ECU 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 1235 of 2870

EN(H4SO)-137
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Z: DTC P0139 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 2)
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode
WIRING DIAGRAM:
EN-02385
BATTERYB61F44
7
B47 MAIN RELAY
12
35
46
B61
12345678
C4B14B19D15
C16C5
REAR
OXYGEN SENSOR
ECM
1432
8B21
B122
T6
E2
B47
T6B21
12 34
56 78
9
10 11 12
13 14 15 16
3456
12
1
B135 B:
D:
B137
SBF-5
C:B136
B122 : LHDB122 : RHDB137
4
1
53
2618 15 167891011
17 19
20121314
B135
567
82
94
310
24 22 23 251112131415
26 27
281617181920 21
B136
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
LHD
LHD
RHD
RHD1 8
4
143
T5
B19
2
B19T5
B122
T5
34
12
LHDLHD
RHDRHD
1234
123456781234
B:
D:C:
Page 1237 of 2870

EN(H4SO)-139
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AB:DTC P0172 SYSTEM TOO RICH (BANK 1)
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Erroneous idling
Engine stalls.
Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode
Step Check Yes No
1 CHECK EXHAUST SYSTEM.Are there holes or loose bolts
on exhaust system?Repair exhaust
system.Go to step 2.
2 CHECK EGR VALVE.Is the EGR valve stuck? Replace the EGR
valve.Go to step 3.
3 CHECK AIR INTAKE SYSTEM.Are there holes, loose bolts or
disconnection of hose on air
intake system?Repair air intake
system.Go to step 4.
4 CHECK PURGE CONTROL SOLENOID
VALVE.Is the purge control solenoid
valve stuck?Replace the purge
control solenoid
valve.Go to step 5.
5 CHECK PCV VALVE.Is the PCV valve stuck? Replace the PCV
valve.Go to step 6.
6 CHECK FUEL PRESSURE.
Warning:
Place “NO FIRE” signs near the working
area.
Be careful not to spill fuel.
1) Release the fuel pressure.
(1) Disconnect the connector from fuel
pump relay.
(2) Start the engine and run it until it stalls.
(3) After the engine stalls, crank it for five
more seconds.
(4) Turn the ignition switch to OFF.
2) Connect the connector to fuel pump relay.
3) Disconnect the fuel delivery hose, and con-
nect the fuel pressure gauge.
4) Install the fuel filler cap.
5) Start the engine and idle while gear posi-
tion is neutral.
6) Measure the fuel pressure while discon-
necting pressure regulator vacuum hose from
intake manifold.
Warning:
Release fuel pressure before removing the
fuel pressure gauge.
NOTE:
If fuel pressure does not increase, squeeze fuel
return hose 2 to 3 times, then measure fuel
pressure again.Is measured value 284 — 314
kPa (2.9 — 3.2 kg/cm
2, 41 —
46 psi)?Go to step 7.Repair the follow-
ing items.
Fuel pressure is
too high:
Clogged fuel
return line or
bent hose
Fuel pressure is
too low:
Improper fuel
pump discharge
Clogged fuel
supply line
Page 1240 of 2870

EN(H4SO)-142
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AF:DTC P0304 CYLINDER 4 MISFIRE DETECTED
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
Immediately at fault recognition (A misfire which could damage catalyst occurs.)
TROUBLE SYMPTOM:
Engine stalls
Erroneous idling
Rough driving
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode
WIRING DIAGRAM:
EN-02383
B21
12345678910111213141516
E6E17
E5E16
12
12121212
2223348
91101112
ECM
B134
E5E16E6E17
B21
E2
FUEL INJECTOR
No. 1FUEL INJECTOR
No. 2FUEL INJECTOR
No. 3FUEL INJECTOR
No. 4
BATTERY
F44B61
SBF-5
B47 MAIN RELAY
12
35
46
B47
34
12
56
F44
12345678
B134
1234567891011121314151617181920212223242526272829303132333435
LHDLHD
RHDRHD
7
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 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 1259 of 2870

EN(H4SO)-161
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AM:DTC P0400 EXHAUST GAS RECIRCULATION FLOW
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Movement performance problem when engine low speed
Erroneous idling
Movement performance problem
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode
WIRING DIAGRAM:
EN-02390
B137
B135
B134
B21
123
4
56
78
9
1011 12
1314 15 16
EE
B47
E18
2 5
1 4 3 6
B21B61F44
E2
B20
E1
B21
E2
6
4
5
3
2
1
1
5 A17 A16 A15 A18
B21 D14A74
3 6
15
16
SBF-5BATTERY MEIN RELAY
EGR
VALVE
A:
B134
B:
B135
D:
B137ECM
B47
F44
E18
3412
56
13
45627
12345678
4
1
53
2618 15 167891011
17 19
20121314
567
82 1
94
310
24 22 23 251112131415
26 27
281617181920 21
1234567891011121314151617181920212223242526272829303132333435
B20
LHDLHD
RHDRHD
A: B:
D: