
from the throttle body. REMOVAL, Idle Air Control Solenoid Valve.>
3) Confirm that there are no foreign particles
in air by-pass line.Are foreign particles in air by-
pass line?Remove foreign
particles from air
by-pass line.Replace the idle
air control solenoid
valve. FU(H4SO)-33,
INSTALLATION,
Idle Air Control
Solenoid Valve.>