2004 SUBARU FORESTER fuse

EN(H4DOTC)-53
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 17 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 4.Go to step 2.
2 CHECK POOR CONTACT.Does the malfunction indicator
light come on when shaking or
pulling the ECM connector and
harness?Repair the poor
contact in ECM
connector.Go to step 3.
3 CHECK ECM CONNECTOR.Is the ECM connector correctly
connected?Replace the ECM.
FU(H4DOTC)-50,
Engine Control
Module (ECM).>Repair the con-
nection of ECM
connector.
4 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Remove the combination meter. IDI-10, Combination Meter Assembly.>
3) Disconnect the connector from ECM and
combination meter.
4) Measure the resistance of harness
between ECM and combination meter connec-
tor.
Connector & terminal
(B134) No. 17 — (i12) No. 1:Is the resistance less than 1
Ω?Go to step 5.Repair the har-
ness and connec-
tor.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and combi-
nation meter con-
nector
 Poor contact in
coupling connector
5 CHECK POOR CONTACT.
Check poor contact in combination meter con-
nector.Is there poor contact in combi-
nation meter connector?Repair poor con-
tact in combination
meter connector.Go to step 6.
6 CHECK HARNESS BETWEEN COMBINA-
TION METER AND IGNITION SWITCH CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i10) No. 9 (+) — Chassis ground (
−):Is the voltage more than 10 V? Replace the board
of combination
meter. 10, Combination
Meter Assembly.>Check the follow-
ing and repair if
necessary.
N
OTE:
 Blown out of
fuse (No. 14)
 Open or short
circuit in harness
between fuse (No.
14) and battery
terminal
 Poor contact in
ignition switch con-
nector

EN(H4DOTC)-61
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
Step Check Yes No
1 CHECK OPERATION OF STARTER MOTOR.Does the starter motor oper-
ate?Go to step 2.Go to step 3.
2 CHECK DTC.Is DTC displayed? EN(H4DOTC)-39, OPERA-
TION, Read Diagnostic Trouble
Code (DTC).>Inspect the rele-
vant DTC using
List of Diagnostic
Trouble Code
(DTC). EN(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).>Go to step 3.
3 CHECK INPUT SIGNAL FOR STARTER MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from starter
motor.
3) Turn the ignition switch to START.
4) Measure the power supply voltage between
starter motor connector terminal and engine
ground.
Connector & terminal
(B14) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 4.Go to step 5.
4 CHECK GROUND CIRCUIT OF STARTER
MOTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of ground cable
between ground cable terminal and engine
ground.Is the resistance less than 5
Ω?Check the starter
motor. SC(H4SO)-6,
Starter.>Repair open circuit
of ground cable.
5 CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition
switch.
3) Measure the power supply voltage between
ignition switch connector and chassis ground.
Connector & terminal
(B72) No. 1 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 6.Check the follow-
ing and repair if
necessary.
 Brown out
fuse
 Open circuit
in harness
between igni-
tion switch and
battery.
6 CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1) Connect the connector to ignition switch.
2) Turn the ignition switch to START.
3) Measure the voltage between ignition
switch and chassis ground.
Connector & terminal
(B72) No. 3 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair open circuit
between ignition
switch and starter
motor circuit.Go to step 7.
7 CHECK POOR CONTACT.
Check poor contact in ignition switch connec-
tor.Is there poor contact in ignition
switch connector?Repair poor con-
tact in ignition
switch connector.Replace the igni-
tion switch.

EN(H4DOTC)-234
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector.
3) Turn the ignition switch to ON.
4) While operating the radiator fan relay, mea-
sure voltage between ECM terminal and
ground.
N
OTE:
Radiator fan relay operation can be executed
using Subaru Select Monitor.For procedure, re-
fer to “Compulsory Valve Operation Check
Mode”. Valve Operation Check Mode.>
Connector & terminal
(B135) No. 24 (+) — Chassis ground (
−):
(B135) No. 25 (+) — Chassis ground (
−):Does the voltage vary between
0 — 10 V?Repair the poor
contact in ECM
connector.Go to step 2.
2 CHECK GROUND SHORT CIRCUIT IN RADI-
ATOR FAN RELAY CONTROL CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B135) No. 24 — Chassis ground:
(B135) No. 25 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in
radiator fan relay
control circuit.
3 CHECK POWER SUPPLY FOR RELAY.
1) Remove the main fan relay 1 and sub fan
relay from A/C relay holder.
2) Turn the ignition switch to ON.
3) Measure the voltage between fuse and
relay box (F/B) connector and chassis ground.
Connector & terminal
(F27) No. 25 (+) — Chassis ground (
−):
(F27) No. 34 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Repair open circuit
in harness
between ignition
switch and fuse
and relay box (F/B)
connector.
4 CHECK MAIN FAN RELAY 1.
1) Turn the ignition switch to OFF.
2) Measure the resistance of main fan relay 1
terminals.
Te r m i n a l s
No. 32 — No. 34:Is the resistance 87 — 107 Ω? Go to step 5.Replace the main
fan relay 1.
5 CHECK SUB FAN RELAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between sub fan
relay terminals.
Te r m i n a l s
No. 25 — No. 27:Is the resistance 87 — 107 Ω? Go to step 6.Replace the sub
fan relay.
6 CHECK OPEN CIRCUIT IN FAN RELAY
CONTROL CIRCUIT.
Measure the resistance of harness between
ECM and fan relay connector.
Connector & terminal
(B135) No. 24 — (F27) No. 27:
(B135) No. 25 — (F27) No. 32:Is the resistance less than 1
Ω?Go to step 7.Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and fan relay
connector
 Poor contact in
coupling connector

EN(H4DOTC)-286
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B135) No. 19 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair the poor
contact in ECM
connector.Go to step 2.
2 CHECK HARNESS BETWEEN ECM AND
MAIN FUSE BOX CONNECTOR.
1) Disconnect the connector from ECM.
2) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B135) No. 19 — Chassis ground:Is the resistance less than 10
Ω?Repair ground
short circuit in har-
ness between
ECM connector
and battery termi-
nal.Go to step 3.
3 CHECK FUSE SBF-5.Is the fuse blown out? Replace the fuse. Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and battery
 Poor contact in
ECM connector.
 Poor contact in
battery terminal

EN(H4DOTC 2.5)-6
ENGINE (DIAGNOSTIC)
General Description
13) Diagnostics should be conducted by rotating
with simple, easy operations and proceeding to
complicated, difficult operations. The most impor-
tant thing in diagnostics is to understand the cus-
tomer’s complaint, and distinguish between the
three causes.
14) On the model with ABS, when performing driv-
ing test in jacked-up or lifted-up position, some-
times the warning light may be lit, but this is not a
malfunction of the system. The reason for this is the
speed difference between the front and rear
wheels. After diagnosis of engine control system,
perform the ABS memory clearance procedure of
self-diagnosis function.
B: INSPECTION
Before performing diagnostics, check the following
items which might affect engine problems:
1. BATTERY
1) Measure battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V
Specific gravity: Above 1.260
2) Check the condition of the main and other fuses,
and harnesses and connectors. Also check for
proper grounding.
2. ENGINE GROUND
Make sure the engine ground terminal is properly
connected to the engine.
C: NOTE
1. GENERAL DESCRIPTION
 On-board diagnosis (OBD) system detects and
indicates a fault in various inputs and outputs of the
complex electronic control. Malfunction indicator
light in the combination meter indicates occurrence
of a fault or trouble.
 Further, against such a failure or sensors as may
disable the drive, the fail-safe function is provided
to ensure the minimal driveability.
 The OBD system incorporated with the vehicles
within this engine family complies with Section
1968.1, California Code of Regulations (OBD-II
regulation). The OBD system monitors the compo-
nents and the system malfunction listed in Engine
Section which affects on emissions.
 When the system decides that a malfunction oc-
curs, malfunction indicator light illuminates. At the
same time of the malfunction indicator light illumi-
nation or blinking, the DTC and a freeze frame en-
gine conditions are stored into on-board computer.
 The OBD system stores freeze frame engine
condition data (engine load, engine coolant tem-
perature, fuel trim, engine speed and vehicle
speed, etc.) into on-board computer when it detects
a malfunction first.
 If the OBD system detects the various malfunc-
tions including the fault of fuel trim or misfire, the
OBD system first stores freeze frame engine condi-
tions about the fuel trim or misfire.
 When the malfunction does not occur again for
three consecutive driving cycles, malfunction indi-
cator light is turned off, but DTC remains at on-
board computer.
 The OBD-II system is capable of communication
with a general scan tool (OBD-II general scan tool)
formed by ISO 9141 CARB.
 The OBD-II diagnostics procedure is different
from the usual diagnosis procedure. When trouble-
shooting the OBD-II models, connect Subaru Se-
lect Monitor or the OBD-II general scan tool to the
vehicle.
EN-01201

EN(H4DOTC 2.5)-48
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 17 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 4.Go to step 2.
2 CHECK POOR CONTACT.Does the malfunction indicator
light come on when shaking or
pulling the ECM connector and
harness?Repair the poor
contact in ECM
connector.Go to step 3.
3 CHECK ECM CONNECTOR.Is the ECM connector correctly
connected?Replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Repair the con-
nection of ECM
connector.
4 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Remove the combination meter. IDI-10, Combination Meter Assembly.>
3) Disconnect the connector from ECM and
combination meter.
4) Measure the resistance of harness between
ECM and combination meter connector.
Connector & terminal
(B134) No. 17 — (i12) No. 1:Is the resistance less than 1
Ω?Go to step 5.Repair the harness
and connector.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and combi-
nation meter con-
nector
 Poor contact in
coupling connector
5 CHECK POOR CONTACT.
Check poor contact in combination meter con-
nector.Is there poor contact in combi-
nation meter connector?Repair poor con-
tact in combination
meter connector.Go to step 6.
6 CHECK HARNESS BETWEEN COMBINA-
TION METER AND IGNITION SWITCH CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i10) No. 9 (+) — Chassis ground (
−):Is the voltage more than 10 V? Replace the board
of combination
meter. 10, Combination
Meter Assembly.>Check the follow-
ing and repair if
necessary.
N
OTE:
 Blown out of
fuse (No. 14)
 Open or short
circuit in harness
between fuse (No.
14) and battery
terminal
 Poor contact in
ignition switch con-
nector

