2004 SUBARU FORESTER meter

FU(H4DOTC 2.5)-63
FUEL INJECTION (FUEL SYSTEM)
Fuel System Trouble in General
31.Fuel System Trouble in General
A: INSPECTION
NOTE:
 When the vehicle is left unattended for an extended period of time, water may accumulate in the fuel tank.
To prevent water condensation.
(1) Top off the fuel tank or drain the fuel completely.
(2) Drain the water condensation from the fuel filter.
 Refilling the fuel tank.
Refill the fuel tank while there is still some fuel left in the tank.
 Protecting the fuel system against freezing and water condensation.
(3) Cold areas:
In snow-covered areas, mountainous areas, skiing areas, etc. where ambient temperatures drop below
0°C (32°F) throughout the winter season, use an anti-freeze solution in the cooling system. Refueling will
also complement the effect of anti-freeze solution each time the fuel level drops to about one-half. After
the winter season, drain the water which may have accumulated in the fuel filter and fuel tank in the man-
ner same as that described under “Affected areas” below.
(4) Affected areas:
When the water condensation is notched in the fuel filter, drain the water from both the fuel filter and fuel
tank or use a water removing agent (or anti-freeze solution) in the fuel tank.
 Observe the instructions, notes, etc., indicated on the label affixed to the anti-freeze solution (water remov-
ing agent) container before use.
Trouble and possible cause Corrective action
1. Insufficient fuel supply to the injector
1) Fuel pump will not operate.
❍Defective terminal contact.Inspect connections, especially ground, and tighten
securely.
❍Trouble in electromagnetic or electronic circuit parts. Replace the fuel pump.
2) Lowering of fuel pump function. Replace the fuel pump.
3) Clogged dust or water in the fuel filter. Replace the fuel filter, clean or replace fuel tank.
4) Clogged or bent fuel pipe or hose. Clean, correct or replace the fuel pipe or hose.
5) Air is mixed in the fuel system. Inspect or retighten each connection part.
6) Clogged or bent breather tube or pipe. Clean, correct or replace the air breather tube or pipe.
7) Damaged diaphragm of pressure regulator. Replace.
2. Leakage or blow out fuel
1) Loosened joints of the fuel pipe. Retightening.
2) Cracked fuel pipe, hose and fuel tank. Replace.
3) Defective welding part on the fuel tank. Replace.
4) Defective drain packing of the fuel tank. Replace.
5) Clogged or bent air breather tube or air vent tube.Clean, correct or replace the air breather tube or air vent
tube.
3. Gasoline smell inside of compartment
1)Loose joints at air breather tube, air vent tube and fuel filler
pipe.Retightening.
2) Defective packing air tightness on the fuel saucer. Correct or replace the packing.
3) Cracked fuel separator. Replace the separator.
4) Inoperative fuel pump modulator or circuit. Replace.
4. Defective fuel meter indicator
1) Defective operation of fuel level sensor. Replace.
2) Defective operation of fuel meter. Replace.
5. Noise
1) Large operation noise or vibration of fuel pump. Replace.

EN(H4DOTC 2.5)-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 2.5)-
54, 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 2.5)-
258, 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 2.5)-
65, List of Diag-
nostic 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 2.5)-
45, Malfunction In-
dicator Light.>
4 PERFORM THE DIAGNOSIS.
1) Perform clear memory mode. EN(H4DOTC 2.5)-42, Clear Memory Mode.>
2) Perform the “INSPECTION MODE”. to EN(H4DOTC 2.5)-35, 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 2.5)-
70, Diagnostic
Procedure with
Diagnostic Trou-
ble Code (DTC).>Finish the diagno-
sis.

EN(H4DOTC 2.5)-3
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

EN(H4DOTC 2.5)-5
ENGINE (DIAGNOSTIC)
General Description
3. General Description
A: CAUTION
1) Airbag system wiring harness is routed near the
ECM, main relay and fuel pump relay.
CAUTION:
 All airbag system wiring harness and con-
nectors are all colored yellow. Do not use the
electrical test equipment on these circuits.
 Be careful not to damage the Airbag system
wiring harness when servicing the ECM, TCM,
main relay and fuel pump relay.
2) Never connect the battery in reverse polarity.
 The ECM will be destroyed immediately.
 The fuel injector and other part will be damaged.
3) Do not disconnect the battery terminals while the
engine is running.
 A large counter electromotive force will be gener-
ated in the generator, and this voltage may damage
electronic parts such as ECM, etc.
4) Before disconnecting the connectors of each
sensor and the ECM, be sure to turn OFF the igni-
tion switch.
5) Poor contact has been identified as a primary
cause of this problem. Measure the voltage or re-
sistance of individual sensor or all electrical control
modules using a tapered pin with a diameter of less
than 0.64 mm (0.025 in). Do not insert the pin more
than 5 mm (0.20 in) into the part.
6) Remove the ECM from the located position after
disconnecting two cables on battery.
 Otherwise, the ECM may be damaged.
CAUTION:
When replacing the ECM, be careful not to use
the wrong spec. ECM to avoid damaging the
fuel injection system.
7) Connectors to each sensor in the engine com-
partment and the harness connectors on the en-
gine side and body side are all designed to be
waterproof. However, take care not to allow water
to get into the connectors when washing the vehi-
cle, or when servicing the vehicle on a rainy day. 8) Use ECM mounting stud bolts on the body head
grounding point when measuring voltage and resis-
tance inside the passenger compartment.
9) Use engine ground terminal or engine proper as
the grounding point to the body when measuring
voltage and resistance in the engine compartment.
10) Every MFI-related part is a precision part. Do
not drop them.
11) Observe the following cautions when installing
a radio in MFI equipped models.
CAUTION:
 The antenna must be kept as far apart as pos-
sible from the control unit.
(The ECM is located under the steering column,
inside of the instrument panel lower trim panel.)
 The antenna feeder must be placed as far
apart as possible from the ECM and MFI har-
ness.
 Carefully adjust the antenna for correct match-
ing.
 When mounting a large power type radio, pay
special attention to the three items above men-
tioned.
 Incorrect installation of the radio may affect
the operation of the ECM.
12) Before disconnecting the fuel hose, disconnect
the fuel pump connector and crank the engine for
more than five seconds to release pressure in the
fuel system. If engine starts during this operation,
run it until it stops.
(A) Stud bolt
EN-00069
(A)
EN-01201

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)-7
ENGINE (DIAGNOSTIC)
General Description
2. ENGINE AND EMISSION CONTROL SYS-
TEM
 MFI system is a system that supplies the opti-
mum air-fuel mixture to the engine for all the vari-
ous operating conditions through the use of the
latest electronic technology.
With this system fuel, which is pressurized at a con-
stant pressure, is injected into the intake air pas-
sage of the cylinder head. The injection quantity of
fuel is controlled by an intermittent injection system
where the electro-magnetic injection valve (fuel in-
jector) opens only for a short period of time, de-
pending on the quantity of air required for one cycle
of operation. In actual operation, the injection quan-
tity is determined by the duration of an electric sig-nal applied to the fuel injector and this permits
simple, yet highly precise metering of the fuel.
 Further, all the operating conditions of the engine
are converted into electric signals, and this results
in additional features of the system, such as large
improved adaptability, easier addition of compen-
sating element, etc.
The MFI system also has the following features:
 Reduced emission of harmful exhaust gases.
 Reduced in fuel consumption.
 Increased engine output.
 Superior acceleration and deceleration.
 Excellent engine start and warm-up perfor-
mance by the correction of engine coolant tem-
perature and intake air temperature.
D: PREPARATION TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
24082AA230
(Newly adopted tool)CARTRIDGE Troubleshooting for electrical system.
22771AA030 SUBARU SELECT
MONITOR KITTroubleshooting for electrical system.
 English: 22771AA030 (Without printer)
 German: 22771AA070 (Without printer)
 French: 22771AA080 (Without printer)
 Spanish: 22771AA090 (Without printer)
ST24082AA230
ST22771AA030

