W8050GE  01 MY FORESTER New Car Features 73J欧州 Gr.

hyou_e

2001 Model Year

PDF Service Manual

NEW CAR INFORMATION SECTION

(W8050GE)
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. foreword

2001 FORESTER SERVICE MANUAL

QUICK REFERENCE INDEX

NEW CAR INFORMATION SECTION

Specifications SPC

FOREWORD Fuel Injection (Fuel System) FU (SOHC)

FU (SOHC
Fuel Injection (Fuel System) w/o OBD)

FU (DOHC
Fuel Injection (Fuel System)
TURBO)

Emission Control
EC (SOHC)
This manual has been prepared to provide information (Aux. Emission Control Devices)
for the construction, operation and other technical de-
tails of SUBARU vehicles. Emission Control EC (SOHC
Read this manual thoroughly and make the most of it (Aux. Emission Control Devices) w/o OBD)
to give better service to your customers and improve
your knowledge of vehicle maintenance. Emission Control EC (DOHC
(Aux. Emission Control Devices) TURBO)

Intake (Induction) IN (SOHC)

IN (DOHC
Intake (Induction)
TURBO)

Mechanical ME (SOHC)

ME (DOHC
Mechanical
TURBO)

Exhaust EX (SOHC)

EX (SOHC
Exhaust w/o OBD)

EX (DOHC
Exhaust
TURBO)

Cooling CO

Lubrication LU
All information, illustration and specifications con-
tained in this manual are based on the latest product Speed Control System SP
information available at the time of publication ap-
proval.
Ignition IG (SOHC)
FUJI HEAVY INDUSTRIES LTD.

W8050GE

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. foreword

FOREWORD
QUICK REFERENCE INDEX

IG (SOHC
Ignition w/o OBD)

IG (DOHC
Ignition
TURBO)

Starting/Charging SC

Control System CS

Automatic Transmission AT

Manual Transmission
MT
and Differential

Clutch CL

Front Suspension FS

Rear Suspension RS

Differentials DI

Drive Shaft System DS

ABS ABS

Brakes BR

Parking Brake PB

Power Assisted System

PS
(Power Steering)

HVAC System
AC
(Heater, Ventilator and A/C)

Airbag System AB

Seat Belt System SB

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. foreword

FOREWORD
QUICK REFERENCE INDEX

Wiper and Washer Systems WW

Glass/Windows/Mirrors GW

Body Structure BS

Instrumentation/Driver Info IDI

Seats SE

Security and Locks SL

Sunroof/T-top/Convertible Top SR

Exterior/Interior Trim EI

Exterior Body Panels EB

Cruise Control System CC

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. foreword

FOREWORD

All right reserved. This book may not be reproduced or

copied, in whole or in part, without the written permis-
sion of FUJI HEAVY INDUSTRIES LTD., TOKYO JA-
PAN

SUBARU, and are trademarks of FUJI

HEAVY INDUSTRIES LTD.

 Copyright 2000 FUJI HEAVY INDUSTRIES LTD.

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SPC_00

SPECIFICATIONS SPC SPC

Page
1. Forester ...............................................................................2

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FORESTER
Specifications

1. Forester
A: DIMENSIONS
Model 2.0 L Non-TURBO 2.0 L TURBO
Overall length mm (in) 4,460 (175.6), 4,530 (178.3)*1
Overall width mm (in) 1,735 (68.3), 1,765 (69.5)*2
Overall height (at CW) mm (in) 1,595 (62.8) 1,585 (62.4)
Compartment Length mm (in) 1,745 (68.7)
Width mm (in) 1,435 (56.5)
Height mm (in) 1,245 (49.0), 1,220 (48.0)*3
Wheelbase mm (in) 2,525 (99.4)
Tread Front mm (in) 1,475 (58.1)
Rear mm (in) 1,465 (57.7)
Minimum road clearance mm (in) 190 (7.5), 200 (7.9)*4
*1:With bush bar
*2:With fender flare
*3:With sunroof
*4:Australia spec. vehicles

B: ENGINE
Model 2.0 L Non-TURBO 2.0 L TURBO
Engine type Horizontally opposed, liquid cooled, 4-cylinder, 4-stroke gasoline engine
Valve arrangement Overhead camshaft type
Bore x Stroke mm (in) 92 x 75 (3.62 x 2.95)
Displacement cm3 (cu in) 1,994 (121.67)
Compression ratio 10.0 8.0
Firing order 1—3—2—4
Idle speed at Park/
rpm 700 ± 100
Neutral position
Maximum output kW (HP)/rpm 101 (137)/5,600 130 (174)/5,600
Maximum torque N.m (kgf-m, ft-lb)/rpm 186 (19.0, 137.0)/3,600 245 (25, 181)/3,200

C: ELECTRICAL
Model 2.0 L Non-TURBO 2.0 L TURBO
Ignition timing at idling speed BTDC/rpm 12° ± 10°/700
Spark plug Type and manufacturer NGK: BK5E-11 (without catalyst) NGK: PFR6B
CHAMPION: RC10YC4 (with catalyst)
Generator 12V — 75A
Battery Type and For Europe 5MT: 12V — 48AH
capacity (5HR) 4AT: 12V — 52AH
For Australia 12V — 40AH
Others 12V — 40AH

SPC-2

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FORESTER
Specifications

D: TRANSMISSION
Model 2.0 L Non-TURBO 2.0 L TURBO
AWD
Transmission type 5MT*1 4AT*2 5MT*3 4AT*2
Clutch type DSPD TCC DSPD TCC
Gear ratio 1st 3.454 2.785 3.454 2.785
2nd 2.062 1.545 1.947 1.545
3rd 1.448 1.000 1.366 1.000
4th 1.088 0.694 0.972 0.694
5th 0.871 — 0.738 —
Reverse 3.333 2.272 3.333 2.272
Auxiliary transmission gear High 1.000 — — —
ratio
Low 1.447 — — —
Reduction 1st reduction Type of gear — Helical — Helical
gear (Front
Gear ratio — 1.000 — 1.000
drive)
Final Type of gear Hypoid Hypoid Hypoid Hypoid
reduction
Gear ratio 4.111 4.444 4.444 4.111
Reduction Transfer Type of gear Hypoid — Hypoid —
gear (Rear reduction
Gear ratio 1.000 — 1.081*4, 1.000*5 —
drive)
Final Type of gear Hypoid Hypoid Hypoid Hypoid
reduction
Gear ratio 4.111 4.444 4.111*4, 4.444*5 4.111
5MT*1:5 x 2 forward speeds with synchromesh and 1-reverse — with center differential and viscous coupling
4AT*2:Electronically controlled fully-automatic, 4-forward speeds and 1-reverse — with hydraulically controlled transfer clutch
5MT*3:5-forward speeds with synchromesh and 1-reverse — with center differential and viscous coupling
DSPD:Dry Single Plate Diaphragm
TCC:Torque Converter Clutch
*4:For Europe
*5:Others

E: STEERING
Model LHD RHD
Type Rack and Pinion
Turns, lock to lock 3.4 3.0
Minimum turning circle m (ft) Curb to curb: 10.8 (35.4)

F: SUSPENSION
Front MacPherson strut type, Independent, Coil spring
Rear Dual link strut type, Independent, Coil spring

G: BRAKE
Model Australia spec. vehicles and 2000 Others
TURBO
Service brake system Dual circuit hydraulic with vacuum suspended power unit
Front Ventilated disc brake
Rear Disc brake Drum brake
Parking brake Mechanical on rear brakes

SPC-3

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FORESTER
Specifications

H: TIRE
Rim size 15 x 6J 16 x 6 1/2 JJ
Tire size 205/70R15 215/60R16
Type Steel belted radial, Tubeless

I: CAPACITY
Model 2.0 L Non-TURBO 2.0 L TURBO
AWD AWD
5MT 4AT 5MT 4AT
Fuel tank ȏ (US gal, Imp gal) 60 (15.9, 13.2) 60 (15.9, 13.2)
Engine oil Upper level ȏ (US qt, Imp qt) 4.5 (4.8, 4.0) 5.0 (5.3, 4.4)
Lower level ȏ (US qt, Imp qt) 3.5 (3.7, 3.1) 4.0 (4.2, 3.5)
Transmission gear oil ȏ (US qt, Imp qt) 4.0 (4.2, 3.5) — 3.5 (3.7, 3.1) —
Automatic transmission fluid ȏ (US qt, Imp qt) — 8.4 (8.9, 7.4) — 9.3 (9.8, 8.2)
AT differential gear oil ȏ (US qt, Imp qt) — 1.2 (1.3, 1.1) — 1.2 (1.3, 1.1)
AWD rear differential gear oil ȏ (US qt, Imp qt) 0.8 (0.8, 0.6) 0.8 (0.8, 0.6)
Power steering fluid ȏ (US qt, Imp qt) 0.7 (0.7, 0.6) 0.7 (0.7, 0.6)
Engine coolant ȏ (US qt, Imp qt) 6.4 (6.8, 5.6) 6.3 (6.7, 5.5) 6.4 (6.8, 5.6) 6.3 (6.7, 5.5)

SPC-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SPC_01

FORESTER
Specifications

J: WEIGHT
1. EXCEPT AUSTRALIA SPEC. VEHICLE
Model 2.0 L Non-TURBO
AWD
LHD RHD
5MT 4AT 5MT 4AT
Curb weight (C.W.) Front kg (lb) 730 (1,610) 745 (1,643) 745 (1,643) 760 (1,676)
Rear kg (lb) 615 (1,356) 615 (1,356) 620 (1,367) 620 (1,367)
Total kg (lb) 1,345 (2,966) 1,360 (2,999) 1,365 (3,010) 1,380 (3,043)
Maximum permissible Front kg (lb) 920 (2,029) 930 (2,051) 920 (2,029) 930 (2,051)
axle weight (M.P.A.W.)
(M P A W )
Rear kg (lb) 990 (2,183) 990 (2,183) 990 (2,183) 990 (2,183)
Maximum permissible Total kg (lb) 1,875(4,134) 1,890 (4,163) 1,875 (4,134) 1,890 (4,167)
weight (M.P.W.)

Model 2.0 L TURBO

AWD
LHD RHD
5MT 4AT 5MT 4AT
Curb weight (C.W.) Front kg (lb) 795 (1,753) 815 (1,797) 790 (1,742) 810 (1,786)
Rear kg (lb) 635 (1,400) 630 (1,389) 630 (1,389) 630 (1,389)
Total kg (lb) 1,430 (3,153) 1,445 (3,186) 1,420 (3,131) 1,440 (3,185)
Maximum permissible Front kg (lb) 975 (2,150) 995 (2,195) 975 (2,150) 975 (2,150)
axle weight (M.P.A.W.)
(M P A W )
Rear kg (lb) 1,010 (2,225) 1,010 (2,225) 1,010 (2,225) 1,010 (2,225)
Maximum permissible Total kg (lb) 1,950 (4,300) 1,970 (4,344) 1,950 (4,300) 1,970 (4,344)
weight (M.P.W.)

NOTE:
When any of the following optional parts are installed, add the weight to the curb weight.
Weight of ABS ABS Cruise Self- Fog Air con- Sunroof SRS SRS Cold Cold
optional parts (Turbo (Non- control levelizer lamp ditioner airbag airbag weath- weather
model) Turbo (Driver (Side) er pack pack
model) & pas- (Leather
senger seat)
Front kg (lb) 10 11 2 –1 3.6 17 9 3 2 2 2.6
(22) (24) (4) (–2) (7.9) (38) (20) (7) (4.4) (4) (5.7)
Rear kg (lb) –1 –1 0 2 –1 –3 14 2 2 –1 4.4
(–2) (–2) (0) (4) (–2) (–7) (31) (4) (4.4) (–2) (9.7)
Total kg (lb) 9 10 2 1 2.6 14 23 5 4 1 7.0
(20) (22) (4) (2) (5.7) (31) (51) (11) (8.8) (2) (15.4)

SPC-5

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SPC_01

FORESTER
Specifications

2. AUSTRALIA SPEC. VEHICLE

Model 2.0 L Non-TURBO 2.0 L TURBO
AWD AWD
RHD RHD
5MT 4AT 5MT 4AT
Unladen mass (U.M.) Front kg (lb) 740 (1,632) 755 (1,665) 810 (1,786) 835 (1,841)
Rear kg (lb) 625 (1,378) 625 (1,378) 630 (1,389) 625 (1,378)
Total kg (lb) 1,365 (3,010) 1,380 (3,043) 1,440 (3,175) 1,460 (3,219)
Gross vehicle mass Front kg (lb) 885 (1,951) 910 (2,007) 960 (2,117) 980 (2,161)
(G V M )
(G.V.M.)
Rear kg (lb) 990 (2,183) 980 (2,161) 990 (2,183) 990 (2,183)
Total kg (lb) 1,875 (4,134) 1,890 (4,167) 1,950 (4,300) 1,970 (4,344)

NOTE:
When any of the following optional parts are installed, add the weight to the unladen mass.
Weight of ABS Cruise Self- Fog lamp Air condi- Sunroof SRS air- SRS air- Cold
optional parts control levelizer tioner bag bag weather
(Driver & (Side) pack
passen-
ger
Front kg (lb) 10 (22) 2 (4) –1 (–2) 3.6 (7.9) 17 (38) 9 (20) 3 (7) 2 (4.4) 2.6 (5.7)
Rear kg (lb) –1 (–2) 0 (0) 2 (4) –1 (–2) –3 (–7) 14 (31) 2 (4) 2 (4.4) 4.4 (9.7)
Total kg (lb) 9 (20) 2 (4) 1 (2) 2.6 (5.7) 14 (31) 23 (51) 5 (11) 4 (8.8) 7.0 (15.4)

SPC-6

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S00

FUEL INJECTION
(FUEL SYSTEM) FU (SOHC)
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 FU
SOHC
2. Air Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Fuel Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Sensors and Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5. Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6. On-board Diagnosis System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S01

GENERAL
Fuel Injection (Fuel System)

1. General
D The Multipoint Fuel Injection (MFI) system supplies optimum air-fuel mixture under every engine
operating condition through the use of the latest electronic control technology.
This system pressurizes the fuel to a constant pressure and injects it into each intake air port in
the cylinder head. The injection quantity of fuel is controlled by an intermittent injection system
where an electro-magnetic injection valve or injector opens for a short period that is precisely con-
trolled depending on the quantity of air appropriate for each condition of operation. In actual con-
trol, an optimum fuel injection quantity is achieved by varying the duration of an electric pulse ap-
plied to the injector. This way of control enables simple, yet highly precise metering of the fuel.
D The engine control module (ECM) that controls the fuel injection system corrects the fuel injec-
tion amount depending on the vehicle speed, throttle opening, coolant temperature and other ve-
hicle-operation-related information. The ECM receives the information in the form of electric sig-
nals from the corresponding sensors and switches.
The MFI system also has the following features:
D Reduced exhaust emissions
D Reduced fuel consumption
D Increased engine output
D Quick response to accelerator and brake pedal operation
D Superior startability and warm-up performance in cold weather due to corrective controls made
according to coolant and intake air temperatures

FU-2

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AIR LINE
Fuel Injection (Fuel System)

2. Air Line
A: GENERAL
The air filtered by the air cleaner enters the throttle body where it is regulated in the volume by the
throttle valve and then enters the intake manifold. It is then distributed to each cylinder where the
air is mixed with fuel injected by the injector. During idling operation, air flows into the cylinder
through the idle air control solenoid valve, bypassing the throttle valve. This enables controlling
the engine idling speed properly.

B: INTAKE MANIFOLD PRESSURE AND AIR TEMPERATURE SENSORS

The intake manifold pressure sensor and the intake air temperature sensor are integrated into a
single unit. The unit is mounted on the intake manifold and measures the absolute air pressure in
the intake manifold as well as the temperature of the intake air.
The measured pressure and temperature are converted into electrical signals and sent to the
ECM. The ECM uses these signals to control injection and ignition timing as well as the fuel injec-
tion amount.

H2H2825B

(1) Pressure sensor

(2) Intake air temperature sensor

FU-3

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AIR LINE
Fuel Injection (Fuel System)

C: ATMOSPHERIC PRESSURE SENSOR

The atmospheric pressure sensor converts pressure values into electric signals, and sends the
signals to the ECM.

NF0007

(1) Sensor unit (6) Terminal

(2) O-ring (7) Inner lead
(3) Case (8) Resin
(4) Pipe (9) Metal lid
(5) Through capacity

D: THROTTLE BODY
D In response to operation of the accelerator pedal, the throttle valve in the throttle body opens/
closes to regulate the volume of the air drawn into the combustion chamber.
D During idling, the throttle valve is almost fully closed and the volume of air passing through the
throttle body is less than that passing through the idle air control solenoid valve.
D More than half of the air necessary for idling is supplied to the intake manifold via the idle air
control solenoid valve which controls properly the engine idling speed, so the idling speed needs
not be adjusted.

FU-4

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AIR LINE
Fuel Injection (Fuel System)

E: THROTTLE POSITION SENSOR

D The throttle position sensor is mounted in the throttle body and linked to the throttle valve.
D The throttle position sensor sends the ECM voltage signal corresponding to the opening of the
throttle valve. When the sensor’s output voltage exceeds a predetermined level, the ECM inter-
prets it as complete closure of the throttle valve. When the output voltage is at another predeter-
mined level, the ECM recognizes that the throttle valve is at a wide open position. Since the output
characteristics of the sensor change over years, the ECM is provided with a learning function to
be able to interpret signals into throttle valve angles always correctly.

B2H2004B

(1) Lever
(2) Terminal

FU-5

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S02

AIR LINE
Fuel Injection (Fuel System)

F: IDLE AIR CONTROL SOLENOID VALVE

D The idle air control solenoid valve is located in the throttle body and regulates the amount of in-
take air that flows bypassing the throttle valve into the intake manifold during engine idling. It is
activated by a signal from the ECM in order to maintain the engine idling speed at a target speed.
D The idle air control solenoid valve is a stepping motor type solenoid-actuated valve which con-
sists of coils, a shaft, a permanent magnet, a spring and a housing. The housing is an integral part
of the throttle body.
D The stepping motor consists of two paired coils, the coils of each pair being arranged face to
face with a shaft in between.
D The shaft has a screw at the end around which the permanent magnets are arranged.
D As current flows in the form of pulses through the paired coils sequentially while alternating the
polarity, the N and S poles of the permanent magnets around the shaft are repelled by the same
poles of the magnetism generated by the coils. This causes a nut externally fixed to the magnets
and internally engaging with the screw of the shaft to turn.
The shaft then goes upward or downward.
D This upward and downward motions of the shaft open or close the valve port, adjusting the
amount of bypass air.

B2H2005B

(1) Connector
(2) Permanent magnet
(3) Shaft
(4) Coil
(5) Spring

FU-6

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AIR LINE
Fuel Injection (Fuel System)

G: AIR ASSIST INJECTOR SOLENOID VALVE

The air assist injector solenoid valve is located in the piping between the throttle body and the in-
jector and secured to the intake manifold.
This solenoid valve is opened or closed by the signals from the ECM, adjusting the flow rate of air
supplied to the injector.

B2H3447B

(1) Sheet A: From idle air control solenoid valve

(2) Solenoid B: To injector
(3) Plunger and valve
(4) Spring
(5) Connector

FU-7

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FUEL LINE
Fuel Injection (Fuel System)

3. Fuel Line
A: GENERAL
D The fuel pressurized by the fuel tank inside pump is delivered to each fuel injector by way of the
fuel pipe and fuel filter. Fuel injection pressure is regulated to an optimum level by the pressure
regulator.
D Each injector injects fuel into the intake port of the corresponding cylinder where the fuel is
mixed with air. The mixture then enters the cylinder.
Fuel injection amount and timing are regulated by the ECM.

S2H2174A

(1) Purge control solenoid valve (10) Air vent pipe

(2) Pressure regulator (11) Fuel filter
(3) Fuel injector (12) Fuel pump
(4) Throttle body (13) Fuel cut valve
(5) Intake manifold (14) Jet pump
(6) Two-way valve (15) Fuel return line
(7) Canister (16) Fuel delivery line
(8) Filler cap (17) Fuel evaporation line
(9) Filler pipe (18) Fuel tank

FU-8

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FUEL LINE
Fuel Injection (Fuel System)

B: PRESSURE REGULATOR
The pressure regulator is installed at the injector end of the fuel supply line. It has a fuel chamber
and spring chamber separated by a diaphragm. Fuel chamber is connected to the fuel supply
line and the spring chamber is connected to the intake manifold. Fuel chamber also has a relief
valve connected to the fuel return line through which fuel returns to the fuel tank. When the intake
manifold vacuum increases, the diaphragm is pulled and the relief valve opens to decrease the
fuel supply line pressure (or fuel injection pressure). When the intake manifold vacuum decreases,
the diaphragm is pushed by the spring to increase the fuel supply line pressure. Thus, the differ-
ence between the fuel injection pressure and the intake manifold vacuum is kept at a constant level
of 299.1 kPa (3.05 kgf/cm2, 43.4 psi) to precisely control the amount of injected fuel.

S2H0623C

(1) Relief valve A: To intake manifold

(2) Diaphragm B: Fuel IN
C: Fuel OUT

FU-9

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FUEL LINE
Fuel Injection (Fuel System)

C: FUEL INJECTORS
D The MFI system employs top feed type fuel injectors with an air assist feature.
D Each injector is installed in the fuel pipe in such a way that the injector is cooled by fuel.
D The features of this type of fuel injector are as follows:
1) High heat resistance
2) Low driving noise
3) Easy to service
4) Small size
D The injector injects fuel according to the valve open signal from the ECM. The needle valve is
lifted by the solenoid which is energized on arrival of the valve open signal.
D Since the injector’s nozzle hole area, the lift of valve and the fuel pressure are kept constant, the
amount of fuel injected is controlled only by varying the duration of the valve open signal from the
ECM.
D Fuel atomization is enhanced using assist air supplied from the idle air control solenoid valve
passing through the passage formed in the intake manifold at the area in which each injector is
installed. This contributes not only to higher combustion efficiency and higher output but also to
cleaner exhaust emissions.

B2H3442C

(1) Filter (4) Seal

(2) O-ring (5) Connector
(3) Plunger

FU-10

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FUEL LINE
Fuel Injection (Fuel System)

D: FUEL TANK
The fuel tank utilizes a two-compartment design to ensure sufficient capacity without interfering
with the rear differential. It is provided with a suction jet pump (included in the fuel pump and fuel
level sensor assembly) which transfers fuel from one compartment to the other. Each compartment
has an individual fuel level sensor.
The fuel tank is located under the rear seat and secured with hold-down bands.

NF0325

(1) Fuel pump and fuel level sensor assembly (4) Cushion
(2) Fuel sub level sensor (5) Steel
(3) Band

FU-11

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FUEL LINE
Fuel Injection (Fuel System)

E: FUEL PUMP AND FUEL LEVEL SENSOR ASSEMBLY

1. FUEL PUMP
The fuel pump consists of a motor, impeller, pump casing, pump cover, check valve and filter. It
is located in the fuel tank and combined with the fuel level sensor into a single unit. The operation
of this impeller type pump is very quiet.

S2H1957B

(1) Fuel pump A: From engine (return line)

(2) Fuel level sensor B: From sub tank
(3) Jet pump C: To engine (delivery line)
(4) Mesh filter D: Suction
(5) Impeller E: Discharge
(6) Check valve
(7) Pump casing
(8) Motor armature
(9) Vane groove

D When the ignition switch is turned ON, fuel pump relay is activated. Then the motor operates
to rotate the impeller.
D As the impeller rotates, fuel in a vane groove of the impeller flows along the fuel passage into
the next vane groove by centrifugal force. When fuel flows from one groove to the next, a pressure
difference occurs due to friction. This creates a pumping effect.
D The fuel pushed up by rotation of the impeller then passes through the clearance between the
armature and the magnet of the motor and is discharged through the check valve.
D When the fuel discharge pressure reaches the specified level, the relief valve opens and excess
fuel is released into the fuel tank. In this manner, the relief valve prevents an abnormal increase
in fuel pressure.
D When the engine and the fuel pump stop, spring force acts on the check valve to close the dis-
charge port, so that the fuel pressure in the fuel delivery line is retained.

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FUEL LINE
Fuel Injection (Fuel System)

2. FUEL LEVEL SENSOR

The fuel level sensor forms part of the fuel pump and located in the fuel tank. The sensor outputs
an electric resistance signal that varies with movement of its float to indicate the level of the fuel
remaining in the tank.

S2H2178A

(1) Fuel level sensor

(2) Float

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S03

FUEL LINE
Fuel Injection (Fuel System)

3. JET PUMP
D The jet pump utilizes the velocity of fuel returning from the engine to produce negative pressure
in it.
D Using the pumping effect produced by the negative pressure, the jet pump transfers fuel from
the sub-compartment to the main compartment of the fuel tank.
D When the return line nozzle is clogged, the fuel sent back through the return line flows back into
the fuel tank via the relief valve.

NF0328

(1) Relief valve A: Return line

(2) Nozzle

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FUEL LINE
Fuel Injection (Fuel System)

F: SUB-COMPARTMENT FUEL LEVEL SENSOR

This sensor detects the level of the fuel in the sub-compartment (the compartment in which the
fuel pump is not located) and acts as part of the fuel transfer line when the jet pump is in operation
to maintain the fuel in both compartments at the same level.

NF0396

(1) Fuel level sensor A: To jet pump

(2) Float

G: FUEL FILTER
The fuel filter located in the engine compartment is a pressure-withstanding, cartridge type. It has
a filter element in a metal case. The fuel entering the filter flows from the perimeter of the element
to the center of the filter and goes out from there.

NF0018

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

4. Sensors and Switches

A: FRONT OXYGEN (A/F) SENSOR
D The front oxygen sensor uses zirconium oxide (ZrO2) which is a solid electrolyte, at portions ex-
posed to exhaust gas.
D The zirconium oxide has the property of generating electromotive force when its both sides are
exposed to oxygen ions of different concentration and the magnitude of this electromotive force
depends on how much the difference is.
D The front oxygen sensor detects the amount of oxygen in exhaust gases by making use of this
property of the zirconium oxide material.
D The zirconium oxide material is formed into a closed end tube and its external surface is ex-
posed to exhaust gases with smaller oxygen ion concentration, whereas its internal surface is ex-
posed to atmospheric air. The external surface has a porous platinum coating. The sensor housing
is grounded to the exhaust pipe and the inside is connected to the ECM through the harness to
be able to use the current output from the sensor.
D The sensor incorporates a ceramic heater to improve its performance at low temperatures.

B2H4145B

(1) Sensor element (3) Protection tube

(2) Sensor housing (4) Gasket

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D When rich air-fuel mixture is burnt in the cylinder, the oxygen in the exhaust gases is almost com-
pletely used in the catalytic reaction by the platinum coating on the external surface of the zirconia
tube. This results in a very large difference in the oxygen ion concentration between the inside and
outside of the tube, and the electromotive force generated is large.
D When a lean air-fuel mixture is burnt in the cylinder, relatively large amount of oxygen remains
in the exhaust gases even after the catalytic action, and this results in a small difference in the oxy-
gen ion concentration between the tube’s internal and external surfaces. The electromotive force
in this case is very small.
D The difference in oxygen concentration changes drastically in the vicinity of the stoichiometric
air-fuel ratio, and hence the change in the electromotive force is also large. By using this informa-
tion, the ECM can determine the air-fuel ratio of the supplied mixture easily. The front oxygen sen-
sor does not generate much electromotive force when the temperature is low. The output charac-
teristics of the sensor stabilize at a temperature of approximately 700°C (1,292°F).

NF0331

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

B: REAR OXYGEN SENSOR

D The rear oxygen sensor is used to sense oxygen concentration in the exhaust gas. If the air-fuel
ratio is leaner than the stoichiometric ratio in the mixture (i.e., excessive amount of air), the exhaust
gas contains more oxygen. To the contrary, if the fuel ratio is richer than the stoichiometric ratio,
the exhaust gas contains almost no oxygen.
D Detecting the oxygen concentration in exhaust gas using the oxygen sensor makes it possible
to determine whether the air-fuel ratio is leaner or richer than the stoichiometry.
D The rear oxygen sensor has a zirconia tube (ceramic) which generates voltage if there is a differ-
ence in oxygen ion concentration between the inside and outside of the tube. Platinum is coated
on the inside and outside of the zirconia tube as a catalysis and electrode material. The sensor
housing is grounded to the exhaust pipe and the inside is connected to the ECM through the har-
ness.
D A ceramic heater is employed to improve performance at low temperatures.

B2H3810C

(1) Protection tube (4) Gasket

(2) Ceramic heater (5) Sensor housing
(3) Zirconia tube (6) Harness

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D When rich air-fuel mixture is burnt in the cylinder, the oxygen in the exhaust gases is almost com-
pletely used in the catalytic reaction by the platinum coating on the external surface of the zirconia
tube. This results in a very large difference in the oxygen ion concentration between the inside and
outside of the tube, and the electromotive force generated is large.
D When a lean air-fuel mixture is burnt in the cylinder, relatively large amount of oxygen remains
in the exhaust gases even after the catalytic action, and this results in a small difference in the oxy-
gen ion concentration between the tube’s internal and external surfaces. The electromotive force
in this case is very small.
D The difference in oxygen concentration changes drastically in the vicinity of the stoichiometric
air-fuel ratio, and hence the change in the electromotive force is also large. By using this informa-
tion, the ECM can determine the air-fuel ratio of the supplied mixture easily. The rear oxygen sensor
does not generate much electromotive force when the temperature is low. The output characteris-
tics of the sensor stabilize at a temperature of approximately 300 to 400°C (572 to 752°F).

NF0333

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

C: ENGINE COOLANT TEMPERATURE SENSOR

The engine coolant temperature sensor is located on the engine coolant pipe. The sensor uses
a thermistor whose resistance changes inversely with temperature. Resistance signals as engine
coolant temperature information are transmitted to the ECM to make fuel injection, ignition timing,
purge control solenoid valve and other controls.

S2H1113B

(1) Connector (2) Thermistor element

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S04

SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D: CRANKSHAFT POSITION SENSOR

D The crankshaft position sensor is installed on the oil pump which is located in the front center
portion of the cylinder block. The sensor generates a pulse when one of the teeth on the perimeter
of the crankshaft sprocket (rotating together with the crankshaft) passes in front of it. The ECM de-
termines the crankshaft angular position by counting the number of pulses.
D The crankshaft position sensor is a molded type which consists of a magnet, core, coil, terminals
and other components as illustrated below.

NF0024

(1) Terminal (4) Coil

(2) Yoke core (5) Core
(3) Magnet (6) Cover

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D As the crankshaft rotates, each tooth aligns with the crankshaft position sensor. At that time, the
magnetic flux in the sensor’s coil changes since the air gap between the sensor pickup and the
sprocket changes. This change in magnetic flux induces a voltage pulse in the sensor and the
pulse is transmitted to the ECM.

NF0398

(1) Crankshaft position sensor (3) Crankshaft half rotation

(2) Crankshaft sprocket

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S04

SENSORS AND SWITCHES

Fuel Injection (Fuel System)

E: CAMSHAFT POSITION SENSOR

D The camshaft position sensor is located on the left-hand camshaft support. It detects the com-
bustion cylinder at any given moment.
D The sensor generates a pulse when one of the bosses on the back of the left-hand camshaft
drive sprocket passes in front of the sensor. The ECM determines the camshaft angular position
by counting the number of pulses.
Internal construction and the basic operating principle of the camshaft position sensor are similar
to those of the crankshaft position sensor. A total of seven bosses are arranged at equally spaced
four locations (one each at two locations, two at one location, and three at one location) of the
sprocket as shown below.

B2H3812C

(1) Boss A: Camshaft one rotation (Crankshaft two rotations)

(2) Camshaft sprocket B: Cylinder identification signal
(3) Air gap
(4) Camshaft position sensor

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

F: KNOCK SENSOR
D The knock sensor is installed on the cylinder block, and senses knocking that occurs in the en-
gine.
D The sensor is a piezo-electric type which converts vibration resulting from knocking into electric
signals.
D In addition to a piezo-electric element, the sensor has a weight and case as its components.
If knocking occurs in the engine, the weight in the case moves causing the piezo-electric element
to generate a voltage.
D The knock sensor harness is connected to the bulkhead harness.

B2H1998B

(1) Nut A: To knock sensor harness

(2) Weight
(3) Resistor
(4) Housing
(5) Piezo-electric element

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

G: VEHICLE SPEED SENSOR

1. MT VEHICLES
D The vehicle speed sensor is mounted on the transmission.
D The vehicle speed sensor generates a 4-pulse signal for every rotation of the front differential
and send it to the ECM and the combination meter.

B2H2458C

(1) Combination meter

(2) ECM
(3) Vehicle speed sensor
(4) Transmission

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

2. AT VEHICLES
D The vehicle speed sensor is mounted on the transmission.
D The vehicle speed sensor generates a 16-pulse signal for every rotation of the front differential
and send it to the transmission control module (TCM). The signal sent to the TCM is converted
there into a 4-pulse signal, and then sent to the ECM and the combination meter.

B2H2459B

(1) Combination meter

(2) ECM
(3) TCM
(4) Vehicle speed sensor
(5) Transmission

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S05

CONTROL SYSTEM
Fuel Injection (Fuel System)

5. Control System
A: GENERAL
The ECM receives signals from various sensors, switches, and other control modules. Using these
signals, it determines the engine operating conditions and if necessary, emits signals to one or
more systems to control them for optimum operation.
Major control items of the ECM are as follow:
D Fuel injection control
D Ignition system control
D Idle air control
D Fuel pump control
D Canister purge control*1
D Radiator fan control*2
D On-board diagnosis function

*1: Canister purge control is described under “EC (SOHC) – Emission Control (Aux. Emission Con-
trol Devices) Evaporative Emission Control System”.
*2: Radiator fan control is described under “CO – Cooling”.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

B: INPUT AND OUTPUT SIGNALS

Signal Unit Function
Intake air temperature and pressure Detects the temperature of intake and amount of intake air (Mea-
sensor sures the absolute pressure).
Detects the amount of intake air (Measure the atmospheric pres-
Atmospheric pressure sensor
sure).
Throttle position sensor Detects the throttle valve position.
Detects the density of oxygen in exhaust gases at the upstream of
Front oxygen (A/F) sensor
the front catalytic converter.
Detects the density of oxygen in exhaust gases at the downstream
Rear oxygen sensor
of the front catalytic converter.
Crankshaft position sensor Detects the crankshaft angular position.
Camshaft position sensor Detects the combustion cylinder.
Engine coolant temperature sensor Detects the engine coolant temperature.
Knock sensor Detects engine knocking.
Vehicle speed sensor Detects the vehicle speed.
Input signals
Ignition switch Detects operation of the ignition switch.
Starter switch Detects the condition of engine cranking.
Neutral position switch (MT) Detects that the gear is in neutral.
Park/Neutral position switch (AT) Detects shift positions.
Torque control signal Controls engine torque.
Heater circuit of front and rear oxy- Detects abnormality in the heater circuit of the front and rear oxygen
gen sensor sensors.
Fuel level sensor Detects the level of the fuel in fuel tank.
Diagnostics of TCM Detects the self-diagnostics of the TCM.
A/C switch Detects ON-OFF operation of the A/C switch.
Small light switch Detects ON-OFF operation of the small light switch.
Blower fan switch Detects ON-OFF operation of the blower fan switch.
Rear defogger switch Detects ON-OFF operation of the rear defogger switch.
Fuel Injector Activates an injector.
Ignition signal Turns the primary ignition current ON or OFF.
Fuel pump relay Turns the fuel pump relay ON or OFF.
A/C control relay Turns the A/C control relay ON or OFF.
Radiator fan control relay Turns the radiator fan control relay ON or OFF.
Output signals
Adjusts the amount of air flowing through the bypass line in the
Idle air control solenoid valve
throttle body.
Malfunction indicator lamp Indicates existence of abnormality.
Purge control solenoid valve Controls purge of evaporative gas absorbed by the canister.
Power supply Control ON/OFF of the main power supply relay.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

C: FUEL INJECTION CONTROL

D The ECM receives signals from various sensors and based on them, it determines the amount
of fuel injected and the fuel injection timing. It performs the sequential fuel injection control over
the entire engine operating range except during start-up of the engine.
D The amount of fuel injected depends upon the length of time the injector stays open. The fuel
injection duration is determined according to varying operating condition of the engine. For the
purpose of achieving highly responsive and accurate fuel injection duration control, the ECM per-
forms a new feedback control that incorporates a learning feature as detailed later.
D The sequential fuel injection control is performed such that fuel is injected accurately at the time
when the maximum air intake efficiency can be achieved for each cylinder (i.e., fuel injection is
completed just before the intake valve begins to open).

1. FUEL INJECTION DURATION

Fuel injection duration is basically determined as indicated below:
D During engine start-up:
The duration defined below is used.
D Duration of fuel injection during engine start-up ..... Determined according to the engine cool-
ant temperature detected by the engine coolant temperature sensor.
D During normal operation:
The duration is determined as follows:
Basic duration of fuel injection x Correction factors + Voltage correction time
D Basic duration of fuel injection ..... The basic length of time fuel is injected. This is determined
by two factors – the amount of intake air detected by the manifold pressure sensor and the en-
gine speed monitored by the crankshaft position sensor.
D Correction factors ..... See the next section.
D Voltage correction time ..... This is added to compensate for the time lag before operation of
injector that results from variation in the battery voltage.

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S05

CONTROL SYSTEM
Fuel Injection (Fuel System)

2. CORRECTION FACTORS
The following factors are used to correct the basic duration of fuel injection in order to make the
air-fuel ratio meet the requirements of varying engine operating conditions:
D Air-fuel ratio feedback factor:
This factor is used to correct the basic duration of fuel injection in relation to the actual engine
speed. (See the next section for more detail.)
D Start increment factor:
This factor is used to increase the fuel injection duration only while the engine is being cranked
to improve its startability.
D Coolant-temperature-dependent increment factor:
This factor is used to increase the fuel injection duration depending on engine coolant temperature
signals to facilitate cold starting. The lower the coolant temperature, the greater the increment.
D After-start increment factor:
D This factor is used to increase the fuel injection duration for a certain period immediately after
start of the engine to stabilize engine operation.
D The increment depends on the coolant temperature at the start of the engine.
D Wide-open-throttle increment factor:
This factor is used to increase the fuel injection duration depending on the relationship between
the throttle position sensor signal and manifold pressure sensor signal.
D Acceleration increment factor:
This factor is used to increase the fuel injection duration to compensate for a time lag between air
flow measurement and fuel injection control for better engine response to driver’s pedal operation
during acceleration.

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S05

CONTROL SYSTEM
Fuel Injection (Fuel System)

3. AIR-FUEL RATIO FEEDBACK FACTOR

The ECM creates this factor utilizing the front oxygen sensor signal. When the signal voltage is low,
the air-fuel ratio is richer than the stoichiometric ratio. The ECM then makes the fuel injection dura-
tion shorter by modifying the factor. When the voltage is high showing that the mixture is lean, the
ECM modifies the factor to make the injection duration longer. In this way, the air-fuel ratio is main-
tained at a level close to the stoichiometric ratio at which the three-way catalyst acts most effective-
ly.

NF0030

(1) Front catalyst (4) Fuel injector

(2) Exhaust gas (5) Combustion chamber
(3) Front oxygen (A/F) sensor

4. LEARNING FEATURE
The air-fuel ratio feedback control includes a learning feature which contributes to more accurate
and responsive control.
D In the air-fuel ratio feedback control, the ECM calculates the necessary amount of correction
based on data from the oxygen sensor and adds the result to the basic duration (which is stored
in the ECM’s memory for each condition defined by the engine speed and various loads.)
D Without a learning feature, the ECM carries out the above-mentioned process every time. This
means that if the amount of necessary correction is large, the air-fuel ratio feedback control be-
comes less responsive and less accurate.
D The learning feature enables the ECM to store the amount of correction into memory and add
it to the basic fuel injection duration to create a new reference fuel injection duration. Using the
reference duration as the basic duration for the injection a few times later, the ECM can reduce
the amount of correction and thus make its feedback control more accurate and responsive to
changes in the air-fuel ratio due to difference in driving condition and sensor/actuator characteris-
tics that may result from unit-to-unit variation or aging over time.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

D: IGNITION SYSTEM CONTROL

D The ECM determines operating condition of the engine based on signals from the pressure sen-
sor, engine coolant temperature sensor, intake air temperature sensor, crankshaft position sensor
and other sources. It then selects the ignition timing most appropriate for the condition thus deter-
mined from those stored in its memory and outputs at that timing a primary current OFF signal to
the ignitor to initiate ignition.
D This control uses a quick-to-response learning feature by which the data stored in the ECM
memory is processed in comparison with information from various sensors and switches.
D Thus, the ECM can always perform optimum ignition timing taking into account the output, fuel
consumption, exhaust gas, and other factors for every engine operating condition.
D Ignition control during start-up
Engine speed fluctuates during start of the engine, so the ECM cannot control the ignition timing.
During that period, the ignition timing is fixed at 10° BTDC by using the 10° signal from the crank-
shaft position sensor.

NF0031

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S05

CONTROL SYSTEM
Fuel Injection (Fuel System)

D Ignition control after start of engine

Between the 97° and 65° crank angle signal, the ECM measures the engine speed, and by using
this data it decides the dwell set timing and ignition timing according to the engine condition.

NF0032

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S05

CONTROL SYSTEM
Fuel Injection (Fuel System)

E: IDLE AIR CONTROL

D The ECM activates the idle air control solenoid valve to control the bypass air flowing through
the bypass passage in the throttle body depending on signals from the crankshaft position sensor,
engine coolant temperature sensor, pressure sensor and A/C switch so that the proper idle speed
for each engine load is achieved.
D The idle air control solenoid valve uses a duty-ratio-controlled solenoid which can continuously
vary the opening area of the rotary valve. As the ECM increases the duty ratio, opening of the rotary
valve increases so that the bypass air flow increases, and the engine idling speed becomes higher
as a result.
D The bypass air control is necessary for:
D Increasing idling speed when the air conditioning system and/or electrical loads are turned
on.
D Increasing idling speed during early stage of warm up period.
D Obtaining dashpot function when the throttle valve is quickly closed.
D Prevention of engine speed variation during idling.

NF0033

F: FUEL PUMP CONTROL

Using the signal from the crankshaft position sensor, the ECM controls operation of the fuel pump
by turning its relay ON or OFF. To improve safety, the fuel pump is stopped if the engine stalls with
the ignition switch ON.
Ignition switch ON Fuel pump relay Fuel pump
A certain period of time after ignition switch is turned ON ON Operates
While cranking the engine ON Operates
While engine is operating ON Operates
When engine stops OFF Does not operate

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S06

ON-BOARD DIAGNOSIS SYSTEM

Fuel Injection (Fuel System)

6. On-board Diagnosis System

A: GENERAL
D The on-board diagnosis system detects and indicates a fault by generating a code correspond-
ing to each fault location. The malfunction indicator lamp (CHECK ENGINE light) on the combina-
tion meter indicates occurrence of a fault or abnormality.
D When the malfunction indicator lamp comes on as a result of detection of a fault by the ECM,
the corresponding diagnostic trouble code (DTC) and freeze frame engine condition are stored
in the ECM.
D On the OBD-II conformable car, it is necessary to connect the Subaru Select Monitor (SSM) or
General Scan Tool (GST) to the data link connector in order to check the DTC.
D The SSM and GST can read and erase DTCs. They can also read freeze frame data in addition
to other pieces of engine data.
D If there is a failure involving sensors which may affect drive control of the vehicle, the fail-safe
function ensures minimum level of driveability.

B: FAIL-SAFE FUNCTION
For a sensor or switch which has been judged faulty in the on-board diagnosis, the ECM, if ap-
propriate, generates an associated pseudo signal to keep the vehicle operational. (The control
becomes degraded.)

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S06

ON-BOARD DIAGNOSIS SYSTEM

Fuel Injection (Fuel System)

MEMO

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S-OBD00

SOHC
FUEL INJECTION w/o
(FUEL SYSTEM) FU OBD
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Air Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Fuel Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 FU
4. Sensors and Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 SOHC
–OBD
5. Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6. On-board Diagnosis System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

43
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S-OBD01

GENERAL
Fuel Injection (Fuel System)

1. General
D The Multipoint Fuel Injection (MFI) system supplies optimum air-fuel mixture under every engine
operating condition through the use of the latest electronic control technology.
This system pressurizes the fuel to a constant pressure and injects it into each intake air port in
the cylinder head. The injection quantity of fuel is controlled by an intermittent injection system
where an electro-magnetic injection valve or injector opens for a short period that is precisely con-
trolled depending on the quantity of air appropriate for each condition of operation. In actual con-
trol, an optimum fuel injection quantity is achieved by varying the duration of an electric pulse ap-
plied to the injector. This way of control enables simple, yet highly precise metering of the fuel.
D The engine control module (ECM) that controls the fuel injection system corrects the fuel injec-
tion amount depending on the vehicle speed, throttle opening, coolant temperature and other ve-
hicle-operation-related information. The ECM receives the information in the form of electric sig-
nals from the corresponding sensors and switches.
The MFI system also has the following features:
D Reduced exhaust emissions
D Reduced fuel consumption
D Increased engine output
D Quick response to accelerator and brake pedal operation
D Superior startability and warm-up performance in cold weather due to corrective controls made
according to coolant and intake air temperatures

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. FU_S-OBD02

AIR LINE
Fuel Injection (Fuel System)

2. Air Line
A: GENERAL
The air filtered by the air cleaner enters the throttle body where it is regulated in the volume by the
throttle valve and then enters the intake manifold. It is then distributed to each cylinder where the
air is mixed with fuel injected by the injector. During idling operation, air flows into the cylinder
through the idle air control solenoid valve, bypassing the throttle valve. This enables controlling
the engine idling speed properly.

B: PRESSURE SENSOR
The pressure sensor is connected directly to the throttle body. It continuously measures the abso-
lute pressure of the intake manifold. The sensed pressure is converted into an electrical signal,
and the signal is sent to the ECM. The ECM controls the fuel injection and ignition timing based
on the signal.

S2H0620A

(1) Case (3) O-ring

(2) Terminal (4) Inner lead

FU-3

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AIR LINE
Fuel Injection (Fuel System)

C: INTAKE AIR TEMPERATURE SENSOR

The intake air temperature sensor is mounted on the air cleaner case. It detects using a thermistor
the temperature of the air introduced through the air intake duct. The ECM uses the resistance sig-
nal from the sensor to correct the fuel injection amount according to the temperature of intake air.

B2H1428B

(1) Terminal (3) Thermistor

(2) Housing (4) Connector

D: THROTTLE BODY
D In response to operation of the accelerator pedal, the throttle valve in the throttle body opens/
closes to regulate the volume of the air drawn into the combustion chamber.
D During idling, the throttle valve is almost fully closed and the volume of air passing through the
throttle body is less than that passing through the idle air control solenoid valve.
D More than half of the air necessary for idling is supplied to the intake manifold via the idle air
control solenoid valve which controls properly the engine idling speed, so the idling speed needs
not be adjusted.

FU-4

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AIR LINE
Fuel Injection (Fuel System)

E: THROTTLE POSITION SENSOR

D The throttle position sensor is mounted in the throttle body and linked to the throttle valve.
D The throttle position sensor sends the ECM voltage signal corresponding to the opening of the
throttle valve. When the sensor’s output voltage exceeds a predetermined level, the ECM inter-
prets it as complete closure of the throttle valve. When the output voltage is at another predeter-
mined level, the ECM recognizes that the throttle valve is at a wide open position. Since the output
characteristics of the sensor change over years, the ECM is provided with a learning function to
be able to interpret signals into throttle valve angles always correctly.

S2H0621A

(1) Wave washer (3) Terminal

(2) Return spring (4) Connector

FU-5

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AIR LINE
Fuel Injection (Fuel System)

F: IDLE AIR CONTROL SOLENOID VALVE

D The idle air control solenoid valve is located in the throttle body and regulates the amount of in-
take air that flows bypassing the throttle valve into the intake manifold during engine idling. It is
activated by a signal from the ECM in order to maintain the engine idling speed at a target speed.
D The idle air control solenoid valve is a solenoid-actuated rotary valve consisting of a coil, rotary
valve, spring and housing. The housing is an integral part of the throttle body and provided with
a bypass air port whose opening area is changed by the rotary valve.

NF0397

(1) Connector (3) Air inlet port

(2) Air outlet port (4) Terminal

FU-6

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FUEL LINE
Fuel Injection (Fuel System)

3. Fuel Line
A: GENERAL
D The fuel pressurized by the fuel tank inside pump is delivered to each fuel injector by way of the
fuel pipe and fuel filter. Fuel injection pressure is regulated to an optimum level by the pressure
regulator.
D Each injector injects fuel into the intake port of the corresponding cylinder where the fuel is
mixed with air. The mixture then enters the cylinder.
Fuel injection amount and timing are regulated by the ECM.

NF0445

(1) Purge control solenoid valve (8) Fuel pump A: Fuel line
(2) ECM (9) Jet pump B: Evaporation line
(3) Pressure regulator (10) Fuel cut valve
(4) Fuel injector (11) Fuel tank
(5) Throttle body (12) Two-way valve
(6) Intake manifold (13) Canister
(7) Fuel filter

FU-7

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FUEL LINE
Fuel Injection (Fuel System)

B: PRESSURE REGULATOR
The pressure regulator is installed at the injector end of the fuel supply line. It has a fuel chamber
and spring chamber separated by a diaphragm. Fuel chamber is connected to the fuel supply
line and the spring chamber is connected to the intake manifold. Fuel chamber also has a relief
valve connected to the fuel return line through which fuel returns to the fuel tank. When the intake
manifold vacuum increases, the diaphragm is pulled and the relief valve opens to decrease the
fuel supply line pressure (or fuel injection pressure). When the intake manifold vacuum decreases,
the diaphragm is pushed by the spring to increase the fuel supply line pressure. Thus, the differ-
ence between the fuel injection pressure and the intake manifold vacuum is kept at a constant level
of 294 kPa (3.00 kgf/cm2, 43.0 psi) to precisely control the amount of injected fuel.

S2H0623C

(1) Relief valve A: To intake manifold

(2) Diaphragm B: Fuel IN
C: Fuel OUT

FU-8

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FUEL LINE
Fuel Injection (Fuel System)

C: FUEL INJECTORS
D The MFI system employs top feed type fuel injectors.
D Each injector is installed in the fuel pipe in such a way that the injector is cooled by fuel.
D The features of this type of fuel injector are as follows:
1) High heat resistance
2) Low driving noise
3) Easy to service
4) Small size
D The injector injects fuel according to the valve open signal from the ECM. The needle valve is
lifted by the solenoid which is energized on arrival of the valve open signal.
D Since the injector’s nozzle hole area, the lift of valve and the fuel pressure are kept constant, the
amount of fuel injected is controlled only by varying the duration of the valve open signal from the
ECM.

S2H0624A

(1) Filter (3) Cover

(2) Plunger (4) Connector

FU-9

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FUEL LINE
Fuel Injection (Fuel System)

D: FUEL TANK
The fuel tank utilizes a two-compartment design to ensure sufficient capacity without interfering
with the rear differential. It is provided with a suction jet pump (included in the fuel pump and fuel
level sensor assembly) which transfers fuel from one compartment to the other. Each compartment
has an individual fuel level sensor.
The fuel tank is located under the rear seat and secured with hold-down bands.

NF0325

(1) Fuel pump and fuel level sensor assembly (4) Cushion
(2) Fuel sub level sensor (5) Steel
(3) Band

FU-10

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FUEL LINE
Fuel Injection (Fuel System)

E: FUEL PUMP AND FUEL LEVEL SENSOR ASSEMBLY

1. FUEL PUMP
The fuel pump consists of a motor, impeller, pump casing, pump cover, check valve and filter. It
is located in the fuel tank and combined with the fuel level sensor into a single unit. The operation
of this impeller type pump is very quiet.

S2H1957B

(1) Fuel pump A: From engine (return line)

(2) Fuel level sensor B: From sub tank
(3) Jet pump C: To engine (delivery line)
(4) Mesh filter D: Suction
(5) Impeller E: Discharge
(6) Check valve
(7) Pump casing
(8) Motor armature
(9) Vane groove

D When the ignition switch is turned ON, fuel pump relay is activated. Then the motor operates
to rotate the impeller.
D As the impeller rotates, fuel in a vane groove of the impeller flows along the fuel passage into
the next vane groove by centrifugal force. When fuel flows from one groove to the next, a pressure
difference occurs due to friction. This creates a pumping effect.
D The fuel pushed up by rotation of the impeller then passes through the clearance between the
armature and the magnet of the motor and is discharged through the check valve.
D When the fuel discharge pressure reaches the specified level, the relief valve opens and excess
fuel is released into the fuel tank. In this manner, the relief valve prevents an abnormal increase
in fuel pressure.
D When the engine and the fuel pump stop, spring force acts on the check valve to close the dis-
charge port, so that the fuel pressure in the fuel delivery line is retained.

FU-11

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FUEL LINE
Fuel Injection (Fuel System)

2. FUEL LEVEL SENSOR

The fuel level sensor forms part of the fuel pump and located in the fuel tank. The sensor outputs
an electric resistance signal that varies with movement of its float to indicate the level of the fuel
remaining in the tank.

