2004 SUBARU FORESTER engine

IG(H4DOTC)-5
IGNITION
Spark Plug
2. Spark Plug
A: REMOVAL
CAUTION:
All spark plugs installed on an engine, must be
of the same heat range. General Description.>
1. RH SIDE
1) Disconnect the ground cable from battery.
2) Remove the air cleaner lower case. IN(H4DOTC)-7, REMOVAL, Air Cleaner.>
3) Disconnect the connector from ignition coil.
4) Remove the ignition coil.5) Remove the spark plugs with the spark plug
sockets.
2. LH SIDE
1) Disconnect the battery cables, and then remove
the battery and battery carrier.
2) Disconnect the washer motor connector.
3) Disconnect the rear window glass washer hose
from washer motor, then plug connection with a
suitable cap.
4) Remove the two bolts which hold washer tank,
then take the tank away from working area.
FU-00009
FU-01307
IG-00003
IG-00004
FU-00009
IG-00005
IG-00006

IG(H4DOTC)-7
IGNITION
Spark Plug
2) Carbon fouled:
Dry fluffy carbon deposits on insulator and elec-
trode are mostly caused by slow speed driving in
city, weak ignition, too rich fuel mixture, dirty air
cleaner, etc.
It is advisable to replace with plugs having hotter
heat range.
3) Oil fouled:
Wet black deposits show excessive oil entrance
into combustion chamber through worn rings and
pistons or excessive clearance between valve
guides and stems. If the same condition remains
after repair, use a hotter plug.
4) Overheating:
White or light gray insulator with black or gray
brown spots and bluish burnt electrodes indicates
engine overheating. Moreover, the appearance re-
sults from incorrect ignition timing, loose spark
plugs, wrong selection of fuel, hotter range plug,
etc. It is advisable to replace with plugs having
colder heat range.D: ADJUSTMENT
Clean the spark plugs with a wire brush. Clean and
remove the carbon or oxide deposits, but do not
wear ceramic insulator.
If deposits are too stubborn, replace the plugs.
After cleaning the spark plugs, correct the spark
plug gap using a gap gauge.
NOTE:
Do not use spark plug cleaners, because the spark
plugs are applied with platinum or irigium tips.
Spark plug gap: L
0.7 — 0.8 mm (0.028 — 0.031 in)
NOTE:
Replace with a new spark plug if this area (A) is
worn to “ball” shape.
IG-00012
IG-00013
IG-00014
IG-00015
L
(A)

FUJI HEAVY INDUSTRIES LTD. G8080GE3
2004 FORESTER SERVICE MANUAL QUICK REFERENCE INDEX
ENGINE SECTION 2
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.FUEL INJECTION (FUEL SYSTEM) FU(H4DOTC)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICE)EC(H4DOTC)
INTAKE (INDUCTION) IN(H4DOTC)
MECHANICAL ME(H4DOTC)
EXHAUST EX(H4DOTC)
COOLING CO(H4DOTC)
LUBRICATION LU(H4DOTC)
SPEED CONTROL SYSTEM SP(H4DOTC)
IGNITION IG(H4DOTC)
STARTING/CHARGING SYSTEM SC(H4DOTC)
ENGINE (DIAGNOSTIC) EN(H4DOTC)

FUJI HEAVY INDUSTRIES LTD. G8080GE3
2004 FORESTER SERVICE MANUAL QUICK REFERENCE INDEX
ENGINE SECTION 2
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.FUEL INJECTION (FUEL SYSTEM) FU(H4DOTC)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICE)EC(H4DOTC)
INTAKE (INDUCTION) IN(H4DOTC)
MECHANICAL ME(H4DOTC)
EXHAUST EX(H4DOTC)
COOLING CO(H4DOTC)
LUBRICATION LU(H4DOTC)
SPEED CONTROL SYSTEM SP(H4DOTC)
IGNITION IG(H4DOTC)
STARTING/CHARGING SYSTEM SC(H4DOTC)
ENGINE (DIAGNOSTIC) EN(H4DOTC)

ENGINE (DIAGNOSTIC)
EN(H4DOTC)
Page
1. Basic Diagnostics Procedure ......................................................................2
2. Check List for Interview ...............................................................................4
3. General Description ....................................................................................6
4. Electrical Component Location ...................................................................9
5. Engine Control Module (ECM) I/O Signal .................................................23
6. Engine Condition Data ..............................................................................27
7. Transmission Control Module (TCM) I/O Signal .......................................28
8. Data Link Connector .................................................................................29
9. OBD-II General Scan Tool ........................................................................30
10. Subaru Select Monitor...............................................................................33
11. Read Diagnostic Trouble Code (DTC) ......................................................39
12. Inspection Mode ........................................................................................40
13. Drive Cycle ................................................................................................45
14. Clear Memory Mode..................................................................................47
15. Compulsory Valve Operation Check Mode ...............................................48
16. Malfunction Indicator Light ........................................................................50
17. Diagnostics for Engine Starting Failure .....................................................59
18. List of Diagnostic Trouble Code (DTC) .....................................................74
19. Diagnostic Procedure with Diagnostic Trouble Code (DTC) .....................80
20. General Diagnostic Table........................................................................295

EN(H4DOTC)-2
ENGINE (DIAGNOSTIC)
Basic Diagnostics Procedure
1. Basic Diagnostics Procedure
A: PROCEDURE
1. ENGINE
Step Check Yes No
1 CHECK ENGINE START FAILURE.
1) Ask the customer when and how the trou-
ble occurred using the interview check list.
Check List for Interview.>
2) Start the engine.Does the engine start? Go to step 2.Inspection using
“Diagnostics for
Engine Start Fail-
ure”. EN(H4DOTC)-59,
Diagnostics for
Engine Starting
Fai lu r e.>
2 CHECK ILLUMINATION OF MALFUNCTION
INDICATOR LIGHT.Does malfunction indicator
light illuminate?Go to step 3.Inspection using
“General Diagnos-
tic Table”. EN(H4DOTC)-
295, General Diag-
nostic Table.>
3 CHECK INDICATION OF DTC ON DISPLAY.
1) Turn the ignition switch to OFF.
2) Connect the Subaru Select Monitor or the
OBD-II general scan tool to data link connec-
tor.
3) Turn the ignition switch to ON and the Sub-
aru Select Monitor or OBD-II general scan tool
switch to ON.
4) Read the DTC on the Subaru Select Moni-
tor or OBD-II general scan tool.Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC?Record the
DTC.Repair the
trouble cause.
EN(H4DOTC)-74,
List of Diagnostic
Trouble Code
(DTC).> Go to
step 4.Repair the related
parts.
N
OTE:
If DTC is not shown
on display although
the malfunction in-
dicator light illumi-
nates, perform the
diagnostics for mal-
function indicator
light circuit or com-
bination meter.
EN(H4DOTC)-50,
Malfunction Indica-
tor Light.>
4 PERFORM THE DIAGNOSIS.
1) Perform clear memory mode. EN(H4DOTC)-47, Clear Memory Mode.>
2) Perform the “INSPECTION MODE”. to EN(H4DOTC)-40, Inspection Mode.>Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC?Check on “Diag-
nostic Chart with
Diagnostic Trou-
ble Code (DTC)”
EN(H4DOTC)-80,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>Finish the diagno-
sis.

EN(H4DOTC)-3
ENGINE (DIAGNOSTIC)
Basic Diagnostics Procedure
2. AUTOMATIC TRANSMISSION
When the DTC about automatic transmission is
shown on display, carry out the following basic
check.After that, carry out the replacement or re-
pair work.
1) ATF level check Transmission Fluid.>
2) Differential gear oil level check Differential Gear Oil.>
3) ATF leak check Transmission Fluid.>
4) Differential gear oil leak check Differential Gear Oil.>
5) Stall Test
6) Line Pressure Test sure Test.>
7) Transfer Clutch Pressure Test Transfer Clutch Pressure Test.>
8) Time Lag Test
9) Road Test
10) Shift characteristics Clutch Pressure Test.>

EN(H4DOTC)-4
ENGINE (DIAGNOSTIC)
Check List for Interview
2. Check List for Interview
A: INSPECTION
1. CHECK LIST NO. 1
Check the following items when problem has occurred.
NOTE:
Use copies of this page for interviewing customers.
Customer’s name Engine No.
Date of sale Fuel brand
Date of repair
Odometer readingkm
V.I.N.miles
Weather❏ Fine
❏ Cloudy
❏ Rainy
❏ Snowy
❏ Va r i o u s / O t h e r s :
Ambient air temperature°C (°F)
❏ Hot
❏ War m
❏ Cool
❏ Cold
Place❏ Highway
❏ Suburbs
❏ Inner city
❏ Uphill
❏ Downhill
❏ Rough road
❏ Others:
Engine temperature❏ Cold
❏ War ming-up
❏ After warming-up
❏ Any temperature
❏ Others:
Engine speed rpm
Vehicle speed km/h (MPH)
Driving conditions❏ Not affected
❏ At starting
❏ While idling
❏ At racing
❏ While accelerating
❏ While cruising
❏ While decelerating
❏ While turning (RH/LH)
Headlight❏ ON / ❏ OFF Rear defogger❏ ON / ❏ OFF
Blower❏ ON / ❏ OFF Radio❏ ON / ❏ OFF
A/C compressor❏ ON / ❏ OFF CD/Cassette❏ ON / ❏ OFF
Radiator fan❏ ON / ❏ OFF Car phone❏ ON / ❏ OFF
Fr o nt wi pe r❏ ON / ❏ OFF CB❏ ON / ❏ OFF
Rear Wiper❏ ON / ❏ OFF