2004 SUBARU FORESTER check engine

EN(H4DOTC)-168
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
12 CHECK FUEL LEVEL.Is the fuel meter indication
higher than the “Lower” level?Go to step 13.Replenish fuel so
fuel meter indica-
tion is higher than
the “Lower”
level.After replen-
ishing fuel, Go to
step 13.
13 CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1) Clear the memory using Subaru Select
Monitor.
Mode.>
2) Start the engine, and drive the vehicle more
than 10 minutes.Does the malfunction indicator
light illuminate or blink?Go to step 15.Go to step 14.
14 CHECK CAUSE OF MISFIRE DIAGNOSED.Was the cause of misfire diag-
nosed when the engine is run-
ning?Finish diagnostics
operation, if the
engine has no
abnormality.Repair the poor
contact.
N
OTE:
In this case repair
the following:
 Poor contact in
ignition coil con-
nector
 Poor contact in
fuel injector con-
nector on faulty
cylinders
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
15 CHECK AIR INTAKE SYSTEM.Is there any fault in air intake
system?Repair air intake
system.
N
OTE:
Check the follow-
ing items:
 Are there air
leaks or air suction
caused by loose or
dislocated nuts
and bolts?
 Are there cracks
or any disconnec-
tion of hoses?Go to step 16.
16 CHECK CYLINDER.Is there a fault in that cylinder? Repair or replace
the faulty par t.
N
OTE:
Check the follow-
ing items:
 Spark plug
 Fuel injector
 CompressionGo to DTC P0171
and P0172. to EN(H4DOTC)-
148, DTC P0171
SYSTEM TOO
LEAN (BANK 1),
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).> Step Check Yes No

EN(H4DOTC)-170
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN KNOCK SEN-
SOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between ECM har-
ness connector and chassis ground.
Connector & terminal
(B136) No. 25 — Chassis ground:Is the resistance more than
700 kΩ?Go to step 2.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
knock sensor and
ECM connector
 Poor contact in
knock sensor con-
nector
 Poor contact in
coupling connector
2 CHECK KNOCK SENSOR.
1) Disconnect the connector from knock sen-
sor.
2) Measure the resistance between knock
sensor connector terminal and engine ground.
Te r m i n a l s
No. 2 — Engine ground:Is the resistance more than
700 kΩ?Go to step 3.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Poor contact in
knock sensor con-
nector
 Poor contact in
coupling connector
3 CHECK CONDITION OF KNOCK SENSOR
INSTALLATION.Is the knock sensor installation
bolt tightened securely?Replace the knock
sensor. FU(H4DOTC)-33,
Knock Sensor.>Tighten knock sen-
sor installation bolt
securely.

EN(H4DOTC)-172
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN KNOCK SEN-
SOR AND ECM CONNECTOR.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 25 — Chassis ground:Is the resistance less than 400
kΩ?Go to step 2.Go to step 3.
2 CHECK KNOCK SENSOR.
1) Disconnect the connector from knock sen-
sor.
2) Measure the resistance between knock
sensor connector terminal and engine ground.
Te r m i n a l s
No. 2 — Engine ground:Is the resistance less than 400
kΩ?Replace the knock
sensor. FU(H4DOTC)-33,
Knock Sensor.>Repair ground
short circuit in har-
ness between
knock sensor con-
nector and ECM
connector.
N
OTE:
The harness be-
tween both con-
nectors are
shielded.Repair
short circuit in har-
ness covered with
shield.
3 CHECK INPUT SIGNAL FROM ECM.
1) Connect the connectors to ECM and knock
sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 25 (+) — Chassis ground (
−):Is the voltage more than 2 V? Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.(However,
the possibility of
poor contact still
remains.)
NOTE:
In this case repair
the following:
 Poor contact in
knock sensor con-
nector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorRepair the poor
contact in ECM
connector.

EN(H4DOTC)-174
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the crank-
shaft position sensor.
3) Measure the resistance of harness
between crankshaft position sensor connector
and engine ground.
Connector & terminal
(E10) 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
crankshaft posi-
tion sensor and
ECM connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorGo to step 2.
2 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 1 — Engine ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in har-
ness between
crankshaft posi-
tion 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.
3 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 4.Repair the har-
ness and connec-
tor.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
4 CHECK CONDITION OF CRANKSHAFT PO-
SITION SENSOR.Is the crankshaft position sen-
sor installation bolt tightened
securely?Go to step 5.Tighten the crank-
shaft position sen-
sor installation bolt
securely.
5 CHECK CRANKSHAFT POSITION SENSOR.
1) Remove the crankshaft position sensor.
2) Measure the resistance between connector
terminals of crankshaft position sensor.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Repair poor con-
tact in crankshaft
position sensor
connector.Replace the crank-
shaft position sen-
sor. FU(H4DOTC)-30,
Crankshaft Posi-
tion Sensor.>

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)-178
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 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 2.
2 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 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. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 4.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 connector
4 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR CONNECTOR.Is the camshaft position sensor
connector installation bolt tight-
ened securely?Go to step 5.Tighten the cam-
shaft position sen-
sor connector
installation bolt
securely.
5 CHECK CAMSHAFT POSITION SENSOR
CONNECTOR.
1) Remove the camshaft position sensor con-
nector.
2) Measure the resistance between connector
terminals of camshaft position sensor connector.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Repair poor con-
tact in camshaft
position sensor
connector.Replace the cam-
shaft position sen-
sor connector.
FU(H4DOTC)-31,
Camshaft Position
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)-181
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR CONNECTOR.Is the camshaft position sensor
connector installation bolt tight-
ened securely?Go to step 6.Tighten the cam-
shaft position sen-
sor connector
installation bolt
securely.
6 CHECK CAMSHAFT POSITION SENSOR
CONNECTOR.
1) Remove the camshaft position sensor con-
nector.
2) Measure the resistance between connector
terminals of camshaft position sensor connec-
tor.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Go to step 7.Replace the cam-
shaft position sen-
sor connector.
FU(H4DOTC)-31,
Camshaft Position
Sensor.>
7 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR CONNECTOR.
Turn the ignition switch to OFF.Is the camshaft position sensor
connector installation bolt tight-
ened securely?Go to step 8.Tighten the cam-
shaft position sen-
sor connector
installation bolt
securely.
8 CHECK CAM SPROCKET.
Remove the front belt cover. ME(H4DOTC)-57, Timing Belt Cover.>Are cam sprocket teeth
cracked or damaged?Replace the cam
sprocket. ME(H4DOTC)-66,
Cam Sprocket.>Go to step 9.
9 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the crankshaft, and align alignment mark
on camshaft sprocket with alignment mark on
timing belt cover LH.Is the timing belt dislocated
from its proper position?Repair installation
condition of timing
belt. ME(H4DOTC)-58,
Timing Belt
Assembly.>Replace the cam-
shaft position sen-
sor connector.
FU(H4DOTC)-31,
Camshaft Position
Sensor.> Step Check Yes No