S2H2178A

(1) Fuel level sensor

(2) Float

FU-12

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FUEL LINE
Fuel Injection (Fuel System)

3. JET PUMP
D The jet pump utilizes the velocity of fuel returning from the engine to produce negative pressure
in it.
D Using the pumping effect produced by the negative pressure, the jet pump transfers fuel from
the sub-compartment to the main compartment of the fuel tank.
D When the return line nozzle is clogged, the fuel sent back through the return line flows back into
the fuel tank via the relief valve.

NF0328

(1) Relief valve A: Return line

(2) Nozzle

FU-13

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FUEL LINE
Fuel Injection (Fuel System)

F: SUB-COMPARTMENT FUEL LEVEL SENSOR

This sensor detects the level of the fuel in the sub-compartment (the compartment in which the
fuel pump is not located) and acts as part of the fuel transfer line when the jet pump is in operation
to maintain the fuel in both compartments at the same level.

NF0396

(1) Fuel level sensor A: To jet pump

(2) Float

G: FUEL FILTER
The fuel filter located in the engine compartment is a pressure-withstanding, cartridge type. It has
a filter element in a metal case. The fuel entering the filter flows from the perimeter of the element
to the center of the filter and goes out from there.

NF0018

FU-14

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

4. Sensors and Switches

A: OXYGEN SENSOR (WITH CATALYTIC CONVERTER)
D The oxygen sensor is used to sense oxygen concentration in the exhaust gas. If the air-fuel ratio
is leaner than the stoichiometric ratio in the mixture (i.e., excessive amount of air), the exhaust gas
contains more oxygen. To the contrary, if the fuel ratio is richer than the stoichiometric ratio, the
exhaust gas contains almost no oxygen.
D Detecting the oxygen concentration in exhaust gas using the oxygen sensor makes it possible
to determine whether the air-fuel ratio is leaner or richer than the stoichiometry.
D The oxygen sensor has a zirconia tube (ceramic) which generates voltage if there is a difference
in oxygen ion concentration between the inside and outside of the tube. Platinum is coated on the
inside and outside of the zirconia tube as a catalysis and electrode material. The sensor housing
is grounded to the exhaust pipe and the inside is connected to the ECM through the harness.
D A ceramic heater is employed to improve performance at low temperatures.

H2H1224C

(1) Protection tube (4) Gasket

(2) Ceramic heater (5) Sensor housing
(3) Zirconia tube (6) Harness

FU-15

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D When rich air-fuel mixture is burnt in the cylinder, the oxygen in the exhaust gases is almost com-
pletely used in the catalytic reaction by the platinum coating on the external surface of the zirconia
tube. This results in a very large difference in the oxygen ion concentration between the inside and
outside of the tube, and the electromotive force generated is large.
D When a lean air-fuel mixture is burnt in the cylinder, relatively large amount of oxygen remains
in the exhaust gases even after the catalytic action, and this results in a small difference in the oxy-
gen ion concentration between the tube’s internal and external surfaces. The electromotive force
in this case is very small.
D The difference in oxygen concentration changes drastically in the vicinity of the stoichiometric
air-fuel ratio, and hence the change in the electromotive force is also large. By using this informa-
tion, the ECM can determine the air-fuel ratio of the supplied mixture easily. The oxygen sensor
does not generate much electromotive force when the temperature is low. The output characteris-
tics of the sensor stabilize at a temperature of approximately 300 to 400°C (572 to 752°F).

NF0333

FU-16

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

B: ENGINE COOLANT TEMPERATURE SENSOR

The engine coolant temperature sensor is located on the engine coolant pipe. The sensor uses
a thermistor whose resistance changes inversely with temperature. Resistance signals as engine
coolant temperature information are transmitted to the ECM to make fuel injection, ignition timing,
purge control solenoid valve and other controls.

S2H1113B

(1) Connector (2) Thermistor element

FU-17

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

C: CRANKSHAFT POSITION SENSOR

D The crankshaft position sensor is installed on the oil pump which is located in the front center
portion of the cylinder block. The sensor generates a pulse when one of the teeth on the perimeter
of the crankshaft sprocket (rotating together with the crankshaft) passes in front of it. The ECM de-
termines the crankshaft angular position by counting the number of pulses.
D The crankshaft position sensor is a molded type which consists of a magnet, core, coil, terminals
and other components as illustrated below.

NF0024

(1) Terminal (4) Coil

(2) Yoke core (5) Core
(3) Magnet (6) Cover

FU-18

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D As the crankshaft rotates, each tooth aligns with the crankshaft position sensor. At that time, the
magnetic flux in the sensor’s coil changes since the air gap between the sensor pickup and the
sprocket changes. This change in magnetic flux induces a voltage pulse in the sensor and the
pulse is transmitted to the ECM.

B2H1994B

(1) Crankshaft position sensor A: Crankshaft half rotation

(2) Crankshaft sprocket

FU-19

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D: KNOCK SENSOR
D The knock sensor is installed on the cylinder block, and senses knocking that occurs in the en-
gine.
D The sensor is a piezo-electric type which converts vibration resulting from knocking into electric
signals.
D In addition to a piezo-electric element, the sensor has a weight and case as its components.
If knocking occurs in the engine, the weight in the case moves causing the piezo-electric element
to generate a voltage.
D The knock sensor harness is connected to the bulkhead harness.

B2H1998B

(1) Nut A: To knock sensor harness

(2) Weight
(3) Resistor
(4) Housing
(5) Piezo-electric element

FU-20

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

E: VEHICLE SPEED SENSOR

1. MT VEHICLES
D The vehicle speed sensor is mounted on the transmission.
D The vehicle speed sensor generates a 4-pulse signal for every rotation of the front differential
and send it to the ECM and the combination meter.

B2H2458C

(1) Combination meter

(2) ECM
(3) Vehicle speed sensor
(4) Transmission

FU-21

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

2. AT VEHICLES
D The vehicle speed sensor is mounted on the transmission.
D The vehicle speed sensor generates a 16-pulse signal for every rotation of the front differential
and send it to the transmission control module (TCM). The signal sent to the TCM is converted
there into a 4-pulse signal, and then sent to the ECM and the combination meter.

B2H2459B

(1) Combination meter

(2) ECM
(3) TCM
(4) Vehicle speed sensor
(5) Transmission

FU-22

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CONTROL SYSTEM
Fuel Injection (Fuel System)

5. Control System
A: GENERAL
The ECM receives signals from various sensors, switches, and other control modules. Using these
signals, it determines the engine operating conditions and if necessary, emits signals to one or
more systems to control them for optimum operation.
Major control items of the ECM are as follow:
D Fuel injection control
D Ignition system control
D Idle air control
D Fuel pump control
D Canister purge control*1
D Radiator fan control*2
D Air conditioner cut control*3
D On-board diagnosis function

*1: Canister purge control is described under “EC (SOHC) – Emission Control (Aux. Emission Con-
trol Devices) Evaporative Emission Control System”.
*2: Radiator fan control is described under “CO – Cooling”.
*3: Air conditioner cut control is described under “AC – HVAC System (Heater, Ventilator and A/C)”.

FU-23

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CONTROL SYSTEM
Fuel Injection (Fuel System)

B: INPUT AND OUTPUT SIGNALS

Signal Unit Function
Intake air temperature sensor Detects the temperature of intake air.
Throttle position sensor Detects the throttle valve position.
Oxygen sensor Detects the density of oxygen in exhaust gases.
Crankshaft position sensor Detects the crankshaft angular position.
Engine coolant temperature sensor Detects the engine coolant temperature.
Knock sensor Detects engine knocking.
Vehicle speed sensor Detects the vehicle speed.
Ignition switch Detects operation of the ignition switch.
Input signals
Starter switch Detects the condition of engine cranking.
Park/Neutral position switch (AT) Detects shift positions.
Neutral position switch (MT) Detects that the gear is in neutral.
Torque control signal (AT) Controls engine torque.
Pressure sensor Detects atmospheric pressure and intake manifold pressure.
Heater circuit of oxygen sensor Detects abnormality in the heater circuit of the oxygen sensors.
Diagnostics of TCM Detects the self-diagnostics of the TCM.
A/C switch Detects ON-OFF operation of the A/C switch.
Fuel Injector Activates an injector.
Ignition signal Turns the primary ignition current ON or OFF.
Fuel pump relay Turns the fuel pump relay ON or OFF.
A/C control relay Turns the A/C control relay ON or OFF.
Radiator fan control relay Turns the radiator fan control relay ON or OFF.
Output signals
Adjusts the amount of air flowing through the bypass line in the
Idle air control solenoid valve
throttle body.
Malfunction indicator lamp Indicates existence of abnormality.
Purge control solenoid valve Controls purge of evaporative gas absorbed by the canister.
Power supply Control ON/OFF of the main power supply relay.

FU-24

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CONTROL SYSTEM
Fuel Injection (Fuel System)

C: FUEL INJECTION CONTROL

D The ECM receives signals from various sensors to control both the amount of fuel injected and
the timing at which the fuel is injected. The fuel injection control system operates according to the
grouped fuel injection control principle, i.e., the fuel is injected simultaneously into a pair of cylin-
ders (either No. 1 and No. 2 cylinders or No. 3 and No. 4 cylinders). The grouped fuel injection
control is used in all engine operating phases except during engine start.
D The amount of fuel injected depends upon the length of time the injector stays open. The fuel
injection duration is determined according to varying operating condition of the engine. For the
purpose of achieving highly responsive and accurate fuel injection duration control, the ECM per-
forms a new feedback control that incorporates a learning feature as detailed later.
D The grouped fuel injection control is performed such that fuel is injected accurately at the time
when the maximum air intake efficiency can be achieved for each cylinder (i.e., fuel injection is
completed just before the intake valve begins to open).

1. FUEL INJECTION DURATION

Fuel injection duration is basically determined as indicated below:
D During engine start-up:
The duration defined below is used.
D Duration of fuel injection during engine start-up ..... Determined according to the engine cool-
ant temperature detected by the engine coolant temperature sensor.
D During normal operation:
The duration is determined as follows:
Basic duration of fuel injection x Correction factors + Voltage correction time
D Basic duration of fuel injection ..... The basic length of time fuel is injected. This is determined
based on the amount of intake air calculated from the intake air temperature sensor signal, pres-
sure sensor signal and the engine speed (rpm) signal from the crankshaft position sensor.
D Correction factors ..... See the next section.
D Voltage correction time ..... This is added to compensate for the time lag before operation of
injector that results from variation in the battery voltage.

FU-25

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CONTROL SYSTEM
Fuel Injection (Fuel System)

2. CORRECTION FACTORS
The following factors are used to correct the basic duration of fuel injection in order to make the
air-fuel ratio meet the requirements of varying engine operating conditions:
D Air-fuel ratio feedback factor:
An optimum air-fuel ratio factor is assigned to each engine speed and intake manifold pressure
combination.

S2H0856A

D Start increment factor:

This factor is used to increase the fuel injection duration only while the engine is being cranked
to improve its startability.

G2H0045

FU-26

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CONTROL SYSTEM
Fuel Injection (Fuel System)

D Coolant-temperature-dependent increment factor:

This factor is used to increase the fuel injection duration depending on engine coolant temperature
signals to facilitate cold starting. The lower the coolant temperature, the greater the increment.

Coolant-temperature-dependentincrement

Coolant-temperature-dependentincrementcharacteristic
B2H0147A

D Air temperature increment factor:

The air density varies with the temperature of the intake air, which in turn changes the air-fuel ratio.
The air temperature increment factor corrects changes in the air-fuel ratio due to change in the
air density. When the intake air temperature is high, the injector opening time is shortened, and
vice versa.

M2H0169

FU-27

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CONTROL SYSTEM
Fuel Injection (Fuel System)

3. AIR-FUEL RATIO FEEDBACK FACTOR (WITH CATALYTIC CONVERTER)

The ECM creates this factor utilizing the oxygen sensor signal. When the signal voltage is low, the
air-fuel ratio is richer than the stoichiometric ratio. The ECM then makes the fuel injection duration
shorter by modifying the factor. When the voltage is high showing that the mixture is lean, the ECM
modifies the factor to make the injection duration longer. In this way, the air-fuel ratio is maintained
at a level close to the stoichiometric ratio at which the three-way catalyst acts most effectively.

H2H1873C

(1) Front catalyst A: Injection duration increment signal

(2) Exhaust gas B: Injection duration decrement signal
(3) Oxygen sensor C: High oxygen density
(4) Fuel injector D: Low oxygen density
(5) Combustion chamber E: Lean signal
(6) ECM F: Rich signal

4. LEARNING FEATURE (WITH CATALYTIC CONVERTER)

The air-fuel ratio feedback control includes a learning feature which contributes to more accurate
and responsive control.
D In the air-fuel ratio feedback control, the ECM calculates the necessary amount of correction
based on data from the oxygen sensor and adds the result to the basic duration (which is stored
in the ECM’s memory for each condition defined by the engine speed and various loads.)
D Without a learning feature, the ECM carries out the above-mentioned process every time. This
means that if the amount of necessary correction is large, the air-fuel ratio feedback control be-
comes less responsive and less accurate.
D The learning feature enables the ECM to store the amount of correction into memory and add
it to the basic fuel injection duration to create a new reference fuel injection duration. Using the
reference duration as the basic duration for the injection a few times later, the ECM can reduce
the amount of correction and thus make its feedback control more accurate and responsive to
changes in the air-fuel ratio due to difference in driving condition and sensor/actuator characteris-
tics that may result from unit-to-unit variation or aging over time.

FU-28

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CONTROL SYSTEM
Fuel Injection (Fuel System)

D: IGNITION SYSTEM CONTROL

D The ECM determines operating condition of the engine based on signals from the pressure sen-
sor, engine coolant temperature sensor, intake air temperature sensor, crankshaft position sensor
and other sources. It then selects the ignition timing most appropriate for the condition thus deter-
mined from those stored in its memory and outputs at that timing a primary current OFF signal to
the ignitor to initiate ignition.
D This control uses a quick-to-response learning feature by which the data stored in the ECM
memory is processed in comparison with information from various sensors and switches.
D Thus, the ECM can always perform optimum ignition timing taking into account the output, fuel
consumption, exhaust gas, and other factors for every engine operating condition.
D Ignition control during start-up
Engine speed fluctuates during start of the engine, so the ECM cannot control the ignition timing.
During that period, the ignition timing is fixed at 10° BTDC by using the 10° signal from the crank-
shaft position sensor.

Ignition coil and

ignitor assembly

S2H1812B

FU-29

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CONTROL SYSTEM
Fuel Injection (Fuel System)

D Within the ranges (A), the crank angle signal is input every 10° rotation of the crankshaft.
D The discrimination between a cylinder group and the other is accomplished by detecting the
ranges (B) and (C) where no signal is input.
D The ECM judges that the No. 1 and No. 2 cylinders are at TDC when it detects the range (B),
and that the No. 3 and No. 4 cylinders are at TDC when it detects the range (C).

B2H2007B

(1) Cylinder number (TDC)

(2) Crank angle pulse
(3) Ignition timing at starting
(4) Ignition timing at normal condition
(5) Burning cylinder

FU-30

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CONTROL SYSTEM
Fuel Injection (Fuel System)

E: IDLE AIR CONTROL

D The ECM activates the idle air control solenoid valve to control the bypass air flowing through
the bypass passage in the throttle body depending on signals from the crankshaft position sensor,
engine coolant temperature sensor, pressure sensor and A/C switch so that the proper idle speed
for each engine load is achieved.
D The idle air control solenoid valve uses a duty-ratio-controlled solenoid which can continuously
vary the opening area of the rotary valve. As the ECM increases the duty ratio, opening of the rotary
valve increases so that the bypass air flow increases, and the engine idling speed becomes higher
as a result.
D The bypass air control is necessary for:
D Increasing idling speed when the air conditioning system and/or electrical loads are turned
on.
D Increasing idling speed during early stage of warm up period.
D Obtaining dashpot function when the throttle valve is quickly closed.
D Prevention of engine speed variation during idling.

Intake air temperature sensor

Intake manifold pressure sensor

B2H3450D

F: FUEL PUMP CONTROL

Using the signal from the crankshaft position sensor, the ECM controls operation of the fuel pump
by turning its relay ON or OFF. To improve safety, the fuel pump is stopped if the engine stalls with
the ignition switch ON.
Ignition switch ON Fuel pump relay Fuel pump
A certain period of time after ignition switch is turned ON ON Operates
While cranking the engine ON Operates
While engine is operating ON Operates
When engine stops OFF Does not operate

FU-31

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CONTROL SYSTEM
Fuel Injection (Fuel System)

G: POWER SUPPLY CONTROL

D When the ECM receives an ON signal from the ignition switch, current flows through the main
relay. This turns the ignition relay ON so that power is supplied to the ignition coil, pressure sensor,
idle air control solenoid valve, etc.
D Power to the above components is turned off five seconds after the ECM receives an OFF signal
from the ignition switch. The fuel injectors stop fuel injection immediately after the ignition switch
is turned OFF because the injection signal is cut off.

FU-32

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ON-BOARD DIAGNOSIS SYSTEM

Fuel Injection (Fuel System)

6. On-board Diagnosis System

A: GENERAL
D The on-board diagnosis system detects and indicates a fault by generating a code correspond-
ing to each fault location. The malfunction indicator lamp (CHECK ENGINE light) on the combina-
tion meter indicates occurrence of a fault or abnormality.
D When the malfunction indicator lamp comes on as a result of detection of a fault by the ECM,
the corresponding diagnostic trouble code (DTC) and freeze frame engine condition are stored
in the ECM.
D The Subaru Select Monitor (SSM) can read and erase DTCs. It can also read freeze frame data
in addition to other pieces of engine data.
D If there is a failure involving sensors which may affect drive control of the vehicle, the fail-safe
function ensures minimum level of driveability.

B: FAIL-SAFE FUNCTION
For a sensor or switch which has been judged faulty in the on-board diagnosis, the ECM, if ap-
propriate, generates an associated pseudo signal to keep the vehicle operational. (The control
becomes degraded.)

FU-33

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ON-BOARD DIAGNOSIS SYSTEM

Fuel Injection (Fuel System)

MEMO

FU-34

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FUEL INJECTION DOHC

(FUEL SYSTEM) FU TURBO
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Air Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Fuel Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Sensors and Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5. Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6. On-board Diagnosis System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 FU
DOHC

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GENERAL
Fuel Injection (Fuel System)

1. General
D The Multipoint Fuel Injection (MFI) system supplies optimum air-fuel mixture under every engine
operating condition through the use of the latest electronic control technology.
This system pressurizes the fuel to a constant pressure and injects it into each intake air port in
the cylinder head. The injection quantity of fuel is controlled by an intermittent injection system
where an electro-magnetic injection valve or injector opens for a short period that is precisely con-
trolled depending on the quantity of air appropriate for each condition of operation. In actual con-
trol, an optimum fuel injection quantity is achieved by varying the duration of an electric pulse ap-
plied to the injector. This way of control enables simple, yet highly precise metering of the fuel.
D The engine control module (ECM) that controls the fuel injection system corrects the fuel injec-
tion amount depending on the vehicle speed, throttle opening, coolant temperature and other ve-
hicle-operation-related information. The ECM receives the information in the form of electric sig-
nals from the corresponding sensors and switches.
The MFI system also has the following features:
D Reduced exhaust emissions
D Reduced fuel consumption
D Increased engine output
D Quick response to accelerator and brake pedal operation
D Superior startability and warm-up performance in cold weather due to corrective controls made
according to coolant and intake air temperatures

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AIR LINE
Fuel Injection (Fuel System)

2. Air Line
A: GENERAL
The air filtered by the air cleaner enters the throttle body where it is regulated in the volume by the
throttle valve and then enters the intake manifold. It is then distributed to each cylinder where the
air is mixed with fuel injected by the injector. During idling operation, air flows into the cylinder
through the idle air control solenoid valve, bypassing the throttle valve. This enables controlling
the engine idling speed properly.

B: PRESSURE SENSOR
The pressure sensor is attached to the top of the throttle body, and continuously sends to the en-
gine control module (ECM) voltage signals that are proportional to intake manifold absolute pres-
sures. The ECM controls the fuel injection and ignition timing based on the intake manifold abso-
lute pressure signals in addition to other signals from many sensors and other control modules.

NF0318

C: THROTTLE BODY
D In response to operation of the accelerator pedal, the throttle valve in the throttle body opens/
closes to regulate the volume of the air drawn into the combustion chamber.
D During idling, the throttle valve is almost fully closed and the volume of air passing through the
throttle body is less than that passing through the idle air control solenoid valve.
D More than half of the air necessary for idling is supplied to the intake manifold via the idle air
control solenoid valve which controls properly the engine idling speed, so the idling speed needs
not be adjusted.

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AIR LINE
Fuel Injection (Fuel System)

D: THROTTLE POSITION SENSOR

D The throttle position sensor is mounted in the throttle body and linked to the throttle valve.
D The throttle position sensor sends the ECM voltage signal corresponding to the opening of the
throttle valve. When the sensor’s output voltage exceeds a predetermined level, the ECM inter-
prets it as complete closure of the throttle valve. When the output voltage is at another predeter-
mined level, the ECM recognizes that the throttle valve is at a wide open position. Since the output
characteristics of the sensor change over years, the ECM is provided with a learning function to
be able to interpret signals into throttle valve angles always correctly.

NF0319

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AIR LINE
Fuel Injection (Fuel System)

E: IDLE AIR CONTROL SOLENOID VALVE

D The idle air control solenoid valve is located in the throttle body and regulates the amount of in-
take air that flows bypassing the throttle valve into the intake manifold during engine idling. It is
activated by a signal from the ECM in order to maintain the engine idling speed at a target speed.
D The idle air control solenoid valve is a solenoid-actuated rotary valve consisting of a coil, rotary
valve, spring and housing. The housing is an integral part of the throttle body and provided with
a bypass air port whose opening area is changed by the rotary valve.

NF0397

(1) Connector (3) Air inlet port

(2) Air outlet port (4) Terminal

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AIR LINE
Fuel Injection (Fuel System)

F: MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR

The mass air flow and the intake air temperature sensors are integrated into a single unit. The unit
is mounted on the air cleaner case and measures the amount as well as the temperature of the
intake air.
The measured amount and temperature are converted into electrical signals and sent to the ECM.
The ECM uses these signals to control injection and ignition timing as well as the fuel injection
amount.

NF0321

(1) Mass air flow and the intake air temperature A: Air
sensor unit
(2) Mass air flow sensor
(3) Intake air temperature sensor

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AIR LINE
Fuel Injection (Fuel System)

G: TUMBLE GENERATOR VALVES

D A tumble generator valve is provided on each engine bank, between the intake manifold and
intake air ports. The right bank tumble generator valve has butterfly valves for the #1 and #3 cylin-
ders and the left bank tumble generator valve has those for the #2 and #4 cylinders. The two butter-
fly valves in each tumble generator valve are fitted on a single shaft that is driven by an actuator.
D The tumble generator valves are controlled by the ECM according to the coolant temperature
and the time elapsed after start of the engine. When the engine is started, the butterfly valves are
moved to the closing ends. In this state, the intake air flows at very high speeds passing through
narrowed passages in the directions determined by the individual intake air ports in the cylinder
head. This creates tumbling air motions in the cylinders, which enables lean mixtures to be ignited
and thus harmful exhaust emissions to be reduced during engine start. The tumble generator
valves are fully open when the engine is operating at an ordinary driving speed, allowing intake
air to flow without being changed in direction and velocity.

NF0322

(A) Activated
(B) Not activated
(1) Actuator (6) Tumble generating air passage
(2) Tumble generator valve position sensor (7) Intake main air passage
(3) Tumble generator housing (8) Piston
(4) Intake manifold (9) Injector
(5) Tumble generator valve (10) Cylinder head

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FUEL LINE
Fuel Injection (Fuel System)

3. Fuel Line
A: GENERAL
D The fuel pressurized by the fuel tank inside pump is delivered to each fuel injector by way of the
fuel pipe and fuel filter. Fuel injection pressure is regulated to an optimum level by the pressure
regulator.
D Each injector injects fuel into the intake port of the corresponding cylinder where the fuel is
mixed with air. The mixture then enters the cylinder.
Fuel injection amount and timing are regulated by the ECM.

NF0323

(1) Purge control solenoid valve (7) Fuel pump A: Fuel line
(2) Purge valve (8) Jet pump B: Evaporation line
(3) Pressure regulator (9) Fuel cut valve
(4) Throttle body (10) Canister
(5) Fuel filter (11) Two-way valve
(6) Intake manifold (12) ECM

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FUEL LINE
Fuel Injection (Fuel System)

B: PRESSURE REGULATOR
The pressure regulator is installed at the injector end of the fuel supply line. It has a fuel chamber
and spring chamber separated by a diaphragm. Fuel chamber is connected to the fuel supply
line and the spring chamber is connected to the intake manifold. Fuel chamber also has a relief
valve connected to the fuel return line through which fuel returns to the fuel tank. When the intake
manifold vacuum increases, the diaphragm is pulled and the relief valve opens to decrease the
fuel supply line pressure (or fuel injection pressure). When the intake manifold vacuum decreases,
the diaphragm is pushed by the spring to increase the fuel supply line pressure. Thus, the differ-
ence between the fuel injection pressure and the intake manifold vacuum is kept at a constant level
of 294 kPa (3.00 kgf/cm2, 43.0 psi) to precisely control the amount of injected fuel.

NF0387

A: To intake manifold (1) Relief valve

B: Fuel IN (2) Diaphragm
C: Fuel OUT

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FUEL LINE
Fuel Injection (Fuel System)

C: FUEL INJECTORS
D The MFI system employs top feed type fuel injectors.
D Each injector is installed in the fuel pipe in such a way that the injector is cooled by fuel.
D The features of this type of fuel injector are as follows:
1) High heat resistance
2) Low driving noise
3) Easy to service
4) Small size
D The injector injects fuel according to the valve open signal from the ECM. The needle valve is
lifted by the solenoid which is energized on arrival of the valve open signal.
D Since the injector’s nozzle hole area, the lift of valve and the fuel pressure are kept constant, the
amount of fuel injected is controlled only by varying the duration of the valve open signal from the
ECM.
D The multi-hole nozzle makes it possible for the injector to produce fire fuel particles, which en-
hances the combustion efficiency and output performance of the engine.

NF0388

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FUEL LINE
Fuel Injection (Fuel System)

D: FUEL TANK
The fuel tank utilizes a two-compartment design to ensure sufficient capacity without interfering
with the rear differential. It is provided with a suction jet pump (included in the fuel pump and fuel
level sensor assembly) which transfers fuel from one compartment to the other. Each compartment
has an individual fuel level sensor.
The fuel tank is located under the rear seat and secured with hold-down bands.

NF0325

(1) Fuel pump and fuel level sensor assembly (4) Cushion
(2) Fuel sub level sensor (5) Steel
(3) Band

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FUEL LINE
Fuel Injection (Fuel System)

E: FUEL PUMP AND FUEL LEVEL SENSOR ASSEMBLY

1. FUEL PUMP
The fuel pump consists of a motor, impeller, pump casing, pump cover, check valve and filter. It
is located in the fuel tank and combined with the fuel level sensor into a single unit. The operation
of this impeller type pump is very quiet.

