display SUBARU FORESTER 2004 Service Owners Manual

EN(H4DOTC)-142
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and keep
the engine speed at 2,000 rpm to 3,000 rpm for
two minutes.
2) Read the data of rear 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
“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.Does the value fluctuate? Go to step 6.Go to step 3.
3 CHECK REAR OXYGEN SENSOR DATA.
Read the data of rear oxygen (A/F) sensor sig-
nal using Subaru Select Monitor or OBD-II
general scan tool.Is the voltage 0.2 — 0.4 V? Go to step 4.Replace the rear
oxygen sensor.
FU(H4DOTC)-47,
Rear Oxygen Sen-
sor.>
4 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance in harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B137) No. 25 — (T6) No. 4:Is the resistance more than 3
Ω?Repair battery
short circuit in har-
ness between
ECM and rear oxy-
gen sensor con-
nector.Go to step 5.
5 CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR and ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from rear oxygen
sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between rear oxygen
sensor harness connector and engine ground
or chassis ground.
Connector & terminal
(T6) No. 4 (+) — Engine ground (
−):Is the voltage more than 0.2 V? Replace the rear
oxygen sensor.
FU(H4DOTC)-47,
Rear Oxygen Sen-
sor.>Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
rear oxygen sen-
sor and ECM con-
nector
 Poor contact in
rear oxygen sen-
sor connector
 Poor contact in
ECM connector.

EN(H4DOTC)-145
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70°C (158°F), and keep
the engine speed at 2,000 rpm to 3,000 rpm for
two minutes.
2) Read the data of rear 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
“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.Does the value fluctuate? Go to step 6.Go to step 3.
3 CHECK REAR OXYGEN SENSOR DATA.
Read the data of rear oxygen (A/F) sensor sig-
nal using Subaru Select Monitor or OBD-II
general scan tool.Is the voltage 0.2 — 0.4 V? Go to step 4.Replace the rear
oxygen sensor.
FU(H4DOTC)-47,
Rear Oxygen Sen-
sor.>
4 CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
rear oxygen sensor.
3) Measure the resistance in harness
between ECM and rear oxygen sensor con-
nector.
Connector & terminal
(B137) No. 25 — (T6) No. 4:Is the resistance more than 3
Ω?Repair battery
short circuit in har-
ness between
ECM and rear oxy-
gen sensor con-
nector.Go to step 5.
5 CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR and ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from rear oxygen
sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between rear oxygen
sensor harness connector and engine ground
or chassis ground.
Connector & terminal
(T6) No. 4 (+) — Engine ground (
−):Is the voltage more than 0.2 V? Replace the rear
oxygen sensor.
FU(H4DOTC)-47,
Rear Oxygen Sen-
sor.>Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
rear oxygen sen-
sor and ECM con-
nector
 Poor contact in
rear oxygen sen-
sor connector
 Poor contact in
ECM connector

EN(H4DOTC)-148
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AE:DTC P0171 SYSTEM TOO LEAN (BANK 1)
NOTE:
For diagnostic procedure, refer to DTC P0172. (BANK 1), 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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>
N
OTE:
In this case, it is
not necessary to
inspect DTC
P0139.Replace the rear
oxygen sensor.
FU(H4DOTC)-47,
Rear Oxygen Sen-
sor.>

EN(H4DOTC)-157
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>
N
OTE:
In this case, it is
not necessary to
inspect DTC
P0244.Replace the
wastegate control
solenoid valve.
FU(H4DOTC)-44,
Wastegate Con-
trol Solenoid Valve
Assembly.>