EN(H4DOTC 2.5)-25
ENGINE (DIAGNOSTIC)
OBD-II General Scan Tool
2. MODE $01 (CURRENT POWERTRAIN DIAGNOSTIC DATA)
Refers to data denoting the current operating condition of analog input/output, digital input/output and/or the
powertrain system.
A list of the support data and PID (Parameter Identification) codes are shown in the following table.
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruction manual to access generic OBD-II PIDs (MODE
$01).
3. MODE $02 (POWERTRAIN FREEZE FRAME DATA)
Refers to data denoting the operating condition when trouble is sensed by the on-board diagnosis system.
A list of the support data and PID (Parameter Identification) codes are shown in the following table.
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruction manual to access freeze frame data (MODE
$02).
PID Data Unit of measure
01Number of emission-related powertrain DTC, malfunction indicator light status and diagnosis
support information—
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim%
07 Long term whole fuel trim%
0B Intake manifold absolute pressure kPa, mmHg
0C Engine revolutionrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
0F Intake air temperature°C
10 Air flow rate of mass air flow sensor g/sec
11 Throttle valve absolute opening angle %
13 Check whether oxygen sensor is installed. —
15 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor V and %
1C Available OBD system—
24 A/F value and A/F sensor output voltage — and V
34 A/F value and A/F sensor current — and mA
PID Data Unit of measure
02 DTC that caused CARB required freeze frame data storage —
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim%
07 Long term whole fuel trim%
0B Intake manifold absolute pressure mmHg
0C Engine speedrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
0F Intake air temperature°C
10 Air flow rate of mass air flow sensor g/sec
11 Throttle valve absolute opening angle %

EN(H4DOTC 2.5)-28
ENGINE (DIAGNOSTIC)
Subaru Select Monitor
4. READ CURRENT DATA FOR ENGINE. (NORMAL MODE)
1) On the «Main Menu» display screen, select the {Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen, select the {Engine} and press the [YES] key.
3) Press the [YES] key after the information of engine type was displayed.
4) On the «Engine Diagnosis» screen, select the {Current Data Display/Save}, and then press the [YES] key.
5) On the «Data Display Menu» screen, select the {Data Display} and press the [YES] key.
6) Using the scroll key, move the display screen up or down until the desired data is shown.
 A list of the support data is shown in the following table.
Remarks Display Unit of measure
Battery voltage Battery Voltage V
Vehicle speed signal Vehicle Speed km/h or MPH
Engine speed signal Engine Speed rpm
Engine coolant temperature signal Coolant Temp.°C or °F
Ignition timing signal Ignition Timing deg
Throttle position signal Throttle Opening Angle %
Injection pulse width Fuel Injection #1 Pulse ms
Fuel pump duty control signal Fuel Pump Duty %
A/F sensor current A/F Sensor #1 Current mA
A/F sensor resistance A/F Sensor #1 ResistanceΩ
Front oxygen (A/F) sensor lambda value A/F Sensor #1 —
Rear oxygen sensor output signalRear O
2 Sensor
V
Short term fuel trim A/F Correction #1 %
Knock sensor compensation Knocking Correction deg
Atmospheric pressure signal Atmosphere Pressure mmHg, kPa, inHg or psi
Intake manifold relative pressure signal Mani. Relative Pressure mmHg, kPa, inHg or psi
Intake manifold absolute pressure signal Mani. Absolute Pressure mmHg, kPa, inHg or psi
A/F correction (short term fuel trim) by rear oxygen sensor A/F Correction #3 %
Long term whole fuel trim A/F Learning #1 %
Canister purge control solenoid valve duty ratio CPC Valve Duty Ratio %
Primary supercharged pressure control signal Primary Control %
Tumble generated valve position sensor signal (RH side) TGV Position Sensor R V
Tumble generated valve position sensor signal (LH side) TGV Position Sensor L V
Acceleration opening angle Accel Opening Angle %
VVT advance angle amount (R) VVT Adv. Amount R deg
VVT advance angle amount (L) VVT Adv. amount L deg
OCV duty R OCV Duty R %
OCV duty L OCV Duty L %
OCV current R OCV current R mA
OCV current L OCV Current L mA
Throttle motor duty Throttle Motor Duty %
Throttle power supply voltage Throttle Motor Voltage V
Sub throttle sensor voltage Sub-Throttle Sensor V
Main throttle sensor voltage Main-Throttle Sensor V
Sub acceleration sensor voltage Sub-Accelerator Sensor V
Main acceleration sensor voltage Main-Accelerator Sensor V
Memory vehicle speed Memorized Cruise Speed km/h
Alternate duty ratio ALT Duty %
Exhaust gas temperature signal Exhaust gas temperature°C
Estimated cumulative driving distance Odd Meter Km
Fuel level signal Fuel Level Voltage V
Intake air temperature signal Intake Air Temp.°C or °F
Mass air flow sensor signal Mass Air Flow g/s