NF0326

(1) Fuel pump (9) Suction

(2) Fuel level sensor (10) Discharge
(3) Jet pump (11) Vane groove
(4) Mesh filter
(5) Impeller A: From engine (return line)
(6) Check valve B: From sub tank
(7) Pump casing C: To engine (delivery line)
(8) Motor armature

D When the ignition switch is turned ON, fuel pump relay is activated. Then the motor operates
to rotate the impeller.
D As the impeller rotates, fuel in a vane groove of the impeller flows along the fuel passage into
the next vane groove by centrifugal force. When fuel flows from one groove to the next, a pressure
difference occurs due to friction. This creates a pumping effect.
D The fuel pushed up by rotation of the impeller then passes through the clearance between the
armature and the magnet of the motor and is discharged through the check valve.
D When the fuel discharge pressure reaches the specified level, the relief valve opens and excess
fuel is released into the fuel tank. In this manner, the relief valve prevents an abnormal increase
in fuel pressure.
D When the engine and the fuel pump stop, spring force acts on the check valve to close the dis-
charge port, so that the fuel pressure in the fuel delivery line is retained.

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FUEL LINE
Fuel Injection (Fuel System)

2. FUEL LEVEL SENSOR

The fuel level sensor forms part of the fuel pump and located in the fuel tank. The sensor outputs
an electric resistance signal that varies with movement of its float to indicate the level of the fuel
remaining in the tank.

NF0327

(1) Fuel level sensor

(2) Float

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FUEL LINE
Fuel Injection (Fuel System)

3. JET PUMP
D The jet pump utilizes the velocity of fuel returning from the engine to produce negative pressure
in it.
D Using the pumping effect produced by the negative pressure, the jet pump transfers fuel from
the sub-compartment to the main compartment of the fuel tank.
D When the return line nozzle is clogged, the fuel sent back through the return line flows back into
the fuel tank via the relief valve.

NF0328

(1) Relief valve A: Return line

(2) Nozzle

FU-14

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FUEL LINE
Fuel Injection (Fuel System)

F: SUB-COMPARTMENT FUEL LEVEL SENSOR

This sensor detects the level of the fuel in the sub-compartment (the compartment in which the
fuel pump is not located) and acts as part of the fuel transfer line when the jet pump is in operation
to maintain the fuel in both compartments at the same level.

NF0396

(1) Fuel level sensor A: To jet pump

(2) Float

G: FUEL FILTER
The fuel filter located in the engine compartment is a pressure-withstanding, cartridge type. It has
a filter element in a metal case. The fuel entering the filter flows from the perimeter of the element
to the center of the filter and goes out from there.

NF0018

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

4. Sensors and Switches

A: FRONT OXYGEN (A/F) SENSOR
D The front oxygen sensor uses zirconium oxide (ZrO2) which is a solid electrolyte, at portions ex-
posed to exhaust gas.
D The zirconium oxide has the property of generating electromotive force when its both sides are
exposed to oxygen ions of different concentration and the magnitude of this electromotive force
depends on how much the difference is.
D The front oxygen sensor detects the amount of oxygen in exhaust gases by making use of this
property of the zirconium oxide material.
D The zirconium oxide material is formed into a closed end tube and its external surface is ex-
posed to exhaust gases with smaller oxygen ion concentration, whereas its internal surface is ex-
posed to atmospheric air. The external surface has a porous platinum coating. The sensor housing
is grounded to the exhaust pipe and the inside is connected to the ECM through the harness to
be able to use the current output from the sensor.
D The sensor incorporates a ceramic heater to improve its performance at low temperatures.

NF0389

(1) Protection tube (3) Sensor housing

(2) Gasket (4) Ceramic heater

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D When rich air-fuel mixture is burnt in the cylinder, the oxygen in the exhaust gases is almost com-
pletely used in the catalytic reaction by the platinum coating on the external surface of the zirconia
tube. This results in a very large difference in the oxygen ion concentration between the inside and
outside of the tube, and the electromotive force generated is large.
D When a lean air-fuel mixture is burnt in the cylinder, relatively large amount of oxygen remains
in the exhaust gases even after the catalytic action, and this results in a small difference in the oxy-
gen ion concentration between the tube’s internal and external surfaces. The electromotive force
in this case is very small.
D The difference in oxygen concentration changes drastically in the vicinity of the stoichiometric
air-fuel ratio, and hence the change in the electromotive force is also large. By using this informa-
tion, the ECM can determine the air-fuel ratio of the supplied mixture easily. The front oxygen sen-
sor does not generate much electromotive force when the temperature is low. The output charac-
teristics of the sensor stabilize at a temperature of approximately 700°C (1,292°F).

NF0331

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

B: REAR OXYGEN SENSOR

D The rear oxygen sensor is used to sense oxygen concentration in the exhaust gas. If the air-fuel
ratio is leaner than the stoichiometric ratio in the mixture (i.e., excessive amount of air), the exhaust
gas contains more oxygen. To the contrary, if the fuel ratio is richer than the stoichiometric ratio,
the exhaust gas contains almost no oxygen.
D Detecting the oxygen concentration in exhaust gas using the oxygen sensor makes it possible
to determine whether the air-fuel ratio is leaner or richer than the stoichiometry.
D The rear oxygen sensor has a zirconia tube (ceramic) which generates voltage if there is a differ-
ence in oxygen ion concentration between the inside and outside of the tube. Platinum is coated
on the inside and outside of the zirconia tube as a catalysis and electrode material. The sensor
housing is grounded to the exhaust pipe and the inside is connected to the ECM through the har-
ness.
D A ceramic heater is employed to improve performance at low temperatures.

NF0390

(1) Protection tube (4) Ceramic heater

(2) Gasket (5) Zirconia tube
(3) Sensor housing

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D When rich air-fuel mixture is burnt in the cylinder, the oxygen in the exhaust gases is almost com-
pletely used in the catalytic reaction by the platinum coating on the external surface of the zirconia
tube. This results in a very large difference in the oxygen ion concentration between the inside and
outside of the tube, and the electromotive force generated is large.
D When a lean air-fuel mixture is burnt in the cylinder, relatively large amount of oxygen remains
in the exhaust gases even after the catalytic action, and this results in a small difference in the oxy-
gen ion concentration between the tube’s internal and external surfaces. The electromotive force
in this case is very small.
D The difference in oxygen concentration changes drastically in the vicinity of the stoichiometric
air-fuel ratio, and hence the change in the electromotive force is also large. By using this informa-
tion, the ECM can determine the air-fuel ratio of the supplied mixture easily. The rear oxygen sensor
does not generate much electromotive force when the temperature is low. The output characteris-
tics of the sensor stabilize at a temperature of approximately 300 to 400°C (572 to 752°F).

NF0333

FU-19

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

C: ENGINE COOLANT TEMPERATURE SENSOR

The engine coolant temperature sensor is located on the engine coolant pipe. The sensor uses
a thermistor whose resistance changes inversely with temperature. Resistance signals as engine
coolant temperature information are transmitted to the ECM to make fuel injection, ignition timing,
purge control solenoid valve and other controls.

S2H1113B

(1) Connector (2) Thermistor element

D: EXHAUST GAS TEMPERATURE SENSOR

The exhaust gas temperature sensor is located on the joint pipe and used to monitor the condition
of the precatalytic converter.

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

E: CRANKSHAFT POSITION SENSOR

D The crankshaft position sensor is installed on the oil pump which is located in the front center
portion of the cylinder block. The sensor generates a pulse when one of the teeth on the perimeter
of the crankshaft sprocket (rotating together with the crankshaft) passes in front of it. The ECM de-
termines the crankshaft angular position by counting the number of pulses.
D The crankshaft position sensor is a molded type which consists of a magnet, core, coil, terminals
and other components as illustrated below.

NF0024

(1) Terminal (4) Coil

(2) Yoke core (5) Core
(3) Magnet (6) Cover

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

D As the crankshaft rotates, each tooth aligns with the crankshaft position sensor. At that time, the
magnetic flux in the sensor’s coil changes since the air gap between the sensor pickup and the
sprocket changes. This change in magnetic flux induces a voltage pulse in the sensor and the
pulse is transmitted to the ECM.

NF0398

(1) Crankshaft position sensor

(2) Crankshaft sprocket
(3) Crankshaft half rotation

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

F: CAMSHAFT POSITION SENSOR

D The camshaft position sensor is located on the left-hand camshaft support. It detects the com-
bustion cylinder at any given moment.
D The sensor generates a pulse when one of the bosses on the back of the left-hand camshaft
drive sprocket passes in front of the sensor. The ECM determines the camshaft angular position
by counting the number of pulses.
Internal construction and the basic operating principle of the camshaft position sensor are similar
to those of the crankshaft position sensor. Two bosses are provided on the sprocket as shown be-
low.

NF0335

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

G: KNOCK SENSOR
D The knock sensor is installed on the cylinder block, and senses knocking that occurs in the en-
gine.
D The sensor is a piezo-electric type which converts vibration resulting from knocking into electric
signals.
D In addition to a piezo-electric element, the sensor has a weight and case as its components.
If knocking occurs in the engine, the weight in the case moves causing the piezo-electric element
to generate a voltage.
D The knock sensor harness is connected to the bulkhead harness.

NF0391

(1) Nut (4) Housing

(2) Weight (5) Resistor
(3) Piezo-electric element

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

H: VEHICLE SPEED SENSOR

1. MT VEHICLES
D The vehicle speed sensor is mounted on the transmission.
D The vehicle speed sensor generates a 4-pulse signal for every rotation of the front differential
and send it to the ECM and the combination meter.

B2H2458C

(1) Combination meter

(2) ECM
(3) Vehicle speed sensor
(4) Transmission

FU-25

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SENSORS AND SWITCHES

Fuel Injection (Fuel System)

2. AT VEHICLES
D The vehicle speed sensor is mounted on the transmission.
D The vehicle speed sensor generates a 16-pulse signal for every rotation of the front differential
and send it to the transmission control module (TCM). The signal sent to the TCM is converted
there into a 4-pulse signal, and then sent to the ECM and the combination meter.

B2H2459B

(1) Combination meter

(2) ECM
(3) TCM
(4) Vehicle speed sensor
(5) Transmission

FU-26

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CONTROL SYSTEM
Fuel Injection (Fuel System)

5. Control System
A: GENERAL
The ECM receives signals from various sensors, switches, and other control modules. Using these
signals, it determines the engine operating conditions and if necessary, emits signals to one or
more systems to control them for optimum operation.
Major control items of the ECM are as follow:
D Fuel injection control
D Ignition system control
D Idle air control
D Fuel pump control
D Canister purge control*1
D Radiator fan control*2
D On-board diagnosis function
*1: Canister purge control is described under “EC (DOHC TURBO) – Emission Control (Aux. Emis-
sion Control Devices) Evaporative Emission Control System”.
*2: Radiator fan control is described under “CO – Cooling”.

FU-27

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CONTROL SYSTEM
Fuel Injection (Fuel System)

B: INPUT AND OUTPUT SIGNALS

Signal Unit Function
Pressure sensor Detects the amount of intake air (Measures the absolute pressure).
Mass air flow and intake air tempera-
Detects the temperature and amount of intake air.
ture sensor
Detects the amount of intake air (Measures the atmospheric pres-
Atmospheric pressure sensor
sure).
Throttle position sensor Detects the throttle valve position.
Detects the density of oxygen in exhaust gases at the upstream of
Front oxygen (A/F) sensor
the front catalytic converter.
Detects the density of oxygen in exhaust gases at the downstream
Rear oxygen sensor
of the rear catalytic converter.
Exhaust gas temperature sensor Detects the exhaust gas temperature.
Tumble generator valve position sen-
Detects the tumble generator valve position.
sor
Crankshaft position sensor Detects the crankshaft angular position.
Camshaft position sensor Detects the combustion cylinder.
Engine coolant temperature sensor Detects the engine coolant temperature.
I
Input
t signals
i l Knock sensor Detects engine knocking.
Vehicle speed sensor Detects the vehicle speed.
Ignition switch Detects operation of the ignition switch.
Starter switch Detects the condition of engine cranking.
Neutral position switch (MT) Detects that the gear is in neutral.
Torque control signal Controls engine torque.
Park/Neutral position switch (AT) Detects shift positions.
Heater circuit of front and rear oxy- Detects the abnormality in heater circuit of front and rear oxygen
gen sensor sensor.
A/C switch Detects ON-OFF operation of the A/C switch.
Fuel level sensor Detects the level of the fuel in the fuel tank.
Diagnostics of TCM Detects the self-diagnostics of the TCM.
Small light switch Detects ON-OFF operation of the small light switch.
Blower fan switch Detects ON-OFF operation of the blower fan switch.
Rear defogger switch Detects ON-OFF operation of the rear defogger switch.
Fuel Injector Activates an injector.
Ignition signal Turns the primary ignition current ON or OFF.
Fuel pump relay Controls the fuel pump.
A/C control relay Turns the A/C control relay ON or OFF.
Radiator fan control relay Turns the radiator fan control relay ON or OFF.
Adjusts the amount of air flowing through the bypass line in the
Output signals Idle air control solenoid valve
throttle body.
Tumble generator valve actuator Operates the tumble generator valve.
Wastegate control solenoid valve Controls supercharging pressure
Malfunction indicator lamp Indicates existence of abnormality.
Purge control solenoid valve Controls purge of evaporative gas absorbed by the canister.
Power supply Controls ON/OFF of the main power supply relay.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

C: FUEL INJECTION CONTROL

D The ECM receives signals from various sensors and based on them, it determines the amount
of fuel injected and the fuel injection timing. It performs the sequential fuel injection control over
the entire engine operating range except during start-up of the engine.
D The amount of fuel injected depends upon the length of time the injector stays open. The fuel
injection duration is determined according to varying operating condition of the engine. For the
purpose of achieving highly responsive and accurate fuel injection duration control, the ECM per-
forms a new feedback control that incorporates a learning feature as detailed later.
D The sequential fuel injection control is performed such that fuel is injected accurately at the time
when the maximum air intake efficiency can be achieved for each cylinder (i.e., fuel injection is
completed just before the intake valve begins to open).

1. FUEL INJECTION DURATION

Fuel injection duration is basically determined as indicated below:
D During engine start-up:
The duration defined below is used.
D Duration of fuel injection during engine start-up ..... Determined according to the engine cool-
ant temperature detected by the engine coolant temperature sensor.
D During normal operation:
The duration is determined as follows:
Basic duration of fuel injection x Correction factors + Voltage correction time
D Basic duration of fuel injection ..... The basic length of time fuel is injected. This is determined
by two factors – the amount of intake air detected by the manifold pressure sensor and the en-
gine speed monitored by the crankshaft position sensor.
D Correction factors ..... See the next section.
D Voltage correction time ..... This is added to compensate for the time lag before operation of
injector that results from variation in the battery voltage.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

2. CORRECTION FACTORS
The following factors are used to correct the basic duration of fuel injection in order to make the
air-fuel ratio meet the requirements of varying engine operating conditions:
D Air-fuel ratio feedback factor:
This factor is used to correct the basic duration of fuel injection in relation to the actual engine
speed. (See the next section for more detail.)
D Start increment factor:
This factor is used to increase the fuel injection duration only while the engine is being cranked
to improve its startability.
D Coolant-temperature-dependent increment factor:
This factor is used to increase the fuel injection duration depending on engine coolant temperature
signals to facilitate cold starting. The lower the coolant temperature, the greater the increment.
D After-start increment factor:
D This factor is used to increase the fuel injection duration for a certain period immediately after
start of the engine to stabilize engine operation.
D The increment depends on the coolant temperature at the start of the engine.
D Wide-open-throttle increment factor:
This factor is used to increase the fuel injection duration depending on the relationship between
the throttle position sensor signal and manifold pressure sensor signal.
D Acceleration increment factor:
This factor is used to increase the fuel injection duration to compensate for a time lag between air
flow measurement and fuel injection control for better engine response to driver’s pedal operation
during acceleration.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

3. AIR-FUEL RATIO FEEDBACK FACTOR

The ECM creates this factor utilizing the front oxygen sensor signal. When the signal voltage is low,
the air-fuel ratio is richer than the stoichiometric ratio. The ECM then makes the fuel injection dura-
tion shorter by modifying the factor. When the voltage is high showing that the mixture is lean, the
ECM modifies the factor to make the injection duration longer. In this way, the air-fuel ratio is main-
tained at a level close to the stoichiometric ratio at which the three-way catalyst acts most effective-
ly.

NF0030

(1) Front catalyst (4) Fuel injector

(2) Exhaust gas (5) Combustion chamber
(3) Front oxygen (A/F) sensor

4. LEARNING FEATURE
The air-fuel ratio feedback control includes a learning feature which contributes to more accurate
and responsive control.
D In the air-fuel ratio feedback control, the ECM calculates the necessary amount of correction
based on data from the oxygen sensor and adds the result to the basic duration (which is stored
in the ECM’s memory for each condition defined by the engine speed and various loads.)
D Without a learning feature, the ECM carries out the above-mentioned process every time. This
means that if the amount of necessary correction is large, the air-fuel ratio feedback control be-
comes less responsive and less accurate.
D The learning feature enables the ECM to store the amount of correction into memory and add
it to the basic fuel injection duration to create a new reference fuel injection duration. Using the
reference duration as the basic duration for the injection a few times later, the ECM can reduce
the amount of correction and thus make its feedback control more accurate and responsive to
changes in the air-fuel ratio due to difference in driving condition and sensor/actuator characteris-
tics that may result from unit-to-unit variation or aging over time.

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CONTROL SYSTEM
Fuel Injection (Fuel System)

D: IGNITION SYSTEM CONTROL

D The ECM determines operating condition of the engine based on signals from the pressure sen-
sor, engine coolant temperature sensor, intake air temperature sensor, crankshaft position sensor
and other sources. It then selects the ignition timing most appropriate for the condition thus deter-
mined from those stored in its memory and outputs at that timing a primary current OFF signal to
the ignitor to initiate ignition.
D This control uses a quick-to-response learning feature by which the data stored in the ECM
memory is processed in comparison with information from various sensors and switches.
D Thus, the ECM can always perform optimum ignition timing taking into account the output, fuel
consumption, exhaust gas, and other factors for every engine operating condition.
D Ignition control during start-up
Engine speed fluctuates during start of the engine, so the ECM cannot control the ignition timing.
During that period, the ignition timing is fixed at 10° BTDC by using the 10° signal from the crank-
shaft position sensor.

S2H2220A

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CONTROL SYSTEM
Fuel Injection (Fuel System)

D Ignition control under normal engine conditions

From the time between the 97° signal and 65° signal, the ECM measures the engine speed. Using
this engine speed data, it determines the dwell set timing and ignition timing so that they match
the engine condition.
D Ignition control during start
The engine speed fluctuates during a start, so the ECM cannot perform a speed-dependent con-
trol of the ignition timing. During engine start, therefore, the ECM performs an open-loop control
by fixing the ignition timing at 10° BTDC by using the 10° signal.

NF0392

(1) Cylinder number (TDC) (5) Ignition timing at normal condition

(2) Crank angle pulse (BTDC) (6) Burning cylinder
(3) Cam angle pulse (ATDC) (7) Dwell set
(4) Ignition timing at starting (8) Ignite

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CONTROL SYSTEM
Fuel Injection (Fuel System)

E: IDLE AIR CONTROL

D The ECM activates the idle air control solenoid valve to control the bypass air flowing through
the bypass passage in the throttle body depending on signals from the crankshaft position sensor,
engine coolant temperature sensor, pressure sensor and A/C switch so that the proper idle speed
for each engine load is achieved.
D The idle air control solenoid valve uses a duty-ratio-controlled solenoid which can continuously
vary the opening area of the rotary valve. As the ECM increases the duty ratio, opening of the rotary
valve increases so that the bypass air flow increases, and the engine idling speed becomes higher
as a result.
D The bypass air control is necessary for:
D Increasing idling speed when the air conditioning system and/or electrical loads are turned
on.
D Increasing idling speed during early stage of warm up period.
D Obtaining dashpot function when the throttle valve is quickly closed.
D Prevention of engine speed variation during idling.

S2H2221A

F: FUEL PUMP CONTROL

Using the signal from the crankshaft position sensor, the ECM controls operation of the fuel pump
by turning its relay ON or OFF. To improve safety, the fuel pump is stopped if the engine stalls with
the ignition switch ON.
Ignition switch ON Fuel pump relay Fuel pump
A certain period of time after ignition switch is turned ON ON Operates
While cranking the engine ON Operates
While engine is operating ON Operates
When engine stops OFF Does not operate

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ON-BOARD DIAGNOSIS SYSTEM

Fuel Injection (Fuel System)

6. On-board Diagnosis System

A: GENERAL
D The on-board diagnosis system detects and indicates a fault by generating a code correspond-
ing to each fault location. The malfunction indicator lamp (CHECK ENGINE light) on the combina-
tion meter indicates occurrence of a fault or abnormality.
D When the malfunction indicator lamp comes on as a result of detection of a fault by the ECM,
the corresponding diagnostic trouble code (DTC) and freeze frame engine condition are stored
in the ECM.
D On the OBD-II conformable car, it is necessary to connect the Subaru Select Monitor (SSM) or
General Scan Tool (GST) to the data link connector in order to check the DTC.
D The SSM and GST can read and erase DTCs. They can also read freeze frame data in addition
to other pieces of engine data.
D If there is a failure involving sensors which may affect drive control of the vehicle, the fail-safe
function ensures minimum level of driveability.

B: FAIL-SAFE FUNCTION
For a sensor or switch which has been judged faulty in the on-board diagnosis, the ECM, if ap-
propriate, generates an associated pseudo signal to keep the vehicle operational. (The control
becomes degraded.)

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ON-BOARD DIAGNOSIS SYSTEM

Fuel Injection (Fuel System)

MEMO

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EMISSION CONTROL
(AUX. EMISSION
CONTROL DEVICES) EC (SOHC)
Page
1. System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Schematic Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Crankcase Emission Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Three-way Catalyst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. A/F Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Ignition Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Evaporative Emission Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Vacuum Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
EC
SOHC

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SYSTEM OVERVIEW
Emission Control (Aux. Emission Control Devices)

1. System Overview
There are three emission control systems which are as follows:
D Crankcase emission control system
D Exhaust emission control system
D Three-way catalyst system
D Air/fuel (A/F) control system
D Ignition control system
D Evaporative emission control system
Item Main components Function
Crankcase emission control Positive crankcase Draws blow-by gas into intake manifold from crankcase and burns it
system ventilation (PCV) together with air-fuel mixture. Amount of blow-by gas to be drawn in
valve is controlled by intake manifold pressure.
Exhaust Catalyst Front Three-way catalyst Oxidizes HC and CO contained in exhaust gases as well as reducing
emission system NOx
NOx.
Rear
control
system A/F control Engine control mod- Receives input signals from various sensors, compares signals with
system ule (ECM) stored data, and emits a signal for optimal control of air-fuel mixture
ratio.
Front oxygen (A/F) Detects quantity of oxygen contained exhaust gases.
sensor
Rear oxygen sensor Detects density of oxygen contained exhaust gases.
Throttle position Detects throttle position.
sensor
Intake air tempera- Detects absolute pressure of intake manifold.
ture and pressure
sensor Detects intake air temperature of intake manifold.

Ignition control ECM Receives various signals, compares signals with basic data stored in
system memory, and emits a signal for optimal control of ignition timing.
Crankshaft position Detects engine speed (Revolution).
sensor
Camshaft position Detects reference signal for combustion cylinder discrimination.
sensor
Engine coolant tem- Detects coolant temperature.
perature sensor
Knock sensor Detects engine knocking.
Evaporative emission control Canister Absorbs evaporative gas which occurs in fuel tank when engine
system stops, and releases it to combustion chambers for a complete burn
when engine is started. This prevents HC from being discharged into
atmosphere.
Purge control Receives a signal from ECM and controls purge of evaporative gas
solenoid valve absorbed by canister.

EC-2

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SYSTEM OVERVIEW
Emission Control (Aux. Emission Control Devices)

MEMO

EC-3

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SCHEMATIC DIAGRAMS
Emission Control (Aux. Emission Control Devices)

2. Schematic Diagrams

NF0358

EC-4

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見開き右

SCHEMATIC DIAGRAMS
Emission Control (Aux. Emission Control Devices)

(1) Engine control module (ECM) (21) Radiator fan

(2) Ignition coil and ignitor assembly (22) Radiator fan relay
(3) Crankshaft position sensor (23) Atmospheric pressure sensor
(4) Camshaft position sensor (24) Knock sensor
(5) Throttle position sensor (25) Front oxygen (A/F) sensor
(6) Fuel injectors (26) Rear oxygen sensor
(7) Pressure regulator (27) Air assist injector solenoid valve
(8) Engine coolant temperature sensor (28) A/C compressor
(9) Intake air temperature and pressure sensor (29) Inhibitor switch
(10) Idle air control solenoid valve (30) Neutral position switch
(11) Purge control solenoid valve (31) CHECK ENGINE malfunction indicator lamp (MIL)
(12) Fuel pump (32) Tachometer
(13) PCV valve (33) A/C relay
(14) Air cleaner (34) A/C control module
(15) Canister (35) Ignition switch
(16) Main relay (36) Transmission control module (TCM)
(17) Fuel pump relay (37) Vehicle speed sensor
(18) Fuel filter (38) Data link connector
(19) Front catalytic converter (39) Fuel cut valve
(20) Rear catalytic converter (40) Two-way valve

EC-5

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CRANKCASE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

3. Crankcase Emission Control System

D The positive crankcase ventilation (PCV) system prevents air pollution which will be caused by
blow-by gas being emitted from the crankcase.
The system consists of a sealed oil filler cap, rocker covers with fresh air inlet, connecting hoses,
a PCV valve and an air intake duct.
D In a part-throttle condition, the blow-by gas in the crankcase flows into the intake manifold
through the connecting hose of crankcase and PCV valve by the strong vacuum created in the
intake manifold. Under this condition, fresh air is introduced into the crankcase through the con-
necting hose of the rocker cover.
D In a wide-open-throttle condition, a part of blow-by gas flows into the air intake duct through the
connecting hose and is drawn into the throttle chamber, because under this is condition, the intake
manifold vacuum is not strong enough to introduce through the PCV valve all blow-by gases that
increase in the amount with engine speed.

NF0354

EC-6

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THREE-WAY CATALYST
Emission Control (Aux. Emission Control Devices)

4. Three-way Catalyst
D The basic material of three-way catalyst is platinum (Pt), rhodium (Rh) and palladium (Pd), and
a thin coat of their mixture is applied onto honeycomb or porous ceramics of an oval shape (carri-
er). To avoid damaging the catalyst, only unleaded gasoline should be used.
D The catalyst reduces HC, CO and NOx in exhaust gases through chemical reactions (oxidation
and reduction). These harmful components are reduced most efficiently when their concentra-
tions are in a certain balance. These concentrations vary with the air-fuel ratio. The ideal air-fuel
ratio for reduction of these components is the stoichiometric ratio.
D Therefore, the air-fuel ratio needs to be controlled to around the stoichiometric ratio to purify the
exhaust gases most efficiently.

