2004 SUBARU FORESTER replace disc

EN(H4SO)-159
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).>Go to step 2.
2 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Measure the resistance of harness
between camshaft position sensor connector
and engine ground.
Connector & terminal
(E15) No. 1 — Engine ground:Is the resistance more than
100 kΩ?Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor and ECM
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorGo to step 3.
3 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
Measure the resistance of harness between
camshaft position sensor connector and
engine ground.
Connector & terminal
(E15) No. 1 — Engine ground:Is the resistance less than 10
Ω?Repair ground
short circuit in har-
ness between
camshaft position
sensor and ECM
connector.
N
OTE:
The harness be-
tween both con-
nectors are
shielded. Repair
ground short circuit
in harness togeth-
er with shield.Go to step 4.
4 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM CONNEC-
TOR.
Measure the resistance of harness between
camshaft position sensor connector and
engine ground.
Connector & terminal
(E15) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 5.Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor and ECM
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 6.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
6 CHECK CAMSHAFT POSITION SENSOR.
1) Remove the camshaft position sensor.
2) Measure the resistance between connector
terminals of camshaft position sensor.
Te r m i n a l
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Go to step 7.Replace the cam-
shaft position sen-
sor. FU(H4SO)-27,
Camshaft Position
Sensor.>

EN(H4SO)-162
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).>Go to step 2.
2 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of intake manifold absolute
pressure sensor signal using Subaru Select
Monitor or OBD-II scan tool.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.>
 OBD-II scan tool
For detailed operation procedures, refer to the
OBD-II Scan Tool Instruction Manual.Is the value more than 53.3
kPa (400 mmHg, 15.75 inHg)?Make sure that the
EGR valve, mani-
fold absolute pres-
sure sensor and
throttle body are
tightened firmly.Go to step 3.
3 CHECK THE POWER SUPPLY OF EGR
VALVE.
1) Disconnect the connector from EGR valve.
2) Turn the ignition switch to ON.
3) Measure the voltage between EGR valve
and engine ground.
Connector & terminal
(E18) No. 2 — Engine ground:
(E18) No. 5 — Engine ground:Is the voltage more than 10 V? Go to step 4.Repair open circuit
in harness
between main
relay and EGR
valve connector.
4 CHECK EGR VALVE.
Measure the resistance between EGR valve
terminals.
N
OTE:
Make sure there is no foreign material between
EGR valve and valve seat.
Te r m i n a l s
No. 1 — No. 2:
No. 3 — No. 2:
No. 4 — No. 5:
No. 6 — No. 5:Is the resistance 20 — 30 Ω? Go to step 5.Replace the EGR
valve. FU(H4SO)-34,
EGR Valve.>
5 OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the connector to ECM and EGR
valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 15 (+) — Chassis ground (
−):
(B134) No. 16 (+) — Chassis ground (
−):
(B134) No. 17 (+) — Chassis ground (
−):
(B134) No. 18 (+) — Chassis ground (
−):Is the voltage 0 — 10 V? Repair poor con-
tact portion in
ECM connector.Go to step 6.

EN(H4SO)-165
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).>
N
OTE:
In this case, it is not
necessary to in-
spect DTC P0420.Go to step 2.
2 CHECK EXHAUST SYSTEM.
Check for gas leaks or air suction caused by
loose or dislocated nuts and bolts, and open
hole at exhaust pipes.
NOTE:
Check the following positions.
 Between cylinder head and front exhaust
pipe
 Between front exhaust pipe and front cata-
lytic converter
 Between front catalytic converter and rear
catalytic converterIs there a fault in exhaust sys-
tem?Repair or replace
the exhaust sys-
tem. EX(H4SO)-2, Gen-
eral Description.>Go to step 3.
3 CHECK CATALYTIC CONVERTER.Is there damage at rear face or
front face of catalytic con-
ver ter?Replace catalytic
converter. EC(H4SO)-3,
Front Catalytic
Converter.>Go to step 4.
4 CHECK REAR OXYGEN SENSOR CIRCUIT
MALFUNCTION.
1) Disconnect the connector from rear oxygen
sensor and ECM.
2) Measure the resistance between rear oxy-
gen sensor connector and ECM connector.
Connector & terminal
(T6) No. 3 — (B135) No. 19:Is the resistance less than 1
Ω?Go to step 5.Repair battery
open circuit in har-
ness between
ECM and rear oxy-
gen sensor.
5 CHECK SHIELD WIRE.Is the shield wire opened? Repair the shield
wire.Contact the SUB-
ARU dealer.