EN(H4DOTC 2.5)-56
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
Step Check Yes No
1 CHECK BATTERY.
Check the battery voltage.Is the voltage more than 12 V? Go to step 2.Charge or replace
the battery.
2 CHECK OPERATION OF STARTER MOTOR.Does the starter motor oper-
ate?Check ECM power
supply and ground
line. EN(H4DOTC 2.5)-
57, CHECK
POWER SUPPLY
AND GROUND
LINE OF ENGINE
CONTROL MOD-
ULE (ECM), Diag-
nostics for Engine
Starting Failure.>Go to step 3.
3 CHECK INPUT SIGNAL FOR STARTER MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from starter
motor.
3) Turn the ignition switch to START.
4) Measure the power supply voltage between
starter motor connector terminal and engine
ground.
Connector & terminal
(B14) No. 1 (+) — Engine ground (
−):
NOTE:
 For AT model, shift the select lever to “P” or
“N” range.
 For MT model, depress the clutch pedal.Is the voltage more than 10 V? Go to step 4.Go to step 5.
4 CHECK GROUND CIRCUIT OF STARTER
MOTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the terminal from starter motor.
3) Measure the resistance of ground cable
between ground cable terminal and engine
ground.Is the resistance less than 5
Ω?Check the starter
motor. SC(H4SO)-6,
Starter.>Repair open circuit
of ground cable.
5 CHECK HARNESS BETWEEN BATTERY
AND IGNITION SWITCH CONNECTOR.
1) Disconnect the connector from ignition
switch.
2) Measure the power supply voltage between
ignition switch connector and chassis ground.
Connector & terminal
(B72) No. 1 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 6.Repair open circuit
in harness
between ignition
switch and bat-
tery, and check
fuse SBF No. 4
and SBF No. 1.
6 CHECK IGNITION SWITCH.
1) Disconnect the connector from ignition
switch.
2) Measure the resistance between ignition
switch terminals while turning the ignition
switch to START.
Te r m i n a l s
No. 1 — No. 3:Is the resistance less than 5
Ω?Repair the poor
contact in ignition
switch.Replace the igni-
tion switch.

EN(H4DOTC 2.5)-175
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector.
3) Turn the ignition switch to ON.
4) While operating the radiator fan relay, mea-
sure voltage between ECM terminal and ground.
N
OTE:
Radiator fan relay operation can be executed
using Subaru Select Monitor. For procedure,
refer to “Compulsory Valve Operation Check
Mode”. Select Monitor.>
Connector & terminal
(B135) No. 24 (+) — Chassis ground (
−):
(B135) No. 25 (+) — Chassis ground (
−):Does the voltage vary between
0 — 10 V?Repair the poor
contact in ECM
connector.Go to step 2.
2 CHECK GROUND SHORT CIRCUIT IN RADI-
ATOR FAN RELAY CONTROL CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B135) No. 24 — Chassis ground:
(B135) No. 25 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in
radiator fan relay
control circuit.
3 CHECK POWER SUPPLY FOR RELAY.
1) Remove the main fan relay and sub fan relay
from A/C relay holder.
2) Turn the ignition switch to ON.
3) Measure the voltage between fuse and
relay box (F/B) connector and chassis ground.
Connector & terminal
(F27) No. 27 (+) — Chassis ground (
−):
(F27) No. 32 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Repair open circuit
in harness
between ignition
switch and fuse
and relay box (F/B)
connector.
4 CHECK FAN RELAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between fan relay
terminals.
Te r m i n a l s
No. 32 — No. 34 (Main fan relay)
No. 25 — No. 27 (Sub fan relay)Is the resistance 87 — 107 Ω? Go to step 5.Replace the fan
relay.
5 CHECK OPEN CIRCUIT IN FAN RELAY
CONTROL CIRCUIT.
Measure the resistance of harness between
ECM and fan relay connector.
Connector & terminal
(B135) No. 24 — (F27) No. 27:
(B135) No. 25 — (F27) No. 32:Is the resistance less than 1
Ω?Go to step 6.Repair harness
and connector.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and fan relay
connector
 Poor contact in
coupling connector
6 CHECK POOR CONTACT.
Check poor contact in ECM or fan relay connector.Is there poor contact in ECM or
fan relay connector?Repair the poor
contact in ECM or
fan relay connector.Contact the SUB-
ARU dealer.