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A/F CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

5. A/F Control System

D The air/fuel (A/F) control system makes a correction to the basic fuel injection duration in accor-
dance with the signal from the front oxygen sensor so that the stoichiometric ratio is maintained,
thus ensuring most effective exhaust gas purification by the three-way catalyst. Different basic fuel
injection durations are preset for various engine speeds and loads, as well as the amount of intake
air.
D This system also has a “learning” control function which stores the corrected data in relation to
the basic fuel injection in the memory map. This allows an appropriate air-fuel ratio correction to
be added automatically in quick response to any situation that requires such an effect. Thus, the
air-fuel ratio is optimally maintained under various conditions while purifying exhaust gases most
effectively, improving driving performance and compensating for changes in sensors’ perfor-
mance over time.

EC-8

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IGNITION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

6. Ignition Control System

D The ignition system is controlled by the ECM.
The ECM monitors the operating condition of the engine using the signals from the sensors and
switches shown below and determines the ignition timing most appropriate for each engine oper-
ating condition. Then it sends a signal to the ignitor, commanding generation of a spark at that
timing.
D The ECM uses a preprogrammed map for a “closed-loop” control which provides its ignition tim-
ing control with excellent transient characteristics, i.e., highly responsive ignition timing control.

B2H3536D

(1) Battery (6) Intake air temperature and pressure sensor

(2) Ignition switch (7) Engine coolant temperature sensor
(3) ECM (8) Spark plug
(4) Camshaft position sensor (9) Ignition coil and ignitor assembly
(5) Knock sensor (10) Crankshaft position sensor

EC-9

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

7. Evaporative Emission Control System

A: GENERAL
D The evaporative emission control system prevents fuel vapors from escaping into atmosphere.
This system includes a canister, purge control solenoid valve, fuel cut valve, and the lines connect-
ing them.
D Fuel vapors in the fuel tank is introduced into the canister through the evaporation line, and are
absorbed by activated carbon in it. The fuel cut valve is also incorporated in the fuel tank line.
D The purge control solenoid valve is controlled optimally by the ECM according to the engine
condition.

S2H2171A

(1) Intake manifold (5) Canister

(2) Throttle body (6) Fuel tank
(3) Purge control solenoid valve (7) Fuel cut valve
(4) Engine control module (ECM) (8) Two-way valve

EC-10

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

B: FUEL CUT VALVE

The fuel cut valve is built onto the evaporation pipe of the fuel tank cap. The rising level of the fuel
in the fuel tank causes the float to move up and close the cap hole so that no fuel can enter the
evaporation line.

B2H3342C

(1) Float A: To canister

B: Fuel level inside tank
C: Valve open
D: Valve closed

EC-11

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

C: FUEL TANK CAP

The fuel tank cap has a relief valve which prevents development of vacuum in the fuel tank in the
event of a problem with the fuel vapor line.
When there is no problem with the fuel vapor line, the filler pipe is sealed at the portion (A) and
by the seal pressed against the filler pipe end. If vacuum develops in the fuel tank, the atmospheric
pressure forces the spring down to open the valve; consequently outside air flows into the fuel tank,
thus controlling the inside pressure.

B2H0395C

(1) Seal
(2) Spring
(3) Valve

EC-12

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

D: CANISTER
The charcoal filled in the canister temporarily stores fuel vapors. When the purge control solenoid
valve is opened by a signal from the ECM, the external fresh air entering the canister carries the
fuel vapors into the collector chamber.

B2H4209B

(1) Filter A: To purge control solenoid valve

(2) Activated charcoal B: From fuel tank
(3) Spring C: Air

E: PURGE CONTROL SOLENOID VALVE

The purge control solenoid valve is on the evaporation line between the canister and intake man-
ifold. It is installed at the underside of intake manifold.

NF0410

A: To canister
B: To intake manifold

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

F: TWO-WAY VALVE
The two-way valve is located in the evaporation line between the fuel tank and the canister.
When the tank inside pressure becomes higher than the atmospheric pressure, the valve is
opened allowing fuel vapors to be introduced into the canister.
On the other hand, when the tank inside pressure becomes lower than the atmospheric pressure,
external air is taken from the canister.

B2H4138B

(1) Valve A: Atmospheric pressure

B: To canister
C: From fuel tank

EC-14

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VACUUM CONNECTIONS
Emission Control (Aux. Emission Control Devices)

8. Vacuum Connections
The hose and pipe connections of the intake manifold, throttle body and other related parts are
as shown in the illustration.

NF0359

(1) Pressure regulator

(2) Throttle body
(3) Purge control solenoid valve
(4) Air assist injector solenoid valve

EC-15

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VACUUM CONNECTIONS
Emission Control (Aux. Emission Control Devices)

MEMO

EC-16

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EMISSION CONTROL
SOHC
(AUX. EMISSION w/o
CONTROL DEVICES) EC OBD
Page
1. System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Schematic Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Crankcase Emission Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Three-way Catalyst (with Catalyst Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. A/F Control System (with Catalyst Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Ignition Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Evaporative Emission Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Vacuum Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

EC
SOHC
–OBD

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SYSTEM OVERVIEW
Emission Control (Aux. Emission Control Devices)

1. System Overview
There are three emission control systems which are as follows:
D Crankcase emission control system
D Exhaust emission control system
D Three-way catalyst system
D Air/fuel (A/F) control system
D Ignition control system
D Evaporative emission control system

Item Main components Function

Crankcase emission control sys- Positive crankcase Draws blow-by gas into intake manifold from crankcase and burns it
tem ventilation (PCV) together with air-fuel mixture. Amount of blow-by gas to be drawn in
valve is controlled by intake manifold pressure.
Exhaust Catalyst Front Three-way catalyst Oxidizes HC and CO contained in exhaust gases as well as reduc-
emission system*1 ing NOx.
NOx
Rear*2
sys-
control sys
tem A/F control Engine control mod- Receives input signals from various sensors, compares signals with
system ule (ECM) stored data, and emits a signal for optimal control of air-fuel mixture
ratio.
Oxygen sensor*1 Detects density of oxygen contained exhaust gases.
Pressure sensor Detects absolute pressure of intake manifold.
Intake air tempera- Detects intake air temperature of intake manifold.
ture
Throttle position Detects throttle position.
sensor
Ignition control ECM Receives various signals, compares signals with basic data stored
system in memory, and emits a signal for optimal control of ignition timing.
Crankshaft position Detects engine speed (Revolution).
sensor
Engine coolant tem- Detects coolant temperature.
perature sensor
Knock sensor Detects engine knocking.
Evaporative emission control Canister Absorbs evaporative gas which occurs in fuel tank when engine
system stops, and releases it to combustion chambers for a complete burn
when engine is started. This prevents HC from being discharged
into atmosphere.
Purge control Receives a signal from ECM and controls purge of evaporative gas
solenoid valve absorbed by canister.

*1: With catalyst

*2: Except Australia spec. vehicles

EC-2

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SYSTEM OVERVIEW
Emission Control (Aux. Emission Control Devices)

MEMO

EC-3

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SCHEMATIC DIAGRAMS
Emission Control (Aux. Emission Control Devices)

2. Schematic Diagrams

S2H1108A

EC-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD02
見開き右

SCHEMATIC DIAGRAMS
Emission Control (Aux. Emission Control Devices)

(1) Engine control module (ECM) (22) Knock sensor

(2) Ignition coil and ignitor assembly (23) A/C compressor
(3) Crankshaft position sensor (24) Inhibitor switch (AT vehicle only)
(4) Fuel cut valve (25) Neutral position switch (MT vehicle only)
(5) Throttle position sensor (26) CHECK ENGINE malfunction indicator lamp (MIL)
(6) Fuel injectors (27) Tachometer
(7) Pressure regulator (28) A/C relay
(8) Engine coolant temperature sensor (29) A/C control module
(9) Pressure sensor (30) Ignition switch
(10) Intake air temperature sensor (31) Vehicle speed sensor
(11) Idle air control solenoid valve (32) Data link connector
(12) Purge control solenoid valve (33) Transmission control module (TCM) (AT vehicle only)
(13) Fuel pump (34) Power steering fluid pressure switch
(14) PCV valve (35) Two-way valve
(15) Air cleaner (36) Oxygen sensor *1
(16) Canister (37) Front catalytic converter *1
(17) Main relay (38) Rear catalytic converter *1, *2
(18) Fuel pump relay (39) CO resister (Without catalyst)
(19) Fuel filter
(20) Radiator fan *1: With catalyst
(21) Radiator fan relay *2: Except Australia spec. vehicles

EC-5

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD03

CRANKCASE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

3. Crankcase Emission Control System

D The positive crankcase ventilation (PCV) system prevents air pollution which will be caused by
blow-by gas being emitted from the crankcase.
The system consists of a sealed oil filler cap, rocker covers with fresh air inlet, connecting hoses,
a PCV valve and an air intake duct.
D In a part-throttle condition, the blow-by gas in the crankcase flows into the intake manifold
through the connecting hose of crankcase and PCV valve by the strong vacuum created in the
intake manifold. Under this condition, fresh air is introduced into the crankcase through the con-
necting hose of the rocker cover.
D In a wide-open-throttle condition, a part of blow-by gas flows into the air intake duct through the
connecting hose and is drawn into the throttle chamber, because under this is condition, the intake
manifold vacuum is not strong enough to introduce through the PCV valve all blow-by gases that
increase in the amount with engine speed.

Part-throttle condition

Crankcase

Wide-open-throttle condition

Crankcase

B2H3534C

EC-6

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THREE-WAY CATALYST (WITH CATALYST MODEL)

Emission Control (Aux. Emission Control Devices)

4. Three-way Catalyst (with Catalyst Model)

D The basic material of three-way catalyst is platinum (Pt), rhodium (Rh) and palladium (Pd), and
a thin coat of their mixture is applied onto honeycomb or porous ceramics of an oval shape (carri-
er). To avoid damaging the catalyst, only unleaded gasoline should be used.
D The catalyst reduces HC, CO and NOx in exhaust gases through chemical reactions (oxidation
and reduction). These harmful components are reduced most efficiently when their concentra-
tions are in a certain balance. These concentrations vary with the air-fuel ratio. The ideal air-fuel
ratio for reduction of these components is the stoichiometric ratio.
D Therefore, the air-fuel ratio needs to be controlled to around the stoichiometric ratio to purify the
exhaust gases most efficiently.

EC-7

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD05

A/F CONTROL SYSTEM (WITH CATALYST MODEL)

Emission Control (Aux. Emission Control Devices)

5. A/F Control System (with Catalyst Model)

D The air/fuel (A/F) control system makes a correction to the basic fuel injection duration in accor-
dance with the signal from the oxygen sensor so that the stoichiometric ratio is maintained, thus
ensuring most effective exhaust gas purification by the three-way catalyst. Different basic fuel in-
jection durations are preset for various engine speeds and loads, as well as the amount of intake
air.
D This system also has a “learning” control function which stores the corrected data in relation to
the basic fuel injection in the memory map. This allows an appropriate air-fuel ratio correction to
be added automatically in quick response to any situation that requires such an effect. Thus, the
air-fuel ratio is optimally maintained under various conditions while purifying exhaust gases most
effectively, improving driving performance and compensating for changes in sensors’ perfor-
mance over time.

EC-8

136
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD06

IGNITION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

6. Ignition Control System

D The ignition system is controlled by the ECM.
The ECM monitors the operating condition of the engine using the signals from the sensors and
switches shown below and determines the ignition timing most appropriate for each engine oper-
ating condition. Then it sends a signal to the ignitor, commanding generation of a spark at that
timing.
D The ECM uses a preprogrammed map for a “closed-loop” control which provides its ignition tim-
ing control with excellent transient characteristics, i.e., highly responsive ignition timing control.

S2H1731B

(1) Battery (7) Spark plug

(2) Ignition switch (8) Pressure sensor
(3) ECM (9) Air cleaner case
(4) Crankshaft position sensor (10) Intake air temperature sensor
(5) Ignition coil and ignitor assembly (11) Engine coolant temperature sensor
(6) Knock sensor

EC-9

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

7. Evaporative Emission Control System

A: GENERAL
D The evaporative emission control system prevents fuel vapors from escaping into atmosphere.
This system includes a canister, purge control solenoid valve, fuel cut valve, and the lines connect-
ing them.
D Fuel vapors in the fuel tank is introduced into the canister through the evaporation line, and are
absorbed by activated carbon in it. The fuel cut valve is also incorporated in the fuel tank line.
D The purge control solenoid valve is controlled optimally by the ECM according to the engine
condition.

S2H2262A

(1) ECM (5) Fuel tank

(2) Purge control solenoid valve (6) Throttle body
(3) Canister (7) Fuel cut valve
(4) Two-way valve

EC-10

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

B: FUEL CUT VALVE

The fuel cut valve is built onto the evaporation pipe of the fuel tank cap. The rising level of the fuel
in the fuel tank causes the float to move up and close the cap hole so that no fuel can enter the
evaporation line.

H2H3222B

(1) Float
A: To canister

EC-11

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

C: FUEL TANK CAP

The fuel tank cap has a relief valve which prevents development of vacuum in the fuel tank in the
event of a problem with the fuel vapor line.
When there is no problem with the fuel vapor line, the filler pipe is sealed at the portion (A) and
by the seal pressed against the filler pipe end. If vacuum develops in the fuel tank, the atmospheric
pressure forces the spring down to open the valve; consequently outside air flows into the fuel tank,
thus controlling the inside pressure.
1. UNLEADED GASOLINE SPEC. VEHICLES

B2H0395C

(1) Seal
(2) Spring
(3) Valve

2. LEADED GASOLINE SPEC. VEHICLES

S2H0747A

(1) Seal
(2) Spring
(3) Valve

EC-12

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD07

EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

D: CANISTER
The charcoal filled in the canister temporarily stores fuel vapors. When the purge control solenoid
valve is opened by a signal from the ECM, the external fresh air entering the canister carries the
fuel vapors into the collector chamber.

S2H2021A

(1) Filter A: From fuel tank

(2) Charcoal B: To purge control solenoid valve
C: Air

E: PURGE CONTROL SOLENOID VALVE

The purge control solenoid valve is on the evaporation line between the canister and intake man-
ifold. It is installed at the underside of intake manifold.

NF0410

A: To canister
B: To intake manifold

EC-13

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

F: TWO-WAY VALVE
D The two-way valve is located in the evaporation line between the fuel tank and canister. When
fuel vapor pressure in the fuel tank exceeds the specified value, the valve is pressurized to push
the spring. This lifts the valve away from its seat so that evaporative gas is discharged to the canis-
ter.
D When fuel vapor pressure in the fuel tank drops to the specified level, the valve is pressed
against its seat. However, air which enters from the inlet port of the canister is introduced into the
fuel tank through the pin hole located at the end of the valve.

S2H2023A

(1) Body A: To canister

(2) Seat B: From fuel tank
(3) Cap
(4) Pin hole
(5) Valve
(6) Spring

EC-14

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD08

VACUUM CONNECTIONS
Emission Control (Aux. Emission Control Devices)

8. Vacuum Connections
The hose and pipe connections of the intake manifold, throttle body and other related parts are
as shown in the illustration.

S2H2263A

(1) Pressure regulator A: HOSE

(2) Throttle body B: PIPE
(3) Purge control solenoid valve C: FRONT OF VEHICLE

EC-15

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_S-OBD08

VACUUM CONNECTIONS
Emission Control (Aux. Emission Control Devices)

MEMO

EC-16

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DOHC
EC TURBO
Page
1. System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Schematic Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Crankcase Emission Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Three-way Catalyst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. A/F Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Ignition Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Evaporative Emission Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Vacuum Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

EC
DOHC

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D01

SYSTEM OVERVIEW
Emission Control (Aux. Emission Control Devices)

1. System Overview
There are three emission control systems which are as follows:
D Crankcase emission control system
D Exhaust emission control system
D Three-way catalyst system
D Air/fuel (A/F) control system
D Ignition control system
D Evaporative emission control system
Item Main components Function
Crankcase emission control Positive crankcase Draws blow-by gas into intake manifold from crankcase and burns it
system ventilation (PCV) together with air-fuel mixture. Amount of blow-by gas to be drawn in
valve is controlled by intake manifold pressure.
Exhaust Catalyst Pre Three-way catalyst Oxidizes HC and CO contained in exhaust gases as well as reducing
emission system NOx
NOx.
Front
control
system Rear
A/F control Engine control mod- Receives input signals from various sensors, compares signals with
system ule (ECM) stored data, and emits a signal for optimal control of air-fuel mixture
ratio.
Front oxygen (A/F) Detects quantity of oxygen contained exhaust gases.
sensor
Rear oxygen sensor Detects density of oxygen contained exhaust gases.
Throttle position Detects throttle position.
sensor
Mass air flow sensor Detects amount of intake air.
and intake air tem-
perature sensor Detects intake air temperature of air cleaner case.

Ignition control ECM Receives various signals, compares signals with basic data stored in
system memory, and emits a signal for optimal control of ignition timing.
Crankshaft position Detects engine speed (Revolution).
sensor
Camshaft position Detects reference signal for combustion cylinder discrimination.
sensor
Engine coolant tem- Detects coolant temperature.
perature sensor
Knock sensor Detects engine knocking.
Evaporative emission control Canister Absorbs evaporative gas which occurs in fuel tank when engine
system stops, and releases it to combustion chambers for a complete burn
when engine is started. This prevents HC from being discharged into
atmosphere.
Purge control Receives a signal from ECM and controls purge of evaporative gas
solenoid valve absorbed by canister.

EC-2

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SYSTEM OVERVIEW
Emission Control (Aux. Emission Control Devices)

MEMO

EC-3

147
見開き左W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D02

SCHEMATIC DIAGRAMS
Emission Control (Aux. Emission Control Devices)

2. Schematic Diagrams

S2H2223A

EC-4

148
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D02
見開き右

SCHEMATIC DIAGRAMS
Emission Control (Aux. Emission Control Devices)

(1) Engine control module (ECM) (25) Rear oxygen sensor

(2) Ignition coil and ignitor assembly (26) Rear catalytic converter
(3) Crankshaft position sensor (27) Radiator fan
(4) Camshaft position sensor (28) Radiator fan relay
(5) Throttle position sensor (29) Knock sensor
(6) Fuel injectors (30) A/C compressor
(7) Pressure regulator (31) Neutral position switch
(8) Engine coolant temperature sensor (32) CHECK ENGINE malfunction indicator lamp (MIL)
(9) Pressure sensor (33) Tachometer
(10) Idle air control solenoid valve (34) A/C relay
(11) Purge control solenoid valve (35) A/C control module
(12) Fuel pump (36) Ignition switch
(13) Mass air flow and intake air temperature sensor (37) Vehicle speed sensor
(14) Air cleaner (38) Data link connector
(15) Canister (39) Fuel cut valve
(16) Main relay (40) Wastegate control solenoid valve
(17) Fuel pump relay (41) Wastegate controller
(18) Fuel filter (42) Purge valve
(19) Inhibitor switch (AT vehicle only) (43) Air bypass valve
(20) Two-way valve (44) Turbocharger
(21) Front catalytic converter (45) Intercooler
(22) Exhaust temperature sensor (46) Tumble generator valve position sensor
(23) Precatalytic converter (47) Tumble generator valve actuator
(24) Front oxygen (A/F) sensor (48) Transmission control module (TCM) (AT vehicle only)

EC-5

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D03

CRANKCASE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

3. Crankcase Emission Control System

D The positive crankcase ventilation (PCV) system prevents air pollution which will be caused by
blow-by gas being emitted from the crankcase.
The system consists of a sealed oil filler cap, rocker covers with fresh air inlet, connecting hoses,
a PCV valve and an air intake duct.
D In a part-throttle condition, the blow-by gas in the crankcase flows into the intake manifold
through the connecting hose of crankcase and PCV valve by the strong vacuum created in the
intake manifold. Under this condition, fresh air is introduced into the crankcase through the con-
necting hose of the rocker cover.
D In a wide-open-throttle condition, a part of blow-by gas flows into the air intake duct through the
connecting hose and is drawn into the throttle chamber, because under this is condition, the intake
manifold vacuum is not strong enough to introduce through the PCV valve all blow-by gases that
increase in the amount with engine speed.

NF0307

(1) Air intake duct (5) Case A: To intake manifold

(2) PCV valve (6) Valve
(3) Intake manifold (7) Spring
(4) Crankcase (8) PCV valve

EC-6

150
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D04

THREE-WAY CATALYST
Emission Control (Aux. Emission Control Devices)

4. Three-way Catalyst
D The basic material of three-way catalyst is platinum (Pt), rhodium (Rh) and palladium (Pd), and
a thin coat of their mixture is applied onto honeycomb or porous ceramics of an oval shape (carri-
er). To avoid damaging the catalyst, only unleaded gasoline should be used.
D The catalyst reduces HC, CO and NOx in exhaust gases through chemical reactions (oxidation
and reduction). These harmful components are reduced most efficiently when their concentra-
tions are in a certain balance. These concentrations vary with the air-fuel ratio. The ideal air-fuel
ratio for reduction of these components is the stoichiometric ratio.
D Therefore, the air-fuel ratio needs to be controlled to around the stoichiometric ratio to purify the
exhaust gases most efficiently.

EC-7

151
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D05

A/F CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

5. A/F Control System

D The air/fuel (A/F) control system makes a correction to the basic fuel injection duration in accor-
dance with the signal from the front oxygen sensor so that the stoichiometric ratio is maintained,
thus ensuring most effective exhaust gas purification by the three-way catalyst. Different basic fuel
injection durations are preset for various engine speeds and loads, as well as the amount of intake
air.
D This system also has a “learning” control function which stores the corrected data in relation to
the basic fuel injection in the memory map. This allows an appropriate air-fuel ratio correction to
be added automatically in quick response to any situation that requires such an effect. Thus, the
air-fuel ratio is optimally maintained under various conditions while purifying exhaust gases most
effectively, improving driving performance and compensating for changes in sensors’ perfor-
mance over time.

EC-8

152
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D06

IGNITION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

6. Ignition Control System

D The ignition system is controlled by the ECM.
The ECM monitors the operating condition of the engine using the signals from the sensors and
switches shown below and determines the ignition timing most appropriate for each engine oper-
ating condition. Then it sends a signal to the ignitor, commanding generation of a spark at that
timing.
D The ECM uses a preprogrammed map for a “closed-loop” control which provides its ignition tim-
ing control with excellent transient characteristics, i.e., highly responsive ignition timing control.

NF0308

(1) Battery (6) Ignition coil and ignitor assembly

(2) Ignition switch (7) Knock sensor
(3) ECM (8) Mass air flow and intake air temperature sensor
(4) Camshaft position sensor (9) Engine coolant temperature sensor
(5) Crankshaft position sensor

EC-9

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D07

EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

7. Evaporative Emission Control System

A: GENERAL
D The evaporative emission control system prevents fuel vapors from escaping into atmosphere.
This system includes a canister, purge control solenoid valve, fuel cut valve, and the lines connect-
ing them.
D Fuel vapors in the fuel tank is introduced into the canister through the evaporation line, and are
absorbed by activated carbon in it. The fuel cut valve is also incorporated in the fuel tank line.
D The purge control solenoid valve is controlled optimally by the ECM according to the engine
condition.

NF0309

(1) Intake manifold (6) Two-way valve

(2) Throttle body (7) Purge valve
(3) Purge control solenoid valve (8) Fuel cut valve
(4) Engine control module (ECM) (9) Fuel tank
(5) Canister

EC-10

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EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

B: FUEL CUT VALVE

The fuel cut valve is built onto the evaporation pipe of the fuel tank cap. The rising level of the fuel
in the fuel tank causes the float to move up and close the cap hole so that no fuel can enter the
evaporation line.

B2H3342C

(1) Float A: To canister

B: Fuel level inside tank
C: Valve open
D: Valve closed

EC-11

155
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D07

EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

C: FUEL TANK CAP

The fuel tank cap has a relief valve which prevents development of vacuum in the fuel tank in the
event of a problem with the fuel vapor line.
When there is no problem with the fuel vapor line, the filler pipe is sealed at the portion (A) and
by the seal pressed against the filler pipe end. If vacuum develops in the fuel tank, the atmospheric
pressure forces the spring down to open the valve; consequently outside air flows into the fuel tank,
thus controlling the inside pressure.

B2H0395C

(1) Seal
(2) Spring
(3) Valve

EC-12

156
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D07

EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

D: CANISTER
The charcoal filled in the canister temporarily stores fuel vapors. When the purge control solenoid
valve is opened by a signal from the ECM, the external fresh air entering the canister carries the
fuel vapors into the collector chamber.

B2H4209B

(1) Filter A: To purge control solenoid valve

(2) Activated charcoal B: From fuel tank
(3) Spring C: Air

EC-13

157
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D07

EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

E: PURGE CONTROL SOLENOID VALVE

The purge control solenoid valve is on the evaporation line between the canister and intake man-
ifold. It is installed at the underside of intake manifold.

NF0386

A: To canister
B: To intake manifold

EC-14

158
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D07

EVAPORATIVE EMISSION CONTROL SYSTEM

Emission Control (Aux. Emission Control Devices)

F: TWO-WAY VALVE
The two-way valve is located in the evaporation line between the fuel tank and the canister.
When the tank inside pressure becomes higher than the atmospheric pressure, the valve is
opened allowing fuel vapors to be introduced into the canister.
On the other hand, when the tank inside pressure becomes lower than the atmospheric pressure,
external air is taken from the canister.

B2H4138B

(1) Valve A: Atmospheric pressure

B: To canister
C: From fuel tank

EC-15

159
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EC_D08

VACUUM CONNECTIONS
Emission Control (Aux. Emission Control Devices)

8. Vacuum Connections
The hose and pipe connections of the intake manifold, throttle body and other related parts are
as shown in the illustration.

NF0315

(1) Pressure regulator A: IN

(2) Purge control solenoid valve B: OUT
(3) Hose C: To canister
(4) Pipe D: Front of vehicle

EC-16

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INTAKE (INDUCTION) IN (SOHC)

Page
1. General ................................................................................2

IN
SOHC

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GENERAL
Intake (Induction)

1. General
The intake system consists of an air intake duct, a resonator chamber, and an air cleaner housed
in its case. The resonator, located upstream of the air cleaner, effectively reduces the intake noise
level.

S2H2219A

(1) Air intake duct A: Fresh air

(2) Resonator chamber B: To throttle body
(3) Air cleaner case
(4) Air cleaner element

IN-2

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DOHC
INTAKE (INDUCTION) IN TURBO
Page
1. Intake System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Turbocharger System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

IN
DOHC

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. IN_D01

INTAKE SYSTEM
Intake (Induction)

1. Intake System
A: GENERAL
The intake system consists of an air intake duct, a resonator chamber, and an air cleaner housed
in its case. The resonator, located upstream of the air cleaner, effectively reduces the intake noise
level.

S2H2224A

(1) Air intake duct A: Fresh air

(2) Resonator chamber B: To turbocharger
(3) Air cleaner case
(4) Mass air flow and intake air temperature sensor
(5) Intake boot
(6) Intake duct

IN-2

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TURBOCHARGER SYSTEM
Intake (Induction)

2. Turbocharger System
A: GENERAL
D The turbocharger system consists of a water-cooled turbocharger, air-cooled intercooler, waste-
gate control solenoid valve, etc.
D The outlet side turbine, rotated by exhaust gas pressure, rotates the inlet side turbine. As a re-
sult, the inlet side turbine compresses the intake air before it is delivered to the intake manifold.
D The intake air is heated when it passes through the turbocharger unit. The air is cooled as it
passes through the intercooler.
D This turbocharger system controls the supercharging pressure according to changes in the at-
mospheric pressure. Even at a high altitude, therefore, the system offers stable performance with-
out being affected by variations in atmospheric pressure.

NF0343

(1) Pressure sensor (9) Wastegate controller

(2) Crankshaft position sensor (10) Wastegate control solenoid valve
(3) Camshaft position sensor (11) Air bypass valve
(4) Throttle position sensor (12) Intercooler
(5) Engine coolant temperature sensor (13) Throttle body
(6) Mass air flow and intake air temperature sensor (14) Intake manifold
(7) Wastegate valve (15) ECM
(8) Turbocharger unit

IN-3

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TURBOCHARGER SYSTEM
Intake (Induction)

B: TURBOCHARGER UNIT
The turbocharger is water-cooled. It utilizes a wastegate valve to adjust its supercharging pres-
sure to an optimum level. The turbine is housed in a lightweight, thin-wall, heat-resistant casting.
The compressor housing is made of thin-wall, aluminum alloy casting. The shaft for turbine and
compressor is supported by a full-floating metal bearing system.

NF0344

(1) Wastegate controller A: Lubricating oil outlet E: Lubricating oil inlet

(2) Compressor housing B: Exhaust gas outlet F: Air inlet
(3) Turbine housing C: Air outlet G: Wastegate valve operating pressure
D: Engine coolant inlet

IN-4

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TURBOCHARGER SYSTEM
Intake (Induction)

C: LUBRICATION OF TURBOCHARGER
The turbocharger is lubricated by engine oil branched out from the oil pump. To cope with very
high speed of the turbocharger turbine and the compressor shaft which may reach a maximum
of several hundred thousands of rpm, full-floating type bearings are used which can form ade-
quate oil films on their inside and outside during running.
Further the oil supplied to the turbocharger also plays a role of cooling the turbine so that heat from
exhaust gas does not transmitted to the bearings.

NF0345

(1) Compressor housing (3) Turbine housing

(2) Turbine wheel (4) Compressor impeller

D: COOLING OF TURBOCHARGER
The turbocharger unit is cooled by engine coolant, which enhances the reliability and durability
of the unit. The engine coolant from the coolant drain hose located under the cylinder head is led
by a pipe to the coolant passage provided in the turbocharger bearing housing. After cooling the
bearing housing, the engine coolant is led into the coolant filler tank through a pipe.

IN-5

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TURBOCHARGER SYSTEM
Intake (Induction)

E: WASTEGATE CONTROL SOLENOID VALVE

The wastegate control solenoid valve switches the intake air pressure passages to the wastegate
controller in response to signals from the ECM. When the solenoid valve is closed, the intake air
pressure upstream of the turbocharger unit is applied to the wastegate controller. When the sole-
noid valve is opened, the intake air pressure downstream of the turbocharger unit (supercharged
air pressure) is applied to the wastegate controller.

NF0346

(1) Coil

IN-6

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TURBOCHARGER SYSTEM
Intake (Induction)

F: REGULATION OF SUPERCHARGING PRESSURE

1. BASIC FUNCTION OF THE WASTEGATE VALVE
When the engine speed increases as the throttle valve opens, the amount of exhaust gas in-
creases. This increases the speed of the turbine (approx. 20,000 to 150,000 rpm), the supercharg-
ing pressure and the engine output.
If the resultant supercharging pressure is extremely high, however, it may cause knocking and an
excessively high thermal load on such engine components as pistons. In the worst case, the en-
gine may be damaged or broken. To prevent this, the wastegate valve and its controller are pro-
vided. By sensing the supercharging pressure, the wastegate valve controller controls the opera-
tion of the wastegate valve to maintain the supercharging pressure below a predetermined level.

NF0347

(1) Wastegate valve

(2) Turbocharger
(3) Wastegate valve controller

While the supercharging pressure is lower than the predetermined level, the wastegate valve is
closed so that entire exhaust gas is directed to the turbine.

NF0348

IN-7

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TURBOCHARGER SYSTEM
Intake (Induction)

When the supercharging pressure reaches the predetermined level, the wastegate controller lets
the supercharging pressure press the diaphragm. This causes the wastegate valve to open
through a linkage. With the wastegate valve open, part of the exhaust gas is allowed to flow into
the exhaust gas pipe that bypasses the passage to the turbine.
This decreases the exhaust gas pressure that rotates the turbine and keeps the supercharging
pressure constant.
D It means P2 – P1 = constant.
P1: Atmospheric pressure
P2: Supercharging pressure

NF0349

2. CONCEPT OF THE WASTEGATE VALVE CONTROL

At high altitudes, the atmospheric pressure (P1) is low, so that the supercharging pressure (P2)
is also low in a conventional system. The wastegate solenoid valve operates in such a way that
a constant supercharging pressure (P2) is maintained by acting in response to change in the atmo-
spheric pressure.

NF0350

IN-8

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TURBOCHARGER SYSTEM
Intake (Induction)

G: INTERCOOLER
D Since the intake air having passed through the turbocharger unit is heated to a very high temper-
ature, the air itself is expanded, resulting in a lower supercharging charging efficiency. The inter-
cooler is provided just before the throttle body to cool down the intake air and improve the super-
charging efficiency.
D The intercooler is an air cooled type. The air delivered from the air duct provided at the engine
hood flows through the core and cools the intake air passing through the intercooler.

S2H1125B

A: Ram air
B: From turbocharger
C: To throttle body

IN-9

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TURBOCHARGER SYSTEM
Intake (Induction)

H: AIR BYPASS VALVE

When a throttle valve is suddenly closed, low air suction noise may occur due to a sudden rise of
the air pressure in the passage between the turbocharger and throttle body. To prevent this, an
air bypass valve and air passage are provided. The air bypass valve, actuated by the vacuum
created by a sudden closure of the throttle valve, allows the suction air to bypass the turbocharger
and flow directly upstream, thus lowering the pressure in the air passage.

S2H1126B

A: To intake manifold
B: To turbocharger inlet duct
C: From intercooler

IN-10

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MECHANICAL ME (SOHC)
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Timing Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Automatic Belt Tension Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Belt Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Valve Rocker Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Camshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Cylinder Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8. Cylinder Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9. Crankshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10. Piston . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
11. Engine Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

ME
SOHC

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GENERAL
Mechanical

1. General
The engine used in this vehicle is of a horizontally opposed, four-cylinder design. This four-stroke-
cycle, water-cooled, SOHC engine uses a total of 16 valves and its main components are made
of aluminum alloy. It is fueled by a multiple fuel injection system.
The engine’s major structural and functional features are as follows:
D The cylinder head forms pentroof combustion chambers, each having a spark plug located at
its center and two each of intake and exhaust valves (four valves per cylinder). The intake and ex-
haust ports are located in a cross-flow arrangement.
D There are a screw and nut at the valve end of each rocker arm. They are used for adjusting the
valve clearance.
D A single timing belt drives two camshafts on the left and right banks and the engine coolant
pump on the left bank. Belt tension is automatically adjusted by a belt tension adjuster, eliminating
need for a manual adjustment.
D The crankshaft is supported by five bearings with high rigidity and strength.
D The cylinder block is an aluminum die casting fitted with iron die-cast cylinder liners.

NF0039

(1) Camshaft (6) Camshaft cap (11) Exhaust rocker arm

(2) Intake valve (7) Valve rocker cover (12) Exhaust rocker shaft
(3) Cylinder block (8) Cylinder head (13) Intake rocker shaft
(4) Connecting rod (9) Oil pan (14) Intake rocker arm
(5) Spark plug (10) Exhaust valve

ME-2

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TIMING BELT
Mechanical

2. Timing Belt
D A single timing belt drives two camshafts (one in the left bank and one in the right bank). The
belt also drives the water pump by its non-toothed side.
D The timing belt teeth have a specially designed round profile which contributes to quiet opera-
tion. The timing belt is made of strong and inflexible core cords, wear-resistant canvas and heat-re-
sistant rubber material.
D A hydraulic automatic belt tension adjuster always keeps the belt taut to the specified tension.
Any manual belt tension adjustment is unnecessary.

NF0040

(1) Timing indicator (For timing mark of crankshaft pulley) (8) Water pump pulley
(2) *Piston position mark (9) Idler No. 2
(3) Belt tension pulley (10) Timing belt
(4) Automatic belt tension adjuster (11) Crankshaft sprocket
(5) Alignment mark (12) Idler
(6) **Piston position mark (13) Camshaft sprocket RH
(7) Camshaft sprocket LH

NOTE:
*: The #1 piston is at TDC when the piston position mark on the crankshaft sprocket is aligned with
the timing mark on the cylinder block.
**: The #1 piston is at TDC on the compression stroke when the piston position mark on the cam-
shaft sprocket is aligned with the timing mark on the belt cover.

ME-3

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AUTOMATIC BELT TENSION ADJUSTER

Mechanical

3. Automatic Belt Tension Adjuster

The automatic belt tension adjuster consists of a tensioner unit and a bracket. It maintains the tim-
ing belt tension automatically at a specified level to enable the belt to transmit power correctly,
reduce operating noise and increase the life of the belt.
The cylinder of the tensioner unit incorporates an adjuster rod, wear ring, plunger spring, return
spring, check ball and silicone oil.
The automatic belt tension adjuster gives tension to the belt by a levering action which is produced
by the push force of the tensioner unit’s adjuster rod. It operates in the process detailed below.

NF0368

(1) Oil seal (8) Plunger spring

(2) Wear ring (9) Check ball
(3) Oil reservoir chamber (10) Timing belt
(4) Return spring (11) Belt tension pulley
(5) Adjuster rod (12) Tensioner bracket
(6) Plunger (13) Cylinder
(7) Oil pressure chamber

ME-4

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AUTOMATIC BELT TENSION ADJUSTER

Mechanical

D Timing belt tensioning action

When the belt becomes slack, the adjuster rod is pushed upward by the return spring. The oil in
the reservoir chamber, which is pressurized by the plunger spring to a certain level, pushes open
the check ball and flows into the oil pressure chamber to keep the pressure constant.
The thrust force F resulting from extension of the adjuster rod applies a counterclockwise torque
to the tensioner bracket, which causes the belt tension pulley at its end to turn in the same direc-
tion. This applies tensioning pressure Pb to the timing belt.
D Timing belt tension balancing action
When the belt tension pulley is pushed against the timing belt with pressure Pb, reaction force Tb
of the timing belt generates the reaction force P at the point on which the adjustor rod force is act-
ing.
This force P pushes the adjuster rod until it balances with the sum of the thrust force F and the
pressure of the oil in the oil pressure chamber. Therefore, the timing belt tension is kept constant.
D Overtension correction action
If the tension of the timing belt increases excessively, the force P becomes larger than the thrust
force F and silicone oil is returned from the oil pressure chamber to the reservoir chamber little by
little until the force P balances again with the thrust force F. Thus the timing belt tension is main-
tained at the specified level at all times.

ME-5

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BELT COVER
Mechanical

4. Belt Cover
D The belt cover is made of lightweight, heat resistant synthetic resin molding. It constitutes a total-
ly enclosed housing with its cylinder block mating edges sealed with rubber gaskets. This effec-
tively protects the inside components from dust and liquid.
D Rubber seals used between the cylinder block and the belt cover effectively reduces transmis-
sion of noise and vibration.
D The front belt cover has a line mark for ignition-timing checking.

NF0042

(1) Front belt cover

(2) Belt cover No. 2 (RH)
(3) Belt cover No. 2 (LH)
(4) Belt cover (LH)

ME-6

178
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VALVE ROCKER ASSEMBLY

Mechanical

5. Valve Rocker Assembly

D The intake valve rocker arms and the exhaust valve rocker arms are installed on their own rocker
shafts both of which are retained by the camshaft caps.
D The valve end of each rocker arm is provided with valve rocker adjusting screw and nut. Turning
of this screw adjusts the valve clearance.
D The exhaust valve rocker arms are Y-shaped, and each arm operates two exhaust valves simul-
taneously.
D Each rocker shaft has an oil passage in it.

NF0043

(1) Valve rocker adjusting screw and nut (4) Camshaft cap
(2) Intake valve rocker arm (5) Supporter
(3) Wave washer (6) Exhaust valve rocker arm

ME-7

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CAMSHAFT
Mechanical

6. Camshaft
D The camshaft is supported inside the cylinder head at four journals.
D The two flanges on each camshaft supports thrust forces to limit the end play of the camshaft
within the tolerance.
D Each camshaft has an oil passage in it.

B2H1987B

(1) Journal
(2) Oil passage
(3) Shaft flange

ME-8

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CYLINDER HEAD
Mechanical

7. Cylinder Head
D The cylinder head is made of aluminium die casting.
D Each combustion chamber in the cylinder head is a compact, pentroof design. The spark plug
is located at the center of the combustion chamber, which contributes to creation of a wide “squish
area” for increased combustion efficiency.
D The two intake and two exhaust valves are arranged on opposite sides for a cross-flow feature.
D The cylinder head gasket is a metallic gasket consisting of three layers of the stainless steel
sheets. It is highly resistant to heat and maintains high level of sealing performance for a long peri-
od.

NF0045

(1) Intake valve (5) Exhaust port

(2) Intake port (6) Exhaust valve
(3) Squish area (7) Spark plug
(4) Combustion chamber

ME-9

181
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CYLINDER BLOCK
Mechanical

8. Cylinder Block
D The cylinder block is made of aluminum die casting. Its open-deck design provides it with such
advantageous features as relatively small weight, high rigidity and excellent cooling efficiency.
D The cylinder liners are made of cast iron. They are dry type which means their outer surfaces
are entirely in contact with the cylinder block.
D The cylinder block supports the crankshaft at its five journals. The journal supporting portions
are designed such that sufficient stiffness and quiet operation are ensured.
D The oil pump is located in the front center of the cylinder block and the engine coolant pump
is located at the front of the left-cylinder bank. At the rear of the right-cylinder bank is an oil separa-
tor which removes oil mist contained in blow-by gas.

ME-10

182
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_S09

CRANKSHAFT
Mechanical

9. Crankshaft
The crankshaft is supported in the cylinder block by five bearings. Each corner formed by a journal
or pin and a web is finished by fillet-rolling method which increases strength of that area. The five
crankshaft bearings are made of aluminum alloy and the No. 5 bearing is provided with a flanged
metal to support thrust forces.

NF0372

ME-11

183
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_S10

PISTON
Mechanical

10. Piston
D The pistons are of a slipper skirt design for reduced weight and friction. The oil control ring
groove utilizes a thermal design.
D The piston pin is offset either downward (Nos. 1 and 3 pistons) or upward (Nos. 2 and 4 pistons).
D The piston head has recesses to prevent interference with the intake and exhaust valves. It also
has engraved marks to identify the piston size and the direction of installation. All the pistons are
common in their design.
D Three piston rings are used for each piston – two compression rings and one oil control ring.
The top piston ring has inner bevels and the second piston ring has an interrupt (cut) on the bottom
outside to reduce oil consumption.

S2H1107B

(1) Location mark (Engine front side) A: Top ring (a) Inner-bevel
(2) Identification mark (Piston size) B: Second ring (b) Interrupt (cut)
(3) Engine capacity (2000 cc) C: Oil ring (c) Upper rail
(d) Spacer
(e) Lower rail

ME-12

184
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_S11

ENGINE MOUNTING
Mechanical

11. Engine Mounting

NF0374

(1) Bracket
(2) Cushion rubber

ME-13

185
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_S11

ENGINE MOUNTING
Mechanical

MEMO

ME-14

186
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D00

DOHC
MECHANICAL ME TURBO
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Timing Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Automatic Belt Tension Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Belt Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Camshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Cylinder Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Cylinder Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8. Crankshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9. Piston . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10. Engine Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

ME
DOHC

187
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D01

GENERAL
Mechanical

1. General
The engine used in this vehicle is of a horizontally opposed, four-cylinder design. This four-stroke-
cycle, water-cooled, DOHC turbocharged eingine uses a total of 16 valves and its main compo-
nents are made of aluminum alloy. It is fueled by a multiple fuel injection system.
The engine’s major structural and functional features are as follows:
D The cylinder head forms pentroof combustion chambers, each having a spark plug located at
its center and two each of intake and exhaust valves (four valves per cylinder). The intake and ex-
haust ports are located in a cross-flow arrangement.
D A single timing belt drives four camshafts on the left and right banks and the engine coolant
pump on the left bank. Belt tension is automatically adjusted by a belt tension adjuster, eliminating
need for a manual adjustment.
D The crankshaft is supported by five bearings with high rigidity and strength.
D The cylinder block is an aluminum die casting fitted with iron die-cast cylinder liners.

NF0366

(1) Intake camshaft (5) Crankshaft (9) Cylinder head

(2) Intake valve (6) Connecting rod (10) Oil pan
(3) Piston (7) Spark plug (11) Exhaust valve
(4) Cylinder block (8) Valve rocker cover (12) Exhaust camshaft

ME-2

188
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D02

TIMING BELT
Mechanical

2. Timing Belt
D A single timing belt drives four camshafts (intake and exhaust camshafts on each bank). The
belt also drives the water pump by its non-toothed side.
D The timing belt teeth have a specially designed round profile which contributes to quiet opera-
tion. The timing belt is made of strong and inflexible core cords, wear-resistant canvas and heat-re-
sistant rubber material.
D A hydraulic automatic belt tension adjuster always keeps the belt taut to the specified tension.
Any manual belt tension adjustment is unnecessary.

NF0367

(1) Timing indicator (For timing mark of crankshaft pulley) (9) Water pump pulley
(2) *Piston position mark (10) Idler No. 2
(3) Belt tension pulley (11) Timing belt
(4) Automatic belt tension adjuster assembly (12) Crankshaft sprocket
(5) Alignment mark (13) Idler
(6) **Piston position mark (14) Exhaust camshaft sprocket RH
(7) Intake camshaft sprocket LH (15) Intake camshaft sprocket RH
(8) Exhaust camshaft sprocket LH

NOTE:
*: The #1 piston is set at the top dead center (TDC) when the piston-position mark on the crankshaft
sprocket is aligned with the mark on cylinder block.
**: The #1 piston is set at TDC on the compression stroke when the piston-position mark on the
camshaft sprocket is facing directly upward.

ME-3

189
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D03

AUTOMATIC BELT TENSION ADJUSTER

Mechanical

3. Automatic Belt Tension Adjuster

The automatic belt tension adjuster consists of a tensioner unit and a bracket. It maintains the tim-
ing belt tension automatically at a specified level to enable the belt to transmit power correctly,
reduce operating noise and increase the life of the belt.
The cylinder of the tensioner unit incorporates an adjuster rod, wear ring, plunger spring, return
spring, check ball and silicone oil.
The automatic belt tension adjuster gives tension to the belt by a levering action which is produced
by the push force of the tensioner unit’s adjuster rod. It operates in the process detailed below.

NF0368

(1) Oil seal (8) Plunger spring

(2) Wear ring (9) Check ball
(3) Oil reservoir chamber (10) Timing belt
(4) Return spring (11) Belt tension pulley
(5) Adjuster rod (12) Tensioner bracket
(6) Plunger (13) Cylinder
(7) Oil pressure chamber

ME-4

190
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AUTOMATIC BELT TENSION ADJUSTER

Mechanical

D Timing belt tensioning action

When the belt becomes slack, the adjuster rod is pushed upward by the return spring. The oil in
the reservoir chamber, which is pressurized by the plunger spring to a certain level, pushes open
the check ball and flows into the oil pressure chamber to keep the pressure constant.
The thrust force F resulting from extension of the adjuster rod applies a counterclockwise torque
to the tensioner bracket, which causes the belt tension pulley at its end to turn in the same direc-
tion. This applies tensioning pressure Pb to the timing belt.
D Timing belt tension balancing action
When the belt tension pulley is pushed against the timing belt with pressure Pb, reaction force Tb
of the timing belt generates the reaction force P at the point on which the adjustor rod force is act-
ing.
This force P pushes the adjuster rod until it balances with the sum of the thrust force F and the
pressure of the oil in the oil pressure chamber. Therefore, the timing belt tension is kept constant.
D Overtension correction action
If the tension of the timing belt increases excessively, the force P becomes larger than the thrust
force F and silicone oil is returned from the oil pressure chamber to the reservoir chamber little by
little until the force P balances again with the thrust force F. Thus the timing belt tension is main-
tained at the specified level at all times.

ME-5

191
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BELT COVER
Mechanical

4. Belt Cover
D The belt cover is made of lightweight, heat resistant synthetic resin molding. It constitutes a total-
ly enclosed housing with its cylinder block mating edges sealed with rubber gaskets. This effec-
tively protects the inside components from dust and liquid.
D Rubber seals used between the cylinder block and the belt cover effectively reduces transmis-
sion of noise and vibration.
D The front belt cover has a line mark for ignition-timing checking.

NF0369

ME-6

192
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D05

CAMSHAFT
Mechanical

5. Camshaft
The DOHC engine uses four camshafts in all; intake and exhaust camshafts on each of the right
and left banks.
The cam lobe noses are finished by “chill” treatment to increase wear resistance and anti-scuffing
properties.
Each camshaft is supported at its three journals and held in position by three camshaft caps. Each
camshaft has a flange which fits in the corresponding groove in the cylinder head to receive thrust
forces generated in the camshaft.

NF0370

(1) Left intake camshaft (4) Left exhaust camshaft

(2) Journal (5) Right intake camshaft
(3) Flange (6) Right exhaust camshaft

ME-7

193
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CYLINDER HEAD
Mechanical

6. Cylinder Head
D The cylinder head is made of aluminium die casting.
D Each combustion chamber in the cylinder head is a compact, pentroof design. The spark plug
is located at the center of the combustion chamber, which contributes to creation of a wide “squish
area” for increased combustion efficiency.
D The two intake and two exhaust valves are arranged on opposite sides for a cross-flow feature.
D The cylinder head gasket is a metallic gasket consisting of three layers of the stainless steel
sheets. It is highly resistant to heat and maintains high level of sealing performance for a long peri-
od.

NF0371

(1) Intake valve (5) Exhaust port

(2) Intake port (6) Exhaust valve
(3) Squish area (7) Spark plug
(4) Combustion chamber

ME-8

194
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CYLINDER BLOCK
Mechanical

7. Cylinder Block
D The cylinder block is made of aluminum die casting. Its open-deck design provides it with such
advantageous features as relatively small weight, high rigidity and excellent cooling efficiency.
D The cylinder liners are made of cast iron. They are dry type which means their outer surfaces
are entirely in contact with the cylinder block.
D The cylinder block supports the crankshaft at its five journals. The journal supporting portions
are designed such that sufficient stiffness and quiet operation are ensured.
D The oil pump is located in the front center of the cylinder block and the engine coolant pump
is located at the front of the left-cylinder bank. At the rear of the right-cylinder bank is an oil separa-
tor which removes oil mist contained in blow-by gas.

ME-9

195
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D08

CRANKSHAFT
Mechanical

8. Crankshaft
The crankshaft is supported in the cylinder block by five bearings. Each corner formed by a journal
or pin and a web is finished by fillet-rolling method which increases strength of that area. The five
crankshaft bearings are made of aluminum alloy and the No. 5 bearing is provided with a flanged
metal to support thrust forces.

NF0372

ME-10

196
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ME_D09

PISTON
Mechanical

9. Piston
D The pistons are of a slipper skirt design for reduced weight and friction. The oil control ring
groove utilizes a thermal design.
D The piston pin is offset either downward (Nos. 1 and 3 pistons) or upward (Nos. 2 and 4 pistons).
D The piston head has recesses to prevent interference with the intake and exhaust valves. It also
has engraved marks to identify the piston size and the direction of installation. All the pistons are
common in their design.
D Three piston rings are used for each piston – two compression rings and one oil control ring.
The top piston ring has inner bevels and the second piston ring has an interrupt (cut) on the bottom
outside to reduce oil consumption.

NF0373

(1) Identification mark A: Top ring (a) Inner-bevel

(2) Location mark (Engine front side) B: Second ring (b) Interrupt (cut)
C: Oil ring (c) Upper rail
(d) Spacer
(e) Lower rail

ME-11

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ENGINE MOUNTING
Mechanical

10. Engine Mounting

NF0374

(1) Bracket
(2) Cushion rubber

ME-12

198
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EXHAUST EX (SOHC)
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

EX
SOHC

199
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GENERAL
Exhaust

1. General
D The exhaust system consists of front exhaust pipes, catalytic converters, a center exhaust pipe,
a rear exhaust pipe and a muffler. The front catalytic converter is located immediately behind the
front exhaust pipe, and the rear catalytic converter is incorporated in the center exhaust pipe.
D The exhaust system features an improved sound suppression design; the two branches of the
front exhaust pipe join at a point almost equal in distance from the engine’s exhaust ports and the
rear exhaust pipe has resonance chambers in addition to a muffler of 16 liters (976.4 cu in) capac-
ity.

EX-2

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COMPOSITION
Exhaust

2. Composition

S2H2145A

(1) Front exhaust pipe RH (6) Center exhaust pipe

(2) Front exhaust pipe LH (7) Rear catalytic converter
(3) Front catalytic converter (8) Resonance chamber
(4) Front oxygen (A/F) sensor (9) Rear exhaust pipe
(5) Rear oxygen sensor (10) Muffler

EX-3

201
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EX_S02

COMPOSITION
Exhaust

MEMO

EX-4

202
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EX_S-OBD00

SOHC
w/o
EXHAUST EX OBD
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

EX
SOHC
–OBD

203
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EX_S-OBD01

GENERAL
Exhaust

1. General
D The exhaust system consists of front exhaust pipes, catalytic converter(s)*, a center exhaust
pipe, a rear exhaust pipe and a muffler. In the system with two catalytic converters, the front catalyt-
ic converter is located immediately after the front exhaust pipe and the rear catalytic converter is
incorporated in the center exhaust pipe.
*: Regarding the catalytic converter, there are three versions – without catalytic converter, with a
single catalytic converter (Australia spec. vehicles), and with two catalytic converters.
D The exhaust system features an improved sound suppression design; the two branches of the
front exhaust pipe join at a point almost equal in distance from the engine’s exhaust ports and the
rear exhaust pipe has resonance chambers in addition to a muffler of 16 liters (976.4 cu in) in ca-
pacity.