EN(H4SO)-167
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 29 (+) — Chassis ground (
−):Is the voltage more than 10 V? Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. Contact
the SUBARU
dealer.
N
OTE:
Inspection by DTM
is required, because
probable cause is
deterioration of mul-
tiple parts.Go to step 2.
2 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from purge con-
trol solenoid valve and ECM.
3) Measure the resistance of harness
between purge control solenoid valve connec-
tor and engine ground.
Connector & terminal
(E4) No. 2 — Engine ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
3 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
Measure the resistance of harness between
ECM and purge control solenoid valve of har-
ness connector.
Connector & terminal
(B134) No. 29 — (E4) No. 2:Is the resistance less than 1
Ω?Go to step 4.Repair open circuit
in harness
between ECM and
purge control sole-
noid valve connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and purge
control solenoid
valve connector
 Poor contact in
coupling connector
4 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Remove the purge control solenoid valve.
2) Measure the resistance between purge
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 10 — 100 Ω? Go to step 5.Replace the purge
control solenoid
valve. EC(H4SO)-9,
Purge Control
Solenoid Valve.>
5 CHECK POWER SUPPLY TO PURGE CON-
TROL SOLENOID VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between purge control
solenoid valve and engine ground.
Connector & terminal
(E4) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 6.Repair open circuit
in harness
between main
relay and purge
control solenoid
valve connector.

EN(H4SO)-170
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector at the
lower portion of instrument panel (on the
driver’s side).
3) Turn the ignition switch to ON.
4) While operating the purge control solenoid
valve, measure voltage between ECM and
chassis ground.
N
OTE:
Purge control solenoid valve operation can be
executed using Subaru Select Monitor. Refer to
“Compulsory Valve Operation Check Mode” for
procedures. sory Valve Operation Check Mode.>
Connector & terminal
(B134) No. 29 (+) — Chassis ground (
−):Is the voltage 0 — 10 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. In this
case, repair poor
contact in ECM
connector.
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 29 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Go to step 3.
3 CHECK POOR CONTACT.
Check poor contact in ECM connector. Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>
4 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from purge con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 29 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
After repair,
replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 5.
5 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between purge
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 1
Ω?Replace the purge
control solenoid
valve EC(H4SO)-9,
Purge Control
Solenoid Valve.>
and ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 6.
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>

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 less than 0.12
V?
Go to step
4.Go to step 3.
3 CHECK INPUT SIGNAL FOR ECM (WITH SUBARU SELECT MONITOR).
Read the data of fuel level sensor signal using
Subaru Select Monitor.
N
OTE:
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.> Is the voltage less than 0.12 V
by shaking the ECM harness
and connector?
Repair the poor
contact in ECM
connector.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.
NOTE:
In this case repair
the following:
 Poor contact in
combination meter
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
4 CHECK INPUT VOLTAGE OF ECM. 1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM connector and chassis ground.Connector & terminal
(B135) No. 25 (+) — Chassis ground (
−): Is the voltage more than 0.12
V?
Go to step
5.Go to step 6.
5 CHECK HARNESS BETWEEN ECM AND COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from connector
(i10) and ECM connector.
3) Measure the resistance between ECM and
chassis ground.Connector & terminal (B135) No. 25 — Chassis ground: Is the resistance more than 1
M
Ω? Go to step
7.Repair the ground
short in harness
between ECM and
combination meter
connector.
6 CHECK HARNESS BETWEEN ECM AND COMBINATION METER.
Measure the resistance between ECM and
combination meter connector.Connector & terminal (B135) No. 25 — (i11) No. 1: Is the resistance less than 10
Ω
? Repair or replace
the combination
meter. 3, Combination
Meter System.>Repair open circuit
between ECM and
combination meter
connector.
NOTE:
In this case repair
the following:
Poor contact in
coupling connector
EN(H4SO)-174

EN(H4SO)-175
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FUEL TANK CORD.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel sub
level sensor.
3) Measure the resistance between fuel sub
level sensor and chassis ground.
Connector & terminal
(R59) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 8.Repair ground
short circuit in fuel
tank cord.
8 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel pump
assembly.
2) Measure the resistance between fuel pump
assembly and chassis ground.
Connector & terminal
(R59) No. 2 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 9.Repair ground
short circuit in fuel
tank cord.
9 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4SO)-57, Fuel Level Sensor.>
2) Measure the resistance between fuel level
sensor and terminals with its float set to the full
position.
Te r m i n a l s
No. 3 — No. 5:Is the resistance 0.5 — 2.5 Ω? Go to step 10.Replace the fuel
level sensor.
10 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4SO)-58, Fuel Sub Level Sensor.>
2) Measure the resistance between fuel sub
level sensor and terminals with its float set to
the full position.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 0.5 — 2.5 Ω? Repair poor con-
tact in harness
between ECM and
combination meter
connector.Replace the fuel
sub level sensor. Step Check Yes No

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.