2004 SUBARU FORESTER ignition

EN(H4DOTC 2.5)-58
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
Step Check Yes No
1 CHECK MAIN RELAY.
1) Turn the ignition switch to OFF.
2) Remove the main relay.
3) Connect the battery to main relay terminals
No. 1 and No. 2.
4) Measure the resistance between main relay
terminals.
Te r m i n a l s
No. 3 — No. 5:
No. 4 — No. 6:Is the resistance less than 10
Ω?Go to step 2.Replace the main
relay.
2 CHECK GROUND CIRCUIT FOR ECM.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B134) No. 6 — Chassis ground:
(B134) No. 7 — Chassis ground:
(B134) No. 34 — Chassis ground:
(B135) No. 1 — Chassis ground:
(B135) No. 4 — Chassis ground:
(B135) No. 12 — Chassis ground:
(B137) No. 1 — Chassis ground:
(B137) No. 2 — Chassis ground:
(B137) No. 7 — Chassis ground: Is the resistance less than 5
Ω?Go to step 3.Repair open circuit
in harness
between ECM con-
nector and engine
ground terminal.
3 CHECK INPUT VOLTAGE OF ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 19 (+) — Chassis ground (
−):
(B137) No. 14 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Repair open or
ground short cir-
cuit of power sup-
ply circuit.
4 CHECK INPUT VOLTAGE OF MAIN RELAY.
Measure the voltage between main relay con-
nector and chassis ground.
Connector & terminal
(B47) No. 1 (+) — Chassis ground (
−):
(B47) No. 5 (+) — Chassis ground (
−):
(B47) No. 6 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 5.Repair open or
ground short circuit
in harness of power
supply circuit.
5 CHECK INPUT VOLTAGE OF ECM.
1) Connect the main relay connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 5 (+) — Chassis ground (
−):
(B135) No. 6 (+) — Chassis ground (
−):
(B137) No. 16 (+) — Chassis ground (
−):Is the voltage more than 10 V? Check ignition
control system.
EN(H4DOTC 2.5)-
59, IGNITION
CONTROL SYS-
TEM, Diagnostics
for Engine Start-
ing Failure.>Repair open or
ground short circuit
in harness
between ECM con-
nector and main
relay connector.

EN(H4DOTC 2.5)-59
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
D: IGNITION CONTROL SYSTEM
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02357
IGNITION
SWITCH
SBF-4SBF-1
B72
B135
18
17
16
15
ECM
No.11
E
E
41
E2 B21
E31
E31
E32
E33
E34IGNITION COIL
No.1IGNITION COIL
No.2IGNITION COIL
No.3IGNITION COIL
No.4
E32E33E34
123
123
4
56
78
9
1011 12
1314 15 16
B21B135B72
34
12
3
1
23
1
2
5 4
6
7
8
3
1
23
1
2
567
82 1
94 310
24 22 23 2511 12 13 14 15
26 27
2816 17 18 19
20 21
29 30 31 32 33 34 35
BATTERY

EN(H4DOTC 2.5)-60
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
Step Check Yes No
1 CHECK SPARK PLUG CONDITION.
1) Remove the spark plug. IG(H4DOTC)-6, INSTALLATION, Spark Plug.>
2) Check the spark plug condition. IG(H4DOTC)-6, INSPECTION, Spark Plug.>Is the spark plug’s status OK? Go to step 2.Replace the spark
plug.
2 CHECK IGNITION SYSTEM FOR SPARKS.
1) Connect the spark plug to ignition coil.
2) Release the fuel pressure. FU(H4DOTC 2.5)-45, RELEASING OF FUEL
PRESSURE, OPERATION, Fuel.>
3) Contact the spark plug’s thread portion on
engine.
4) While opening the throttle valve fully, crank
the engine to check that spark occurs at each
cylinder.Does spark occur at each cyl-
inder?Check fuel pump
system. EN(H4DOTC 2.5)-
62, FUEL PUMP
CIRCUIT, Diag-
nostics for Engine
Starting Failure.>Go to step 3.
3 CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL & IGNITOR ASSY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil
& ignitor ASSY.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
ignition coil & ignitor ASSY connector and
engine ground.
Connector & terminal
(E31) No. 3 (+) — Engine ground (
−):
(E32) No. 3 (+) — Engine ground (
−):
(E33) No. 3 (+) — Engine ground (
−):
(E34) No. 3 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 4.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ignition coil & igni-
tor ASSY, and igni-
tion switch
connector
 Poor contact in
coupling connector
4 CHECK HARNESS OF IGNITION COIL & IG-
NITOR ASSY GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ignition
coil & ignitor ASSY connector and engine
ground.
Connector & terminal
(E31) No. 2 — Engine ground:
(E32) No. 2 — Engine ground:
(E33) No. 2 — Engine ground:
(E34) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 5.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ignition coil & igni-
tor ASSY connec-
tor and engine
ground terminal
5 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connector from ignition coil
& ignitor ASSY.
4) Measure the resistance of harness
between ECM and ignition coil & ignitor ASSY
connector.
Connector & terminal
(B135) No. 15 — (E34) No. 1:
(B135) No. 16 — (E33) No. 1:
(B135) No. 17 — (E32) No. 1:
(B135) No. 18 — (E31) No. 1:Is the resistance less than 1
Ω?Go to step 6.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
 OPEN CIR-
CUIT IN HAR-
NESS BETWEEN
ECM AND IGNI-
TION COIL &
IGNITOR ASSY
CONNECTOR.
 Poor contact in
coupling connector