EN(H4DOTC)-166
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground on faulty cylinders.
Connector & terminal
#1 (B136) No. 6 (+) — Chassis ground (
−):
#2 (B136 No. 5 (+) — Chassis ground (
−):
#3 (B136 No. 4 (+) — Chassis ground (
−):
#4 (B136 No. 3 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 7.Go to step 3.
3 CHECK HARNESS BETWEEN FUEL INJEC-
TOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel injector
on faulty cylinder.
3) Disconnect the connector from ECM.
4) Measure the voltage between ECM con-
nector and engine ground on faulty cylinders.
Connector & terminal
#1 (E5) No. 1 — Engine ground:
#2 (E16) No. 1 — Engine ground:
#3 (E6) No. 1 — Engine ground:
#4 (E17) No. 1 — Engine ground:Is the resistance more than 1
MΩ?Go to step 4.Repair ground
short circuit in har-
ness between fuel
injector and ECM
connector.
4 CHECK HARNESS BETWEEN FUEL INJEC-
TOR AND ECM CONNECTOR.
Measure the resistance of harness connector
between ECM connector and fuel injector on
faulty cylinders.
Connector & terminal
#1 (B136) No. 6 — (E5) No. 1:
#2 (B136) No. 5 — (E16) No. 1:
#3 (B136) No. 4 — (E6) No. 1:
#4 (B136) No. 3 — (E17) No. 1:Is the resistance less than 1
Ω?Go to step 5.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and fuel
injector connector
 Poor contact in
coupling connector
5 CHECK FUEL INJECTOR.
Measure the resistance between fuel injector
terminals on faulty cylinder.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 5 — 20 Ω? Go to step 6.Replace the faulty
fuel injector. to FU(H4DOTC)-
38, Fuel Injector.>

EN(H4DOTC)-176
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK CONDITION OF CRANKSHAFT PO-
SITION SENSOR.
Turn the ignition switch to OFF.Is the crankshaft position sen-
sor installation bolt tightened
securely?Go to step 3.Tighten the crank-
shaft position sen-
sor installation bolt
securely.
3 CHECK CRANK SPROCKET.
Remove the front belt cover.Are crank sprocket teeth
cracked or damaged?Replace the crank
sprocket. ME(H4DOTC)-67,
Crank Sprocket.>Go to step 4.
4 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the crankshaft, and align alignment mark
on crank sprocket with alignment mark on cyl-
inder block.Is the timing belt dislocated
from its proper position?Repair installation
condition of timing
belt. ME(H4DOTC)-58,
Timing Belt
Assembly.>Replace the crank-
shaft position sen-
sor. FU(H4DOTC)-30,
Crankshaft Posi-
tion Sensor.>

EN(H4DOTC)-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 rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”. EN(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR CONNECTOR AND ECM
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor connector.
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 the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor connector
and ECM connec-
tor
 Poor contact in
ECM connector
 Poor contact in
coupling connectorGo to step 3.
3 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR CONNECTOR AND ECM
CONNECTOR.
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 connector
and ECM connec-
tor.
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 CONNECTOR AND ECM
CONNECTOR.
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 the har-
ness and connec-
tor.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
camshaft position
sensor connector
and ECM connec-
tor
 Poor contact in
ECM connector
 Poor contact in
coupling connector

EN(H4DOTC)-187
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>
N
OTE:
In this case, it is
not necessary to
inspect 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.
N
OTE:
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(H4DOTC)-2,
General Descrip-
tion.>Go to step 3.
3 CHECK REAR CATALYTIC CONVERTER.
Separate rear catalytic converter from rear
exhaust pipe.Is there damage at rear face of
rear catalyst?Replace the front
and rear catalytic
converter EC(H4DOTC)-3,
Front Catalytic
Converter.> to EC(H4DOTC)-4,
Rear Catalytic
Converter.>Go to step 4.
4 CHECK FRONT CATALYTIC CONVERTER.
Remove the front catalytic converter.Is there damage at rear face or
front face of front catalyst?Replace the front
catalytic con-
verter. EC(H4DOTC)-3,
Front Catalytic
Converter.>Contact the SUB-
ARU dealer.
NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

EN(H4DOTC)-193
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>
N
OTE:
In this case, it is
not necessary to
inspect DTC
P0461.Replace the fuel
level sensor and
fuel sub level sen-
sor. FU(H4DOTC)-64,
Fuel Level Sen-
sor.> FU(H4DOTC)-65,
Fuel Sub Level
Sensor.>

EN(H4DOTC)-201
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(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly. FU(H4DOTC)-62, 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
smoothly between approx. 0.5
— 52 Ω?Go to step 3.Replace the fuel
level sensor. to FU(H4DOTC)-
64, Fuel Level
Sensor.>
3 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor. FU(H4DOTC)-65, Fuel Sub 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
smoothly between approx. 0.5
— 44 Ω?Repair poor con-
tact in ECM, com-
bination meter and
coupling connec-
tors.Replace the fuel
sub level sensor.
FU(H4DOTC)-65,
Fuel Sub Level
Sensor.>