EX-2

204
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COMPOSITION
Exhaust

2. Composition
A: WITH SINGLE CATALYTIC CONVERTER (AUSTRALIA SPEC. VEHICLE)

S2H0563B

(1) Front exhaust pipe RH (5) Center exhaust pipe

(2) Front exhaust pipe LH (6) Resonance chamber
(3) Catalytic converter (7) Rear exhaust pipe
(4) Oxygen sensor (8) Muffler

B: WITH TWO CATALYTIC CONVERTERS (EXCEPT AUSTRALIA SPEC. VE-

HICLE)

S2H1103B

(1) Front exhaust pipe RH (6) Rear catalytic converter

(2) Front exhaust pipe LH (7) Resonance chamber
(3) Front catalytic converter (8) Rear exhaust pipe
(4) Oxygen sensor (9) Muffler
(5) Center exhaust pipe

EX-3

205
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COMPOSITION
Exhaust

C: WITHOUT CATALYTIC CONVERTER

S2H0562B

(1) Front exhaust pipe RH (4) Resonance chamber

(2) Front exhaust pipe LH (5) Rear exhaust pipe
(3) Center exhaust pipe (6) Muffler

EX-4

206
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DOHC
EXHAUST EX TURBO
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

EX
DOHC

207
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EX_D01

GENERAL
Exhaust

1. General
D The exhaust system consists of left and right exhaust manifolds, a front joint pipe, a turbocharger
joint pipe, a center exhaust pipe, a rear exhaust pipe and a muffler. The turbocharger joint pipe
incorporates the precatalytic converter, the center exhaust pipe incorporates the front catalytic
converter, and the rear exhaust pipe incorporates the rear catalytic converter*.
*: The Australia spec. vehicles are not equipped with rear catalytic converters.
D The exhaust system features an improved sound suppression design; the rear exhaust pipe has
a resonance chamber in addition to a large capacity muffler.

EX-2

208
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. EX_D02

CONSTRUCTION
Exhaust

2. Construction
A: EUROPE SPEC. VEHICLE

S2H2167A

(1) Left exhaust manifold (8) Center exhaust pipe

(2) Front joint pipe (9) Rear catalytic converter
(3) Front oxygen (A/F) sensor (10) Rear oxygen sensor
(4) Exhaust temperature sensor (11) Chamber
(5) Right exhaust manifold (12) Rear exhaust pipe
(6) Precatalytic converter (13) Muffler
(7) Front catalytic converter (14) Turbocharger joint pipe

B: AUSTRALIA SPEC. VEHICLE

S2H2238A

(1) Left exhaust manifold (8) Center exhaust pipe

(2) Front joint pipe (9) Rear oxygen sensor
(3) Front oxygen (A/F) sensor (10) Chamber
(4) Exhaust temperature sensor (11) Rear exhaust pipe
(5) Right exhaust manifold (12) Muffler
(6) Precatalytic converter (13) Turbocharger joint pipe
(7) Front catalytic converter

EX-3

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CONSTRUCTION
Exhaust

MEMO

EX-4

210
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO00

COOLING CO
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Cooling Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Water Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Mechanical Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Radiator Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

CO

211
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO01

GENERAL
Cooling

1. General
D The engine cooling system consists of a down-flow radiator which features high heat-dissipation
performance, an electric-motor-driven fan, a water pump, a thermostat, and an engine coolant
temperature sensor.
D The reservoir tank is designed to eliminate the need for replenishing coolant.
D The ECM controls the operation of the radiator main fan and sub fan depending on the signals
from the engine coolant temperature sensor, vehicle speed sensor and A/C switch.

CO-2

212
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO02

COOLING CIRCUITS
Cooling

2. Cooling Circuits
A: NON-TURBO MODEL
The cooling system operates in three different phases depending on the temperature of the engine
coolant.
D 1st phase (thermostat closed)
When the engine coolant temperature is below 76°C (169°F), the thermostat remains closed. The
coolant flows through the bypass and heater circuits.
This permits the engine to warm up quickly.
D 2nd phase (thermostat open)
When the engine coolant temperature is above 76 – 80°C (169 – 176°F), the thermostat opens.
The coolant flows through the radiator where it is cooled.
D 3rd phase (thermostat open and radiator fan operating)
When the engine coolant temperature sensor sends a signal indicating a temperature above 95°C
(203°F) to the ECM, it causes the radiator fan (or fans) to operate.

S2H1119A

CO-3

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO02

COOLING CIRCUITS
Cooling

B: TURBO MODEL
The cooling system operates in three different phases depending on the temperature of the engine
coolant.
D 1st phase (thermostat closed)
When the engine coolant temperature is below 76°C (169°F), the thermostat remains closed. The
coolant flows through the bypass and heater circuits.
This permits the engine to warm up quickly.
D 2nd phase (thermostat open)
When the engine coolant temperature is above 76 – 80°C (169 – 176°F), the thermostat opens.
The coolant flows through the radiator where it is cooled.
D 3rd phase (thermostat open and radiator fan operating)
When the engine coolant temperature sensor sends a signal indicating a temperature above 95°C
(203°F) to the ECM, it causes the radiator fan (or fans) to operate.
When the engine is stopped after high-speed operation, vapor produced in the turbocharger cool-
ing section flows from the coolant filler tank to the reservoir tank where it condenses back into wa-
ter.
Water is then absorbed by the coolant filler tank as the engine cools down.

NF0363

CO-4

214
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO03

WATER PUMP
Cooling

3. Water Pump
The water pump is located in the front portion of the left bank cylinder block and is driven by the
engine through the timing belt. The thermostat is fitted into the coolant inlet at the bottom of the
water pump. When the pump’s impeller rotates, the coolant is drawn into the pump from the lower
pipe (which is connected to the radiator hose) via the thermostat. It then flows along the perimeter
of the impeller and then is discharged for circulation through a circuit depending on the coolant
temperature.
A: NON-TURBO MODEL

NF0050

(1) Pulley (3) Mechanical seal (5) Thermostat

(2) Ball bearing (4) Impeller (6) Thermostat case

CO-5

215
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO03

WATER PUMP
Cooling

B: TURBO MODEL

NF0051

(1) Pulley (3) Mechanical seal (5) Thermostat

(2) Ball bearing (4) Impeller (6) Thermostat case

CO-6

216
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO04

MECHANICAL SEAL
Cooling

4. Mechanical Seal
The mechanical seal has its seat tightly fitted on the water pump shaft. Since it is a hermetic seal
forming an integral part of the water pump, the water pump cannot be disassembled.

NF0052

(1) Carbon seal

(2) Ceramics seat
(3) Water pump shaft

CO-7

217
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO05

THERMOSTAT
Cooling

5. Thermostat
The thermostat has a totally-enclosed wax pellet which expands as the coolant temperature in-
creases. It opens and closes accurately at the preset temperatures and features high durability.

NF0053

(1) Valve (4) Piston (7) Stop ring

(2) Spring (5) Guide (8) Wax element
(3) Stopper (6) Rubber packing (9) Jiggle valve

CO-8

218
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO06

RADIATOR FAN
Cooling

6. Radiator Fan
A: DESCRIPTION
Each radiator fan is made of plastic. It is driven by an electric motor which is retained on a shroud.

H2H3243A

(1) Radiator (6) Reservoir tank cap

(2) Radiator sub fan (model with A/C) (7) Reservoir tank
(3) Radiator sub fan motor (model with A/C) (8) Radiator main fan shroud
(4) Radiator sub fan shroud (model with A/C) (9) Radiator main fan
(5) Over flow hose (10) Radiator main fan motor
A/C: Air conditioner

CO-9

219
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CO06

RADIATOR FAN
Cooling

B: FUNCTION
The operation of the radiator fan is controlled by the ECM. In a model equipped with an air condi-
tioning system (A/C), the ECM uses for the control the signals from the engine coolant temperature
sensor, vehicle speed sensor and A/C switch. The ECM on a model without an A/C performs the
control based on the signal from the engine coolant temperature sensor.
1. MODEL WITH A/C
Engine coolant temperature
Lower than 95°C Between 95 and 99°C Higher than 100°C
A/C com- (203°F) (203 and 210°F) (212°F)
Vehicle speed
pressor
Operation of radiator fans Operation of radiator fans Operation of radiator fans
Main fan Sub fan Main fan Sub fan Main fan Sub fan
Lower than 19 km/h OFF OFF OFF ON OFF ON ON
(12 MPH)
ON ON ON ON ON ON ON
Between 20 and 69 km/h OFF OFF OFF ON OFF ON ON
(12 and 43 MPH)
ON ON ON ON ON ON ON
Between 70 and 89 km/h OFF OFF OFF OFF OFF ON ON
(43 and 55 MPH)
ON ON OFF ON ON ON ON
Higher than 90 km/h OFF OFF OFF OFF OFF ON ON
(56 MPH)
ON OFF OFF ON OFF ON ON

2. MODEL WITHOUT A/C

Engine coolant temperature
Lower than 95°C Between 95 and 99°C Higher than 100°C
Vehicle speed
(203°F) (203 and 210°F) (212°F)
Operation of radiator main fan Operation of radiator main fan Operation of radiator main fan
Lower than 19 km/h OFF ON ON
(12 MPH)
Between 20 and 69 km/h OFF ON ON
(12 and 43 MPH)
Between 70 and 89 km/h OFF OFF ON
(43 and 55 MPH)
Higher than 90 km/h OFF OFF ON
(56 MPH)

CO-10

220
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU00

LUBRICATION LU
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Engine Oil Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Oil Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Oil Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Oil Pan and Oil Strainer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Oil Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7. Oil Cooler (Turbo Model Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

LU

221
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU01

GENERAL
Lubrication

1. General
D The lubrication system force-circulates engine oil throughout the engine using an oil pump. The
oil pressure is regulated by the relief valve built into the oil pump.
D The oil pump is a thin, large-diameter trochoid rotor type which can accommodate the engine’s
high output. The pump is directly driven by the crankshaft.
D The engine oil is cleaned by a full-flow, paper element type oil filter. The filter has a bypass valve
which allows the engine oil to flow bypassing the filter if it is clogged.
D The inside of the oil pan is fitted with a baffle plate which reduces changes in the oil level due
to movement of the vehicle, thus ensuring uninterrupted suction of oil.
D The engine oil discharged from the oil pump is delivered to the journal bearings, connecting rod
bearings, and other parts requiring lubrication and cooling via the vertical passage in the right
bank of the cylinder block, the oil filter, and the oil galleries in the right and left banks of the cylinder
block.
D The engine oil is also distributed to each cylinder head valve mechanism at a proper flow rate
achieved by metering by the orifice provided in each oil gallery.
D A water-cooled oil cooler is located between the oil filter and cylinder block to keep the engine
oil in an optimum temperature range and prevent degradation of lubrication performance (Turbo
model).

LU-2

222
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU01

GENERAL
Lubrication

A: NON-TURBO MODEL

NF0057

(1) Oil filter (5) Roller

(2) Oil pump (6) Rocker arm
(3) Oil strainer (7) Rocker shaft
(4) Camshaft
(a) Bypass valve opening pressure:
157 kPa (1.6 kgf/cm2, 23 psi)
(b) Relief valve opening pressure:
490 kPa (5.0 kgf/cm2, 71 psi)

LU-3

223
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU01

GENERAL
Lubrication

B: TURBO MODEL

NF0058

(1) Oil filter (4) Oil strainer

(2) Oil cooler (5) Intake gallery
(3) Oil pump (6) Exhaust gallery
(a) Bypass valve opening pressure:
157 kPa (1.6 kgf/cm2, 23 psi)
(b) Relief valve opening pressure:
588 kPa (6.0 kgf/cm2, 85 psi)

LU-4

224
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU02

ENGINE OIL FLOW

Lubrication

2. Engine Oil Flow

A: NON-TURBO MODEL

NF0059

LU-5

225
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU02

ENGINE OIL FLOW

Lubrication

B: TURBO MODEL

NF0060

LU-6

226
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU03

OIL PUMP
Lubrication

3. Oil Pump
D The oil pump is a trochoid rotor type consisting of an inner rotor and outer rotor assembled with
each other in a pump body. When the inner rotor is driven by the crankshaft, the outer rotor is ro-
tated, changing the space between it and the inner rotor. The change in the space occurs because
of the difference in the number of teeth between the rotors.
D Engine oil is drawn into the large space created near the inlet of the pump. It is then carried to
the discharge port. As the pump rotates, the space carrying the oil becomes smaller, thus the oil
is pressurized and discharged from the outlet port. Oil pressure is regulated by the relief valve built
into the pump. Excess oil is directly returned to the inlet port.

NF0061

(1) Inner rotor (6) Plug

(2) Outer rotor (7) Gasket
(3) Oil seal (8) Relief valve spring
(4) Oil pump case (9) Relief valve
(5) Oil pump cover

LU-7

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OIL FILTER
Lubrication

4. Oil Filter
The oil filter is a full-flow filtering, cartridge type that utilizes a paper element. It also has a built-in
bypass valve. The filter element has a special pleat design to increase the effective filtering area.

S2H0249B

(1) Oil seal

(2) Filter body
(3) Bypass valve
(4) Pleated element

LU-8

228
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. LU05

OIL PAN AND OIL STRAINER

Lubrication

5. Oil Pan and Oil Strainer

D The oil pan is attached to the cylinder block using liquid gasket for sealing. The oil strainer is
a metal net type and removes large foreign particles from the engine oil. It is located in the middle
of the oil pan. The pipe from the strainer is connected to the suction port of the oil pump in the left
bank of the cylinder block.
D There is a baffle plate in the oil pan, near the bottom of the cylinder block. It stabilizes the oil level
and reinforces the oil pan.

LU-9

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OIL PAN AND OIL STRAINER

Lubrication

A: NON-TURBO MODEL

S2H0852B

B: TURBO MODEL

S2H0250B

(1) Oil strainer (a) LOW level

(2) Level gauge guide (b) FULL level (Engine HOT condition)
(3) Baffle plate (c) FULL level (Engine COLD condition)
(4) Oil level gauge

LU-10

230
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OIL PRESSURE SWITCH

Lubrication

6. Oil Pressure Switch

The oil pressure switch is located in the front upper portion of the right cylinder block bank. The
purpose of this switch is to monitor the operation of the oil pump as well as the lubricating oil pres-
sure when the engine is running.

NF0065

(1) Contact point (4) Molded portion

(2) Diaphragm (5) Terminal
(3) Spring

1) When oil pressure does not build up (immediately after ignition switch is turned ON):
The diaphragm is pushed toward the cylinder block by the spring force (a force equivalent to the
specified oil pressure). This closes the contact points, causing the oil pressure warning light in the
combination meter to illuminate.
2) When oil pressure reaches the specified value (after engine starts):
After reaching the specified value of 14.7 kPa (0.15 kgf/cm2, 2.1 psi), the oil pressure pushes the
diaphragm overcoming the spring force. This opens the contact points and the oil pressure warn-
ing light goes out.

LU-11

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OIL COOLER (TURBO MODEL ONLY)

Lubrication

7. Oil Cooler (Turbo Model Only)

The oil cooler used in models is of a water cooled type. It serves to maintain engine oil in proper
temperature range and so prevent degradation of lubricating oil performance.

NF0360

(1) Oil cooler (3) Connector

(2) Water pipe (4) Oil filter

LU-12

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SPEED CONTROL SYSTEM SP

Page
1. General ................................................................................2

SP

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GENERAL
Speed Control System

1. General
The accelerator outer cable is secured to the accelerator pedal bracket rather than to the toe-
board. Securing the outer cable in this way has a merit of making the ratio of throttle valve move-
ment to cable stroke less variable. This arrangement is also effective to prevent unsmooth cable
return movement that may result from deformation of the toeboard or improper installation of the
accelerator pedal and, therefore, to improve safety.

S2H2225A

(1) Accelerator cable (4) Bracket

(2) Toeboard (5) Casing cap
(3) Accelerator pedal (6) Holder

SP-2

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IGNITION IG (SOHC)
Page
1. Ignition Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Spark Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

IG
SOHC

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IGNITION COIL
Ignition

1. Ignition Coil
Ignition coils are made integral with an ignitor.
The ignition system is of a dual-ignition-coil design, each coil causing two plugs to generate
sparks simultaneously. In response to the signal from the ECM, the ignitor supplies current to an
ignition coil and the ignition coil supplies high-voltage current to a pair of spark plugs (#1 and #2
or #3 and #4) simultaneously.

B6H0910A

(1) Ignition coil and ignitor assembly

NF0035

(1) ECM (5) Spark plug #2

(2) Ignitor (6) Spark plug #3
(3) Ignition coil (7) Spark plug #4
(4) Spark plug #1 (8) Ignition switch

IG-2

236
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SPARK PLUG
Ignition

2. Spark Plug
The spark plug’s thread diameter is 14 mm (0.551 in) and the gap is controlled to a value between
1.0 and 1.1 mm (0.039 and 0.043 in).

NF0036

IG-3

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SPARK PLUG
Ignition

MEMO

IG-4

238
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. IG_S-OBD00

SOHC
w/o
IGNITION IG OBD IG
SOHC
–OBD
Page
1. Ignition Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Spark Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

239
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IGNITION COIL
Ignition

1. Ignition Coil
Ignition coils are made integral with an ignitor.
The ignition system is of a dual-ignition-coil design, each coil causing two plugs to generate
sparks simultaneously. In response to the signal from the ECM, the ignitor supplies current to an
ignition coil and the ignition coil supplies high-voltage current to a pair of spark plugs (#1 and #2
or #3 and #4) simultaneously.

S2H2134A

(1) Ignition coil and ignitor assembly

NF0035

(1) ECM (5) Spark plug #2

(2) Ignitor (6) Spark plug #3
(3) Ignition coil (7) Spark plug #4
(4) Spark plug #1 (8) Ignition switch

IG-2

240
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. IG_S-OBD02

SPARK PLUG
Ignition

2. Spark Plug
The spark plug’s thread diameter is 14 mm (0.551 in) and the gap is controlled to either of the di-
mensions shown below.

NF0399

IG-3

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. IG_S-OBD02

SPARK PLUG
Ignition

MEMO

IG-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. IG_D00

DOHC
IGNITION IG TURBO
Page
1. Ignition Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 IG
DOHC
2. Spark Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

243
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. IG_D01

IGNITION COIL
Ignition

1. Ignition Coil
The engine uses a direct ignition system with one ignition coil mounted for each cylinder (or spark
plug).
The secondary terminal of the ignition coil is in contact with the spark plug terminal nut.
Since no spark plug cable is used, secondary voltage drop, leaks, or other problems that are in-
herent in a system using spark plug cables do not occur. The result is high performance and high
reliability.

NF0316

IG-2

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SPARK PLUG
Ignition

2. Spark Plug
The spark plug has a platinum tipped electrode. The thread diameter is 14 mm (0.551 in) and the
gap is controlled to a value between 0.7 and 0.8 mm (0.028 and 0.031 in).

NF0317

IG-3

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SPARK PLUG
Ignition

MEMO

IG-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SC00

STARTING/CHARGING SC
Page
1. Starter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SC

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SC01

STARTER
Starting/Charging

1. Starter
The starter is of a reduction type. Its output is 1.0 kW on the MT model and 1.4 kW on the AT model.

NF0364

SC-2

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SC02

GENERATOR
Starting/Charging

2. Generator
The generator has a built-in regulator which provides diagnostic functions in addition to a voltage
regulating function as follows:
1) Voltage regulation
The on-off operation of transistor Tr1 connects and disconnects the field current circuit, providing
a constant level of output voltage.
2) Diagnosis warning
When any of the following problems occur, the charge lamp illuminates.
a. No voltage generation
Brush wear exceeds specified wear limits, field coil circuit is broken, etc.
b. Excessive output
Output voltage is greater than 16 volts (approx).
c. Terminal B disconnection
Harness is disconnected from alternator terminal B.
d. Terminal S disconnection
Harness is disconnected from alternator terminal S. In this case, voltage is slightly greater than
specified regulated voltage; however, voltage regulation is still controlled and the battery is
prevented from becoming overcharged.

NF0365

SC-3

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SC03

BATTERY
Starting/Charging

3. Battery
The battery is located in the left front part of the engine compartment. It is held on a tray by the
battery holder.

SC-4

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CONTROL SYSTEM CS
Page
1. Gear Shift Lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Select Lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Dual Range Selector Lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

CS

251
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GEAR SHIFT LEVER

Control System

1. Gear Shift Lever

The manual transmission’s gear shift lever system is a parallel link type whose stay is mounted
through a cushion rubber.

S3H0003A

(1) Knob (5) Stay

(2) Gear shift lever (6) Bush
(3) Cushion rubber (7) Joint
(4) Boot (8) Rod

CS-2

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SELECT LEVER
Control System

2. Select Lever
D The select lever moves through seven positions. Since movement of the lever is restricted by
gates in the guide and a pin on the lever, it can always be retained correctly in a desired position.
Before shifting the lever from P to R, 3 to 2, N to R or R to P, a button on the lever is pressed to unlock
the lever.
D To transmit movements of the select lever to the transmission, a push-pull cable is used.
D The detent spring is a new addition to the select lever mechanism. It ensures more precise posi-
tioning of the select lever.
D A plastic select lever base plate is used.

B3H0641A

(1) Button (5) Base plate

(2) Select lever (6) Push-pull cable
(3) Detent arm (7) Pin
(4) Detent spring (8) Guide

CS-3

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DUAL RANGE SELECTOR LEVER

Control System

3. Dual Range Selector Lever

The dual range selector lever is provided behind the transmission shift lever. Moving the range
selector lever up and down shifts the Hi-Lo coupling sleeve of the auxiliary transmission gear
mechanism via a cable, thereby selecting the low range and high range, respectively.

S3H0055A

(1) Cable
(2) Grommet
(3) Range selector lever assembly

CS-4

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AUTOMATIC TRANSMISSION AT
Page
1. Electrohydraulic Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Transmission Control Module (TCM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3. On-board Diagnostics System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4. Fail-safe Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5. Transmission Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

AT

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

1. Electrohydraulic Control System

A: GENERAL
The electrohydraulic control system for the transmission and transfer consists of various sensors
and switches, a transmission control module (TCM) and the hydraulic controlling units including
solenoid valves. The system controls the automatic transmission operation, including gear shift-
ing, lock-up clutch operation, line pressure, automatic control pattern selection (“Base” and “Pow-
er”), and gear-shift timing. It also controls the operation of the transfer clutch. The TCM determines
vehicle operating conditions from various input signals and controls a total of eight solenoids (shift
solenoids 1 and 2, low clutch timing solenoid, 2-4 brake timing solenoid, line pressure duty sole-
noid, lock-up duty solenoid, transfer duty solenoid, and 2-4 brake duty solenoid) by sending ap-
propriate signals to them.

S3H0638A

AT-2

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

B: INPUT SIGNALS
Signal name Major function
Indicates the throttle valve position. This signal is used to determine shift point, line
Throttle position sensor
pressure, and lock-up engaging vehicle speed, which vary with engine load.
Front vehicle speed sensor Indicates the vehicle speed. This signal is used for control of gear shifting, lock-up
(located on transmission case) engaging, line pressure, and transfer clutch operation.
Rear vehicle speed sensor Used to control transfer clutch, and also as backup signal in case of failure of front
(located on extension case) vehicle speed sensor.
Indicates the engine speed. This signal is used for control of lock-up clutch to en-
Engine speed signal
sure smooth engagement.
Used to determine gears and line pressures in each of ranges “P”, “R”, “N”, “D”,
Inhibitor switch
“3”, “2” and “1”.
Indicates the ATF temperature. This signal is used for inhibition of lock-up, release
ATF temperature sensor
of OD and determination of ATF temperature.
Used to change the mode from AWD to FWD. Also used to adapt the vehicle to
FWD switch FWD tester roller. Changeover from AWD to FWD can be made by inserting a fuse
into the fuse holder.
Used when ABS is operating to optimize ABS control. In this control, transfer
ABS signal clutch torque load capacity is adjusted to eliminate the influence of engine braking
and reduce the degree of coupling between front and rear wheels.
Indicates operation of cruise control system. It is used to expand “4th” operating
Cruise control signal
range.
Tells the rotation speed of the input shaft. The proportion of this speed to the ve-
Torque converter turbine speed sensor
hicle speed determines whether shifting should be made or not.
Torque control cut signal Sent from engine control module (ECM) to TCM to inhibit the torque control.
Intake manifold pressure signal Used to determine line pressure of gear shifting.
(Non-turbo model)
Mass air flow signal (Turbo model) Used to determine line pressure of shift change.
With this switch “ON”, the vehicle starts in 2nd gear (if the D, 3 or 2 range is se-
HOLD switch
lected), which facilitates drive away on a slippery road.
With this switch “ON”, the TCM controls gear shifting in the POWER mode which is
POWER switch
convenient when rapid acceleration or great power is required.
Kickdown switch Indicates full throttle opening. TCM uses this signal to make kickdown control.
If this signal is issued during downhill driving, TCM makes shift down control,
Brake switch
causing the vehicle speed to be reduced.

AT-3

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

C: OUTPUT SIGNALS
Signal name Function
Each of these signals controls shift step by turning the corresponding solenoid ON/
Shift solenoid 1, 2
OFF. Activating timing is controlled for each solenoid to reduce shift shock.
Line pressure duty solenoid Regulates the line pressure according to driving conditions.
Regulates the hydraulic pressure of the lock-up clutch to operate it in three modes
Lock-up duty solenoid
(open, smooth and lock-up).
Regulates the hydraulic pressure of the transfer clutch to control the driving force to
Transfer duty solenoid
the rear drive shaft.
Causes the light to illuminate when ATF becomes excessively hot (exceeds a set tem-
AT OIL TEMP light
perature level).
2-4 brake duty solenoid Regulates 2-4 brake operating pressure to reduce shifting shocks.
Switches on or off the pressure acting on 2-4 brake timing valve B to control the re-
2-4 brake timing solenoid
lease timing of the 2-4 brake.
Switches on or off the pressure acting on the low clutch timing valve B to control the
release timing of the low clutch.
Low clutch timing solenoid
Also switches on or off the pressure acting on the reverse inhibit valve to control the
reverse inhibit function.
Torque control signal 1 Reduces engine torque during range selection and gear change.
Torque control signal 2 Reduces engine torque during range selection and gear change.
Indicates whether the shift pattern is “Base” or “Power”. The indicator lights in the
POWER indicator light POWER mode. This light is also used to display diagnostic trouble codes for the on-
board diagnosis function.

