2004 SUBARU FORESTER relay

EN(H4SO)-129
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
W: DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SEN-
SOR 1)
DTC DETECTING CONDITION:
Immediately at fault recognition
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02384
B18
3412
56
B47F44
12345678
B136B135
1234
B21
123
4
56
78
9
1011 12
1314 15 16
SBF-5
EE
B47
B18
6
4
5
3
2
1
B23 C13
C22C6 C17
C16
C5
8
B:
C:B135
B136
B21
E2 ECMBATTERY
B61F44
7
FRONT OXYGEN
(A/F) SENSOR MAIN RELAY
567
82 1
94
310
24
22 23251112131415
26 27
281617181920 21
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
LHDLHD
RHDRHD
4
3
1 2
B: C:

EN(H4SO)-131
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
X: DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (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 ERATION, Clear Memory Mode.> and Inspection Mode tion 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:

EN(H4SO)-134
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Y: DTC P0138 O2 SENSOR CIRCUIT HIGH VOLTAGE (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 ERATION, Clear Memory Mode.> and Inspection Mode tion 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:

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 ERATION, Clear Memory Mode.> and Inspection Mode tion 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:

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 ERATION, Clear Memory Mode.> and Inspection Mode tion 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

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 ERATION, Clear Memory Mode.> and Inspection Mode tion 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

EN(H4SO)-144
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK POWER SUPPLY LINE.
1) Turn the ignition switch to ON.
2) Measure the voltage between fuel injector
and engine ground on faulty cylinders.
Connector & terminal
#1 (E5) No. 2 (+) — Engine ground (
−):
#2 (E16) No. 2 (+) — Engine ground (
−):
#3 (E6) No. 2 (+) — Engine ground (
−):
#4 (E17) No. 2 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair poor con-
tact in all connec-
tors in fuel injector
circuit.Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
main relay and fuel
injector connector
on faulty cylinders
 Poor contact in
coupling connector
 Poor contact in
main relay connec-
tor
 Poor contact in
fuel injector con-
nector on faulty
cylinders
7 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) Turn the ignition switch to ON.
4) Measure the voltage between ECM con-
nector and chassis ground on faulty cylinders.
Connector & terminal
#1 (B134) No. 34 (+) — Chassis ground (
−):
#2 (B134) No. 23 (+) — Chassis ground (
−):
#3 (B134) No. 22 (+) — Chassis ground (
−):
#4 (B134) No. 8 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and fuel
injector. After
repair, replace the
ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 8.
8 CHECK FUEL INJECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between fuel injec-
tor terminals on faulty cylinder.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 1
Ω?Replace the faulty
fuel injector to FU(H4SO)-35,
Fuel Injector.> and
ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>Go to step 9.
9 CHECK INSTALLATION OF CAMSHAFT PO-
SITION SENSOR/CRANKSHAFT POSITION
SENSOR.Is the installation of camshaft
position sensor or crankshaft
position sensor loosened?Tighten camshaft
position sensor or
crankshaft posi-
tion sensor.Go to step 10.
10 CHECK CRANK SPROCKET.
Remove the timing belt cover.Is the crank sprocket rusted or
does it have broken teeth?Replace the crank
sprocket. ME(H4SO)-55,
Crank Sprocket.>Go to step 11.
11 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. ME(H4SO)-48,
Timing Belt.>Go to step 12.
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 replenishing
fuel, Go to step 13. Step Check Yes No

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 ERATION, Clear Memory Mode.> and Inspection Mode tion 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: