check engine 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 1247 of 2870
EN(H4SO)-149
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
(B135) No. 16 — Chassis ground:Is the resistance more than
700 kΩ?Go to step 2.Repair harness
and connector.
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
No. 2 — Engine ground:Is the resistance more than
700 kΩ?Go to step 3.Repair harness
and connector.
NOTE:
In this case repair
the following:
Poor contact in
knock sensor con-
nector
3 CHECK CONDITION OF KNOCK SENSOR
INSTALLATION.Is the knock sensor installation
bolt tightened securely?Replace the knock
sensor.
Knock Sensor.>Tighten knock sen-
sor installation bolt
securely.
Page 1249 of 2870
EN(H4SO)-151
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
(B135) No. 16 — 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.
Knock Sensor.>Repair ground
short circuit in har-
ness between
knock sensor con-
nector and ECM
connector.
N
OTE:
The harness be-
tween both connec-
tors are shielded.
Repair short circuit
in harness 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
(B135) No. 16 (+) — 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. (How-
ever, the possibility
of poor contact still
remains.)
N
OTE:
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.
Page 1251 of 2870
EN(H4SO)-153
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 harness
and connector.
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 less than 10
Ω?Repair ground
short circuit in har-
ness between
crankshaft posi-
tion sensor and
ECM connector.
N
OTE:
The harness be-
tween both connec-
tors are shielded.
Repair ground short
circuit in harness to-
gether with shield.Go to step 3.
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 harness
and connector.
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.
Crankshaft Posi-
tion Sensor.>
Page 1253 of 2870
EN(H4SO)-155
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)”.
of Diagnostic Trou-
ble 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.
Crank Sprocket.>Go to step 4.
4 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the crankshaft using ST, and align align-
ment mark on crank sprocket with alignment
mark on cylinder block.
ST 499987500 CRANKSHAFT SOCKETIs the timing belt dislocated
from its proper position?Repair installation
condition of timing
belt.
Timing Belt.>Replace the crank-
shaft position sen-
sor.
Crankshaft Posi-
tion Sensor.>
Page 1255 of 2870
EN(H4SO)-157
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 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 2.
2 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 connec-
tors are shielded.
Repair ground short
circuit in harness to-
gether with shield.Go 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. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 4.Repair harness
and connector.
NOTE:
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
4 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 5.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
5 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 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.
Camshaft Position
Sensor.>
Page 1257 of 2870
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)”.
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.
Camshaft Position
Sensor.>
Page 1258 of 2870
EN(H4SO)-160
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.
Turn the ignition switch to OFF.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 8.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
8 CHECK CAMSHAFT SPROCKET.
Remove the front belt cover.
cracked or damaged?Replace the cam
sprocket.
Cam Sprocket.>Go to step 9.
9 CHECK INSTALLATION CONDITION OF
TIMING BELT.
Turn the camshaft using ST, and align align-
ment mark on cam sprocket with alignment
mark on timing belt cover LH.
ST 499207100 CAM SPROCKET WRENCHIs the timing belt dislocated
from its proper position?Repair installation
condition of timing
belt.
Timing Belt.>Replace the cam-
shaft position sen-
sor.
Camshaft Position
Sensor.> Step Check Yes No
Page 1260 of 2870
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)”.
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”.
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.
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.
Page 1261 of 2870
EN(H4SO)-163
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK HARNESS BETWEEN EGR VALVE
AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Detach the connector from EGR valve and
ECM.
3) Measure the resistance of harness
between EGR valve and ECM connector.
Connector & terminal
(B134) No. 18 — (E18) No. 6:
(B134) No. 17 — (E18) No. 1:
(B134) No. 16 — (E18) No. 4:
(B134) No. 15 — (E18) No. 3:Is the resistance less than 1
Ω?Go to step 7.Repair open circuit
in harness
between ECM and
EGR valve con-
nector.
7 CHECK HARNESS BETWEEN EGR VALVE
AND ECM CONNECTOR.
Measure the resistance of harness between
EGR valve 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 resistance more than 1
MΩ?Go to step 8.Repair short circuit
in harness
between main
relay and EGR
valve connector.
8 CHECK POOR CONTACT.
Check that the poor contact of ECM and EGR
valve connector.Is there poor contact of ECM
and EGR valve connector?Repair the poor
contact portion of
ECM and EGR
valve connector.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a spec-
ified condition at
this time. Step Check Yes No
Page 1263 of 2870
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)”.
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.
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.
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.