EN(H4DOTC 2.5)-61
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
6 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
Measure the resistance of harness between
ECM and engine ground.
Connector & terminal
(B135) No. 15 — Engine ground:
(B135) No. 16 — Engine ground:
(B135) No. 17 — Engine ground:
(B135) No. 18 — Engine ground:Is the resistance more than 1
MΩ?Go to step 7.Repair ground
short circuit in har-
ness between
ECM and ignition
coil & ignitor ASSY
connector.
7 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Check fuel pump
circuit. EN(H4DOTC 2.5)-
62, FUEL PUMP
CIRCUIT, Diag-
nostics for Engine
Starting Failure.> Step Check Yes No

EN(H4DOTC 2.5)-62
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
E: FUEL PUMP CIRCUIT
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
Step Check Yes No
1 CHECK OPERATING SOUND OF FUEL
PUMP.
Make sure that fuel pump is in operation for two
seconds when turning the ignition switch to ON.
NOTE:
Fuel pump operation check can also be execut-
ed using Subaru Select Monitor.
For the procedure, refer to “Compulsory Valve
Operation Check Mode”. 2.5)-43, Compulsory Valve Operation Check
Mode.>Does the fuel pump produce
operating sound?Check the fuel
injector circuit.
EN(H4DOTC 2.5)-
63, FUEL INJEC-
TOR CIRCUIT,
Diagnostics for
Engine Starting
Fa il u r e. >Display DTC.
EN(H4DOTC 2.5)-
34, OPERATION,
Read Diagnostic
Trouble Code
(DTC).>
EN-02358
R15
E
E M
R122: B135 B
: B137
D
R58
B97 B97
3412
B98 R1
R15
R57
567
82 1
94 310
24 22 23 2511 12 13 14 15
26 27
2816 17 18 19
20 21
29 30 31 32 33 34 35567
82 1
94 310
22 23 11 12 13 14 15
24 25
2616 17
18 19 20 21
27 28 29 30 31
R122
3
4 12
5891067
FUEL PUMP
CONTROL MODULE
FUEL PUMPECMBATTERY
B72SBF-1
SBF-4
D28
B27
E
98 10
7
6 1
4 1
415
14
1 4
5
IGNITION SWITCH
B46 FUEL PUMP
RELAY
2
1 4
3SBF-5
No.118B98
R2
12345678219
32
1234
5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25
: B135
B: B137
D
B72
3412
R58
23
56 1
4

EN(H4DOTC 2.5)-64
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
2 CHECK POWER SUPPLY TO EACH FUEL
INJECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel injector.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
fuel injector terminal and engine ground.
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? Go to step 3.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
main relay and fuel
injector connector
 Poor contact in
main relay connec-
tor
 Poor contact in
coupling connector
 Poor contact in
fuel injector con-
nector
3 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness
between ECM and fuel injector connector.
Connector & terminal
(B136) No. 6 — (E5) No. 1:
(B136) No. 5 — (E16) No. 1:
(B136) No. 4 — (E6) No. 1:
(B136) No. 3 — (E17) No. 1:Is the resistance less than 1
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
ECM and fuel
injector connector
 Poor contact in
coupling connector
4 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
Measure the resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B136) No. 3 — Chassis ground:
(B136) No. 4 — Chassis ground:
(B136) No. 5 — Chassis ground:
(B136) No. 6 — Chassis ground:Is the resistance less than 1
Ω?Repair ground
short circuit in har-
ness between
ECM and fuel
injector connector.Go to step 5.
5 CHECK EACH FUEL INJECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between each fuel
injector terminals.
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.
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Inspection using
“General Diagnos-
tic Table”. EN(H4DOTC 2.5)-
258, INSPEC-
TION, General
Diagnostic Table.> Step Check Yes No

EN(H4DOTC 2.5)-71
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK POWER SUPPLY TO FRONT OXY-
GEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between front oxygen
(A/F) sensor connector and engine ground.
Connector & terminal
(B262) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 2.Repair the power
supply line.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
main relay and
front oxygen (A/F)
sensor connector
 Poor contact in
front oxygen (A/F)
sensor connector
 Poor contact in
main relay connec-
tor
2 CHECK GROUND CIRCUIT FOR ECM.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 6 — Chassis ground:
(B134) No. 7 — Chassis ground:Is the resistance less than 5
Ω?Go to step 3.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and engine
ground cable
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
3 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of front oxygen (A/F) sensor
heater current 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”. 2.5)-27, Subaru Select Monitor.>
 OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the current more than 0.2 A? Repair poor con-
tact connector.
N
OTE:
In this case repair
the following:
 Poor contact in
front oxygen (A/F)
sensor connector
 Poor contact in
ECM connector.Go to step 4.
4 CHECK OUTPUT SIGNAL FROM ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 2 (+) — Chassis ground (
−):
(B134) No. 3 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 6.Go to step 5.
5 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 2 (+) — Chassis ground (
−):
(B134) No. 3 (+) — Chassis ground (
−):Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with voltage
meter?Repair the poor
contact in ECM
connector.Go to step 6.

EN(H4DOTC 2.5)-72
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK FRONT OXYGEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between front oxy-
gen (A/F) sensor connector terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 10
Ω?Repair the harness
and connector.
N
OTE:
In this case repair
the following:
 Open or ground
short circuit in har-
ness between front
oxygen (A/F) sen-
sor and ECM con-
nector
 Poor contact in
front oxygen (A/F)
sensor connector
 Poor contact in
ECM connector.Replace the front
oxygen (A/F) sen-
sor. FU(H4DOTC 2.5)-
36, Front Oxygen
(A/F) Sensor.> Step Check Yes No