ABS SUBARU FORESTER 2004 Service User Guide

FUEL INJECTION (FUEL SYSTEM)
FU(H4SO)
Page
1. General Description ....................................................................................2
2. Throttle Body .............................................................................................13
3. Intake Manifold ..........................................................................................14
4. Engine Coolant Temperature Sensor........................................................25
5. Crankshaft Position Sensor.......................................................................26
6. Camshaft Position Sensor.........................................................................27
7. Knock Sensor ............................................................................................28
8. Throttle Position Sensor ............................................................................29
9. Manifold Absolute Pressure Sensor ..........................................................31
10. Intake Air Temperature Sensor .................................................................32
11. Idle Air Control Solenoid Valve .................................................................33
12. EGR Valve ................................................................................................34
13. Fuel Injector ..............................................................................................35
14. Front Oxygen (A/F) Sensor .......................................................................40
15. Rear Oxygen Sensor.................................................................................42
16. Engine Control Module (ECM) ..................................................................44
17. Main Relay ................................................................................................45
18. Fuel Pump Relay.......................................................................................46
19. Fuel ...........................................................................................................47
20. Fuel Tank ..................................................................................................48
21. Fuel Filler Pipe ..........................................................................................51
22. Fuel Pump .................................................................................................55
23. Fuel Level Sensor .....................................................................................57
24. Fuel Sub Level Sensor ..............................................................................58
25. Fuel Filter ..................................................................................................60
26. Fuel Cut Valve...........................................................................................61
27. Fuel Damper Valve ...................................................................................62
28. Fuel Delivery, Return and Evaporation Lines............................................63
29. Fuel System Trouble in General ...............................................................66

FU(H4SO)-5
FUEL INJECTION (FUEL SYSTEM)
General Description
2. AIR INTAKE SYSTEM
(1) Gasket (5) Throttle bodyTightening torque: N⋅m (kgf-m, ft-lb)
(2) Throttle position sensor (6) Intake air temperature sensorT1: 1.6 (0.16, 1.2)
(3) Idle air control solenoid valve (7) GrommetT2: 22 (2.2, 15.9)
(4) Manifold absolute pressure sensor (8) Air cleaner case
FU-00247
(2)
(3) (4)
(5) (1)
T1
T1
T1
T2
(8) (6)(7)

FU(H4SO)-13
FUEL INJECTION (FUEL SYSTEM)
Throttle Body
2. Throttle Body
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the air cleaner case. IN(H4SO)-6, REMOVAL, Air Cleaner Case.>
3) Disconnect the accelerator cable (A).
4) Disconnect the cruise control cable (B). (With
cruise control model)
5) Disconnect the connectors from idle air control
solenoid valve, throttle position sensor and mani-
fold absolute pressure sensor.
6) Disconnect the engine coolant hoses (A) from
the throttle body.7) Remove the bolts (B) which install throttle body
to the intake manifold.
B: INSTALLATION
1) Install in the reverse order of removal.
NOTE:
Replace the gasket with a new one.
Tightening torque:
THROTTLE BODY;
22 N
⋅m (2.2 kgf-m, 15.9 ft-lb)
2) Adjust the accelerator cable play. SP(H4SO)-7, ADJUSTMENT, Accelerator Pedal.>
(A) Throttle position sensor
(B) Manifold absolute pressure sensor
(C) Idle air control solenoid valve
FU-00009
FU-00251
(B)
(A)
FU-00378
(B)
(A)(C)
FU-00253
(B)
(B)
(A)(A)

FU(H4SO)-31
FUEL INJECTION (FUEL SYSTEM)
Manifold Absolute Pressure Sensor
9. Manifold Absolute Pressure
Sensor
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Disconnect the connector from the manifold ab-
solute pressure sensor.
3) Remove the manifold absolute pressure sensor.
B: INSTALLATION
Install in the reverse order of removal.
Tightening torque:
1.6 N
⋅m (0.16 kgf-m, 1.2 ft-lb)
NOTE:
Replace the O-ring with a new one.
FU-00009
FU-00294
FU-00295
FU-00295
FU-00296

EN(H4SO)-5
ENGINE (DIAGNOSTIC)
Check List for Interview
2. CHECK LIST No. 2
Check the following items about the vehicle’s state when malfunction indicator light turns on.
NOTE:
Use copies of this page for interviewing customers.
a) Other warning lights or indicators turn on. ❏ Yes / ❏ No
❏ Low fuel warning light
❏ Charge indicator light
❏ AT diagnostic indicator light
❏ ABS Warning light
❏ Oil pressure indicator light
b) Fuel level
 Lack of gasoline: ❏ Yes / ❏ No
 Indicator position of fuel gauge:
 Experienced running out of fuel: ❏ Ye s / ❏ No
c) Intentional connecting or disconnecting of harness connectors or spark plug cords: ❏ Yes / ❏ No
 What:
d) Intentional connecting or disconnecting of hoses: ❏ Ye s / ❏ No
 What:
e) Installing of other parts except genuine parts: ❏ Ye s / ❏ No
 What:
 Where:
f) Occurrence of noise: ❏ Yes / ❏ No
From where:
 What kind:
g) Occurrence of smell: ❏ Yes / ❏ No
From where:
 What kind:
h) Intrusion of water into engine compartment or passenger compartment: ❏ Yes / ❏ No
i) Troubles occurred
❏ Engine does not start.
❏ Engine stalls during idling.
❏ Engine stalls while driving.
❏ Engine speed decreases.
❏ Engine speed does not decrease.
❏ Rough idling
❏ Poor acceleration
❏ Back fire
❏ After fire
❏ Does not shift.
❏ Excessive shift shock

EN(H4SO)-7
ENGINE (DIAGNOSTIC)
General Description
 The antenna feeder must be placed as far
apart as possible from the ECM and MFI har-
ness.
 Carefully adjust the antenna for correct
matching.
 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.
13) 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.
14) Problems in the electronic-controlled automatic
transmission may be caused by failure of the en-
gine, the electronic control system, the transmis-
sion proper, or by a combination of these. These
three causes must be distinguished clearly when
performing diagnostics.
15) 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.
16) In AT models, do not continue the stall for more
than five seconds. (from closed throttle, fully open
throttle to stall engine speed.)
17) 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 grounding terminal is proper-
ly 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.
EN-00153

EN(H4SO)-11
ENGINE (DIAGNOSTIC)
Electrical Component Location
 SENSOR
EN-02379
(1)(2)
(3)(4)
(5)
(6) (7)(8)
(1) Intake air temperature sensor (4) Throttle position sensor (8) Engine coolant temperature sen-
sor (with AT warmer)
(2) Manifold absolute pressure sensor (5) Knock sensor
(3) Engine coolant temperature sen-
sor (without AT warmer)(6) Camshaft position sensor
(7) Crankshaft position sensor

EN(H4SO)-23
ENGINE (DIAGNOSTIC)
Engine Control Module (ECM) I/O Signal
Small light switch B137 20ON: 0
OFF: 10 — 13ON: 0
OFF: 12 — 14—
Blower fan switch B137 13ON: 0
OFF: 10 — 13ON: 0
OFF: 12 — 14—
Rear defogger switch B137 4ON: 0
OFF: 10 — 13ON: 0
OFF: 12 — 14—
Front oxygen (A/F) sen-
sor signal 1B136 13 — 2.05 — 2.25 —
Front oxygen (A/F) sen-
sor signal 2B136 22 — 1.75 — 1.95 —
Manifold absolute pres-
sure sensorB135 15 4.0 — 4.8 1.1 — 1.9 —
Intake air temperature
sensorB137 6 3.15 — 3.33 3.15 — 3.33Intake air temperature: 25°C
(75°F)
SSM/GST communica-
tion lineB137 16Less than 1←→
More than 4Less than 1←→
More than 4—
GND (sensor) B136 19 0 0 —
GND (injector) B134 35 0 0 —
GND (ignition system) B136 26 0 0 —
GND (power supply) B134 7 0 0 —
GND (control system)B137 14 0 0 —
B135 21 0 0 —
GND (oxygen sensor
heater 1)B136 5 0 0 —
GND (oxygen sensor
heater 2)B136 16 0 0 — DESCRIPTION Connector No. Terminal No.Signal (V)
NOTE
Ignition SW ON
(engine OFF)Engine ON
(Idling)

EN(H4SO)-27
ENGINE (DIAGNOSTIC)
OBD-II General Scan Tool
9. OBD-II General Scan Tool
A: OPERATION
1. HOW TO USE OBD-II GENERAL SCAN
TOOL
1) Prepare a general scan tool (OBD-II general
scan tool) required by SAE J1978.
2) Connect the OBD-II general scan tool to its data
link connector in the lower portion of the instrument
panel (on the driver’s side).3) Using the OBD-II general scan tool, call up the
DTC and freeze frame data.
OBD-II general scan tool functions consist of:
(1) MODE $01: Current powertrain diagnostic
data
(2) MODE $02: Powertrain freeze frame data
(3) MODE $03: Emission-related powertrain
DTC
(4) MODE $04: Clear/Reset emission-related
diagnostic information
Read out data according to repair procedures. (For
detailed operation procedures, refer to the OBD-II
General Scan Tool Operation Manual.)
NOTE:
For details concerning DTCs, refer to the List of Di-
agnostic Trouble Code (DTC). 72, List of Diagnostic Trouble Code (DTC).>
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).
ME-00325
PID Data Unit of measure
01 Number of emission-related powertrain DTC and malfunction indicator light status ON/OFF
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim%
07 Long term fuel trim%
0B Intake manifold absolute pressure kPa
0C Engine speedrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
10 Air flow rate of manifold absolute pressure sensor g/sec
11 Throttle valve opening angle%
13 Check whether oxygen sensor is installed. —
14Oxygen sensor output voltage and short term fuel trim — bank 1 associated with oxygen sen-
sorV and%
15Oxygen sensor output voltage and short term fuel trim — bank 2 associated with oxygen sen-
sorV and %
1C On-board diagnostic system—

EN(H4SO)-28
ENGINE (DIAGNOSTIC)
OBD-II General Scan Tool
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).
4. MODE $03 (EMISSION-RELATED POWERTRAIN DIAGNOSTIC TROUBLE CODES)
Refer to “Read Diagnostic Trouble Code (DTC)” for information about data denoting emission-related pow-
ertrain DTC.
5. MODE $04 (CLEAR/RESET EMISSION-RELATED DIAGNOSTIC INFORMATION)
Refers to the mode used to clear or reset emission-related diagnostic information (OBD-II trouble diagnostic
information).
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruction manual to clear or reset emission-related diag-
nostic information (MODE $04).
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 fuel trim%
0B Intake manifold absolute pressure kPa
0C Engine speedrpm
0D Vehicle speedkm/h