AT-4

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

D: CONTROL ITEMS
Control item Description of control
Base shift control
Upshifting and downshifting are set for each range, gear
D Base pattern
and pattern according to throttle position and vehicle speed.
D Power pattern
ABS-in-operation control Gear is locked in 3rd when ABS signal enters.
ATF-low-temperature con- Shifting into 4th gear is prevented when ATF temperature is
trol below the preset value.
Gear shift control
With HOLD switch ON, vehicle starts in 2nd gear (if the D, 3
Hold control
or 2 range is selected).
Power pattern control
Power pattern is selected when POWER switch is ON.
(POWER light ON)
Base pattern control
Base pattern is selected when POWER switch is OFF.
(POWER light OFF)
Lock-up ON is set for D-range 4th gear; ON/OFF is set for
Transmission all gears (except D-range 4th) and patterns. Lock-up control
control Base lock-up control
Lock-up control is performed according to throttle position and vehicle
speed. (Basically lock-up is OFF during gear shifting.)
Smooth control Smooth lock-up is performed when lock-up is switched on.
Line pressure is regulated according to throttle position,
Ordinary control
vehicle speed and range signals.
Line pressure con- Line pressure is regulated when shifting to lessen shifting
Shifting control
trol shock.
Line pressure is lowered to a minimum so as to reduce en-
Starting control
gine cranking load.
Shift step control ON/OFF timing for shift solenoid is controlled.
Lock-up control When shifting, the lock-up clutch is temporarily released.
Shiftt timing control
Shi
When shifting, line pressure is controlled to the optimum
Line pressure control
level so as to reduce shifting shock.
Transfer clutch pressure is regulated according to the
Ordinary transfer control
throttle valve angle and vehicle speed.
1 range control Transfer clutch pressure is increased.
Immediately after detecting a slip, transfer clutch pressure is
AWD transfer controlled to the same pressure as 1 range. (This control is
Slip control
clutch control canceled if V y 60 km/h (37 MPH), or when throttle valve is
closed fully.)
Control in turns Transfer clutch pressure is reduced after detecting a turn.
Transfer clutch pressure is adjusted to a set level immedi-
ABS-in-operation control
ately after reception of ABS signal.

AT-5

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

E: POWER INDICATOR LIGHT

The automatic transmission equipped vehicle is capable of selecting either of the two control pat-
terns; the Base pattern suitable for ordinary driving and the Power pattern suitable for uphill driving
or rapid acceleration. The POWER indicator light on combination meter lights when the Power pat-
tern is selected. See the table below.
Selector lever position Change of pattern POWER indicator light
“D”, “3”, “2” range Power pattern is selected when the pow- D “Base” pattern: OFF
er switch is ON. D “Power” pattern: ON

F: THROTTLE POSITION SENSOR

The throttle position sensor provides electrical signals corresponding to throttle valve positions.
The throttle valve angular position and accelerator depressing speed are detected by this throttle
position sensor.

G: REAR VEHICLE SPEED SENSOR

This vehicle speed sensor (output shaft speed sensor) is externally mounted on the extension
case. It detects the rear wheel speed in terms of the peripheral speed of the transfer clutch drum
and sends sine wave signals (30 pulses per rotation) to the TCM.

NF0068

(1) Rear vehicle speed sensor

AT-6

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

H: FRONT VEHICLE SPEED SENSOR

This vehicle speed sensor (output shaft speed sensor) is externally mounted on the transmission
case. It detects the front wheel speed and sends sine wave signals (16 pulses per rotation) to the
TCM.
The TCM converts the signals into pulse signals and outputs them to both the engine control mod-
ule (ECM) and the combination meter.

NF0069

(1) Front vehicle speed sensor

I: ATF TEMPERATURE SENSOR

This sensor is located in the hydraulic control valve of the transmission. It detects the temperature
of ATF and outputs it as an electrical resistance signal. The output characteristics of the sensor
are shown below.

NF0071

(1) ATF temperature sensor

AT-7

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

J: TORQUE CONVERTER TURBINE SPEED SENSOR

The torque converter turbine speed sensor (output shaft speed sensor) is externally mounted on
the transmission case.
The sensor detects the torque converter turbine speed in terms of the rotation speed of the periph-
ery of the high clutch drum coupled to the input shaft, and sends sine wave signals (32 pulses per
rotation) to the TCM. The TCM calculates the proportion of the input shaft speed to the vehicle
speed and determines whether the shifting is to be made or not.

NF0072

(1) Torque converter turbine speed sensor

AT-8

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

K: INHIBITOR SWITCH
The inhibitor switch assures safety when starting the engine. This switch is mounted on the right
side of the transmission case, and is operated by the selector lever.
When the selector lever is set to P or N, the electrical circuit in the inhibitor switch is closed and
the starter circuit is completed for cranking the engine.
When the selector lever is in the R, D, 3, 2 or 1 range, the electrical circuit in the inhibitor switch
is open. Hence engine cranking is disabled. In the R range, the backup light circuit is completed
in the switch, and the backup lights come on.
In addition to the above function, the inhibitor switch incorporates a circuit for detecting the se-
lected range position and sending the range signal to the TCM.

NF0073

Range position Pin No.

(4) – (3)
P
(12) – (11)
(4) – (2)
R
(10) – (9)
(4) – (1)
N
(12) – (11)
D (4) – (8)
3 (4) – (7)
2 (4) – (6)
1 (4) – (5)

AT-9

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

L: SHIFT SOLENOIDS 1 AND 2

These solenoids are located in the transmission hydraulic control valve. They are turned ON or
OFF according to signals from the TCM. The gear positions are changed according to the ON and
OFF condition of these solenoids.

NF0074

(1) Shift solenoid 2

(2) Shift solenoid 1

M: LOW CLUTCH TIMING SOLENOID

This solenoid is located in the transmission hydraulic control valve. It is turned ON or OFF accord-
ing to signals from the TCM. It then controls the low clutch timing valve B and reverse inhibitor
valve.

NF0075

(1) Low clutch timing solenoid

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

N: 2-4 BRAKE TIMING SOLENOID

This solenoid is located in the transmission hydraulic control valve. It is turned ON or OFF accord-
ing to signals from the TCM. It then controls the 2-4 brake timing valve B to decrease the change
gear shock.

NF0076

(1) 2-4 brake timing solenoid

O: LINE PRESSURE DUTY SOLENOID

This solenoid is located in the transmission hydraulic control valve. Its duty ratio is controlled by
signals from the TCM. This solenoid then controls the pressure modifier valve and accumulator
control valve A to adjust the line pressure to an optimum pressure level suitable for operating
conditions.

NF0077

(1) Line pressure duty solenoid

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

P: LOCK-UP DUTY SOLENOID

This solenoid is located in the transmission hydraulic control valve. Its duty ratio is controlled by
signals from the TCM. It then controls the lock-up control valve to provide smooth engagement and
disengagement of the lock-up clutch.

NF0078

(1) Lock-up duty solenoid

Q: 2-4 BRAKE DUTY SOLENOID

This solenoid is located in the transmission hydraulic control valve. Its duty ratio is controlled by
signals from the TCM. It modulates the 2-4 brake pressure when the 2-4 brake is operated, reduc-
ing shifting shocks.

NF0079

(1) 2-4 brake duty solenoid

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ELECTROHYDRAULIC CONTROL SYSTEM

Automatic Transmission

R: TRANSFER DUTY SOLENOID

This solenoid is located in the transfer hydraulic pressure control unit on the rear end of transmis-
sion case. Its duty ratio is controlled by signals from the TCM. It then controls the transfer clutch/
control valve to control the pressure applied to the transfer clutch.

NF0080

(1) Transfer duty solenoid

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

2. Transmission Control Module (TCM)

The TCM receives various sensor signals and determines the running conditions of the vehicle.
It then sends control signals to each solenoid according to the preset gearshift characteristic data,
lock-up operation data, and transfer clutch torque data (duty ratios).
A: CONTROL SYSTEM
Control item Input signal
Shift control Ordinary shift control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Engine speed
Inhibitor switch
Power switch
Kickdown switch
ABS-in-operation control ABS signal
Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Brake switch
Hydraulic oil temperature control ATF temperature sensor
Reverse inhibiting control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Inhibitor switch
Shift pattern (Base/Power) select control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Inhibitor switch
Hold control Inhibitor switch
Hold switch
Grade control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Brake switch
Inhibitor switch
Engine speed
Intake manifold pressure
Lock-up control Ordinary lock-up control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Engine speed
Inhibitor switch
Hold switch
Power switch
Smooth control Throttle position sensor
Hydraulic oil temperature control ATF temperature sensor

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

Control item Input signal

Oil pressure control Ordinary pressure control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Engine speed
Inhibitor switch
ATF temperature sensor
Shifting control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Engine speed
Torque converter turbine speed sensor
Inhibitor switch
ATF temperature sensor
Starting control Engine speed
ATF temperature sensor
Inhibitor switch
Learning control Shift solenoid A
Shift solenoid B
Rear vehicle speed sensor
Front vehicle speed sensor
Throttle position sensor
Torque converter turbine speed sensor
ATF temperature sensor
AWD transfer clutch control Ordinary transfer control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Inhibitor switch
ATF temperature sensor
FWD switch
1 range control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Inhibitor switch
Hold switch
Slip detection control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Steering control Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
ABS-in-operation control ABS signal
Throttle position sensor
Rear vehicle speed sensor
Front vehicle speed sensor
Brake switch

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

B: SYSTEM DIAGRAM

S3H0639A

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

C: SHIFT CONTROL
The TCM performs gear shifting control according to driving conditions by using the shift point
characteristic data stored in its memory. Appropriate solenoids are operated at the proper timing
corresponding to the shift pattern, throttle position, and vehicle speed for smooth shifting.
NOTE:
When the ATF temperature is below approximately 10°C (50°F), the gear cannot be shifted to the
4th speed.

NF0082

D The TCM activates both solenoids 1 and 2 in response to throttle and vehicle speed signals.
D Shift valves move in response to operation of the solenoids, supplying or interrupting the line
pressure to each clutch.
D A shift to each gear takes place according to ON-OFF operation of both the solenoids as indi-
cated in the table above.

NF0083

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

D: LOCK-UP CONTROL
D The TCM has pre-programmed lock-up clutch engagement and disengagement conditions for
each gear and shift pattern. In addition, it specifies engagement of the clutch whenever the 4th
gear is selected in the D range. The engagement and disengagement conditions are defined in
terms of the throttle valve position and vehicle speed.
D The TCM controls the operation of the lock-up clutch by means of the duty solenoid which in turn
controls the lock-up control valve as described below:

1. NON-LOCK-UP OPERATION
The duty solenoid allows the pilot pressure (supplied from the pilot valve) to be applied to the “dis-
engaging” end of the lock-up control valve spool. The lock-up control valve then opens the clutch
disengaging circuit port to allow the lock-up operating pressure (torque converter clutch regular
pressure) to build up in the circuit. On the other hand, the valve opens the clutch engaging circuit’s
port and allows the fluid in the circuit to flow to the ATF cooler, thus lowering the pressure in the
circuit. As a result, the lock-up clutch is disengaged due to difference in pressure between both
circuits.
This operation is performed for all the speed gears except the 4th gear of the D range.

2. LOCK-UP OPERATION
The duty solenoid allows the pilot pressure to be applied to the “engaging” end of the lock-up con-
trol valve spool. The lock-up control valve then opens the clutch engaging circuit’s port that com-
municates to the torque converter’s impeller chamber, allowing high pressure fluid to flow to the
lock-up clutch. The clutch then engages.
D The TCM controls the current to the duty solenoid by gradually changing the duty ratio. As a
result, the lock-up control valve also moves gradually, so the clutch engagement pressure in-
creases smoothly. This causes the lock-up clutch to become initially in a half-engaged state and
then in a fully engaged state, thus preventing shock during engagement.
This operation is performed for all the speed gears and always when the 4th gear is selected in
the D range.

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

E: LINE-PRESSURE CONTROL
D The oil pump delivery pressure (line pressure) is regulated to a constant pressure by the pilot
valve. This pressure is used as the pilot pressure for controlling spool valves.
D The pilot pressure applied to the pressure modifier valve is modulated by the line pressure duty
solenoid into the pressure modifier pressure.
D The pressure modifier valve is an auxiliary valve for the pressure regulator valve, and it creates
a signal pressure (pressure modifier pressure). The pressure modifier pressure is used to regulate
the line pressure to a level optimum for a particular driving condition.
D This pressure modifier pressure is applied to the pressure regulator valve which controls the oil
pump delivery pressure.
D The pressure modifier pressure from the pressure modifier valve is cushioned by the pressure
modifier accumulator to remove pulsation of the pressure.

NF0084

(1) Relief valve (7) Filter (13) Pressure regulator valve

(2) Pilot valve (8) Accumulator (14) Oil pump
(3) Line pressure (9) Pressure modifier valve (15) ON
(4) Pilot pressure (10) To ATF cooler circuit (16) OFF
(5) Filter (11) Accumulator
(6) Line pressure duty solenoid (12) From R range pressure circuit

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

F: LINE-PRESSURE CONTROL DURING SHIFTING

The line pressure which engages shift clutches to create 1st to 4th speeds is controlled by the TCM
to meet varying operating conditions.
During gear shifting, the TCM decreases the line pressure to a level that matches the selected gear
in order to minimize shifting shock loads.

NF0085

During gear shifting, the TCM controls the line pressure as follows:
D The TCM receives signals such as throttle position signal and accelerator pedal speed signal.
Based on these input signals, it issues a control signal to the line pressure duty solenoid.
D The pressure from the line pressure duty solenoid (line pressure duty pressure) is converted by
the pressure modifier valve into a modifier pressure, and the modifier pressure is applied to the
pressure regulator valve.
D The pressure regulator valve adjusts the oil-pump-generated line pressure according to the
modifier pressure to make the line pressure matched to the driving condition.

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

G: SHIFT PATTERN SELECTION CONTROL

1. POWER PATTERN CONTROL
Shift pattern is selectable; a Base pattern suitable for ordinary economy running and a Power pat-
tern suitable for climbing uphill rapid acceleration are available.
In the Power pattern, the downshift point and upshift point are set higher than those of the Base
pattern.
When the Power pattern is selected, the POWER indicator light in the combination meter lights up.
Changeover from Base to Changeover from Power to
Selector lever position POWER indicator light
Power pattern Base pattern
D, 3, and 2 ranges Occurs when Power switch is Occurs when Power switch is D Base pattern: OFF
ON OFF D Power pattern: ON

The Power pattern selection is possible in the D, 3 or 2 range and only when the hold switch is in
the OFF position because the hold pattern control takes precedence over the Power pattern con-
trol.

NF0086

2. HOLD PATTERN CONTROL

The hold pattern control enables maintaining the transmission in the selected gear (in the 2, 3, and
D ranges) or lower when going up or down steep slopes, running on sand, mad or slippery sur-
faces.
When the hold pattern is selected, the HOLD indicator light in the combination meter lights up.
Selector position (hold switch ON) Shift pattern
D range 2nd à 3rd à 4th
3 range 2nd à 3rd ä 4th
2 range 2nd ä 3rd ä 4th

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

H: GRADE CONTROL
While the vehicle is driving up a hill, the gear is fixed to the 3rd to avoid repeated gear shift between
the 3rd and 4th gears.
When the vehicle is descending a steep slope at a speed of approximately 80 km/hour (50 miles/
hour), a 4th to 3rd downshift occurs automatically when the brake pedal is depressed.
This gearshift control is cancelled when the accelerator pedal is depressed.
The TCM performs these controls based mainly on the throttle opening, engine speed and vehicle
speed.

NF0087

NF0088

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

I: LEARNING CONTROL
The TCM has a learning control function with which it can adapt gear shift timing optimally to the
current vehicle conditions by updating correction factors in the memory.
For this reason, gear shift shock may become larger after the power supply is interrupted (discon-
nection of battery, flat battery, etc.) or immediately after the ATF is replaced.
Larger gear shift shock after power supply interruption occurs because the correction data is reset
to those for the new vehicle condition.
The TCM starts learning function again as soon as the power supply is restored. After driving for
a while, therefore, the transmission will become able to make gear shifts at the optimum timing.
Larger shift shock immediately after ATF change is caused by change in friction characteristics
of the transmission internal parts. Also in this case, the transmission recovers shockless gear shift-
ing after driving for a while.

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

J: REVERSE INHIBITION CONTROL

This control prevents the transmission from shifting into the reverse gear when the select lever is
accidentally placed in the R position, thus protecting the components such as reverse clutch from
being damaged.
If the selector lever is moved to the R position during driving at a speed faster than the predeter-
mined speed, the low clutch timing solenoid is energized. Then, the pilot pressure is supplied to
the reverse inhibitor valve. This causes the reverse inhibitor valve to move downward, closing the
low & reverse brake port.
In this condition, the low & reverse brake does not engage since the ATF flowing from the manual
valve is blocked by the reverse inhibitor valve.
As a result, the transmission is put into the neutral state, and the shifting into the reverse gear is
inhibited.

NF0089

(1) Line pressure (6) Manual valve (P range) (11) Low & reverse brake (Release)
(2) Pilot pressure (7) Drain (12) Low clutch
(3) 1st reducing valve (8) Shift valve B (13) 2-4 brake
(4) Shift valve A (9) Low clutch timing solenoid (14) Reverse clutch
(5) ON (10) Reverse inhibitor valve (15) High clutch

AT-24

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

K: AWD TRANSFER CLUTCH CONTROL

Control item Type of control Gear position Remarks

Regulates transfer clutch pressure in re-

1 Basic control sponse to throttle position and vehicle 1st thru 4th and reverse
speed.

NF0361
Increases transfer clutch pressure above
2 1 range control 1st –
basic control pressure
Increases transfer clutch pressure to the Release:
3 Slip control same level as in the 1 range immediately 1st thru 4th and reverse When running faster than the set ve-
after a slip is detected. hicle speed with fully closed throttle
Decreases transfer clutch pressure upon
4 Turning control 1st thru 4th and reverse –
detection of a turn.
Regulates to the specified transfer clutch
5 ABS control pressure quickly when the ABS signal is 1st thru 4th and reverse –
input.
Regulates to the specified transfer clutch
P and N range con-
6 pressure quickly when shifted to the P or N P and N –
trol
range.

B3H0315C

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

L: TRANSFER CONTROL
The transfer hydraulic pressure control unit includes a valve body attached to the side of the exten-
sion case through a gasket and separator plate.
The pressurized fluids for the transfer hydraulic pressure control (line pressure and pilot pressure)
are supplied from the oil pump by way of the passages formed in the transmission case and then
the passages in the extension case that lead to the hydraulic circuit in the transfer valve body.
The line pressure is regulated by the transfer control valve whose opening is controlled by the
transfer pressure created by the transfer duty solenoid.
D The transfer duty solenoid is controlled by the TCM. The TCM changes the solenoid controlling
duty ratio according to the driving conditions.
D The transfer duty solenoid creates the transfer pressure from the pilot pressure. The transfer
pressure is applied to the transfer control valve and adjusts the valve’s opening.
D The line pressure directly led to the transfer control valve, on the other hand, is regulated by the
transfer control valve and becomes the transfer clutch pressure.
D The transfer clutch pressure is applied to the transfer clutch and engages the clutch to a con-
trolled degree.
In this way, the degree of transfer clutch engagement is varied so that optimum torque is distrib-
uted to the rear wheels according to vehicle driving conditions.

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TRANSMISSION CONTROL MODULE (TCM)

Automatic Transmission

NF0091

(1) Transfer control valve (4) Transfer pressure (7) Line pressure
(2) Transfer clutch pressure (5) Filter (8) Oil pump
(3) Transfer duty solenoid (6) Pilot pressure (9) Control valve

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ON-BOARD DIAGNOSTICS SYSTEM

Automatic Transmission

3. On-board Diagnostics System

A: FUNCTION
The on-board diagnostics system detects and stores in the form of a code a fault that has occurred
in any of the following input and output signal systems.
Rear vehicle speed sensor Transfer duty solenoid Low clutch timing solenoid
Front vehicle speed sensor ATF temperature sensor Torque converter turbine speed sensor
Throttle position sensor Engine speed signal circuit –
Shift solenoid 1 Line pressure duty solenoid –
Shift solenoid 2 AT load signal circuit –
2-4 brake timing solenoid Torque control signal circuit –
Lock-up duty solenoid 2-4 brake duty solenoid –

If a fault has been detected, the system tells the fault by causing the POWER indicator light to oper-
ate as follows:
D Repeated flashing at 4 Hz frequency ...Errors such as battery trouble
D Repeated flashing at 2 Hz frequency ...No faults in the system
D Flashing at different intervals and frequencies ...Diagnostic trouble codes of corresponding
faults
D Continued illumination of light ...Fault in inhibitor switch, idle switch, or wiring

B: OPERATION OF POWER INDICATOR LIGHT

On starting the engine, the POWER indicator light illuminates and then goes out as shown in the
“Normal” diagram below.
If any problem exists, the light continues flashing as shown in the “Abnormal” diagram below.

NF0092

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ON-BOARD DIAGNOSTICS SYSTEM

Automatic Transmission

C: DIAGNOSTIC TROUBLE CODE

Code Faulty component
11 Engine speed signal circuit
23 Mass air flow signal (Turbo model)
27 ATF temperature sensor
31 Throttle position sensor
33 Front vehicle speed sensor
36 Torque converter turbine speed sensor
38 Torque control signal circuit
45 Intake manifold pressure signal circuit (Non-turbo model)
71 Shift solenoid 1
72 Shift solenoid 2
73 Low clutch timing solenoid
74 2-4 brake timing solenoid
75 Line pressure duty solenoid
76 2-4 brake duty solenoid
77 Lock-up duty solenoid
79 Transfer duty solenoid
93 Rear vehicle speed sensor

D: SELECT MONITOR
Various sensor and switch data as well as diagnostic trouble codes for faults that are currently
present and occurred in the past can be monitored by connecting the select monitor to the select
monitor terminal located under the instrument panel.

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FAIL-SAFE FUNCTION
Automatic Transmission

4. Fail-safe Function
The fail-safe control function ensures minimum level of driveability even if a fault should occur in
the vehicle speed sensors, throttle position sensor, inhibitor switch, or any of the solenoids.
D FRONT AND REAR VEHICLE SPEED SENSORS
A dual speed-sensing system is used. The speed signal is taken from the transmission (by the out-
put shaft speed sensor). Even if one sensor system fails, the vehicle can be controlled normally
with the other normally operating sensor system.
If both the front and rear vehicle speed sensors become faulty, the vehicle is made to operate only
in the 1st and 3rd speeds.
D THROTTLE POSITION SENSOR
If the throttle position sensor becomes faulty, the throttle opening is fixed at the predetermined
angle.
D INHIBITOR SWITCH
If the TCM receives different signals simultaneously from a faulty inhibitor switch, it selects a range
in the following priority:
D > N (P) > R > 3 > 2 > 1 >
D SHIFT SOLENOID 1 AND 2
If a fault occurs in either of solenoids 1 and 2, both the solenoids are de-energized, and the gear
is held in the 3rd.
If both the solenoids should fail, the TCM invariably selects and keeps the 3rd gear.
D LINE PRESSURE DUTY SOLENOID
If the line pressure duty solenoid fails, the solenoid is de-energized and the line pressure is raised
to the maximum to enable the vehicle to operate.
In this condition, the usable gears are limited to the 1st and 3rd.
D LOCK-UP DUTY SOLENOID
If the lock-up duty solenoid fails, the solenoid is de-energized and the lock-up clutch is disen-
gaged.
D TRANSFER DUTY SOLENOID
When the transfer duty solenoid becomes faulty, it is de-energized. This causes maximum oil pres-
sure to be applied to the transfer clutch so that the power is always transmitted to the rear axle
(direct-coupled AWD condition).
D 2-4 BRAKE DUTY SOLENOID
If a fault occurs in the 2-4 brake duty solenoid, the solenoid is de-energized and the usable gears
are limited to the 1st and 3rd.
D LOW-CLUTCH TIMING SOLENOID
If a fault occurs in the low clutch timing solenoid, the solenoid is de-energized and the usable
gears are limited to the 1st and 3rd.

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FAIL-SAFE FUNCTION
Automatic Transmission

D 2-4 BRAKE TIMING SOLENOID

If a fault occurs in the 2-4 brake timing solenoid, the solenoid is de-energized and the usable gears
are limited to the 1st and 3rd.
D TORQUE CONVERTOR TURBINE SPEED SENSOR
If a fault occurs in the torque converter turbine speed sensor, the usable gears are limited to the
1st and 3rd.

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TRANSMISSION MOUNTING
Automatic Transmission

5. Transmission Mounting

S2H0004C

(1) Pitching stopper

(2) Cushion rubber
(3) Cross member

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MANUAL TRANSMISSION
AND DIFFERENTIAL MT
Page
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Auxiliary Transmission Gears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Reverse Check Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Center Differential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5. Oil pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6. Transmission Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

MT

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GENERAL
Manual Transmission and Differential

1. General
A: SINGLE-RANGE MODEL
The single-range manual transmission is of a full-time all-wheel-drive design integrating a trans-
mission assembly, front differential, and transfer gear assembly with center differential into a single
unit. The transmission creates five forward speeds and one reverse using the corresponding
gears all provided with inertia lock-key type synchronizers.
The transmission and front differential are housed in an aluminum case which is split into right and
left halves and constitutes also a clutch housing. Located at the rear and joined each other are
the transfer case and extension case which house the transfer gears and center differential as well
as part of the transmission assembly.
The major features of the transmission are as follows:
D The forward speed gears are helical gears featuring high tooth face strength, large tooth contact
areas, and quiet operation.
D Reversing rotation is achieved by making a slidable reverse idler gear engage with both the re-
verse drive gear on the mainshaft and the reverse driven gear integral with the 1st-2nd synchroniz-
er hub on the drive pinion shaft.
The center differential compensates for the difference in front and rear axle speeds. It consists of
a bevel gear set and a viscous coupling located at its rear end which are housed in a single case.
The center differential, together with a pair of transfer gears, transmits the power from the transmis-
sion to the drive pinion shaft (front wheel drive shaft) and the rear drive shaft. The viscous coupling
functions as a differential-action-control element.

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GENERAL
Manual Transmission and Differential

B3H1853A

(1) Mainshaft (7) Extension case (13) 1st driven gear

(2) 3rd drive gear (8) Transfer drive gear (14) Drive pinion shaft
(3) 4th drive gear (9) Viscous coupling (15) Front differential assembly
(4) 5th drive gear (10) Center differential assembly
(5) Transfer case (11) Driven shaft (countershaft)
(6) Transfer driven gear (12) 2nd driven gear

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GENERAL
Manual Transmission and Differential

B: DUAL-RANGE MODEL
The dual-range manual transmission is of a full-time all-wheel-drive design integrating a transmis-
sion assembly, front differential, and transfer gear assembly with center differential into a single
unit. The transmission creates five forward speeds and one reverse using the corresponding
gears all provided with inertia lock-key type synchronizers.
The transmission and front differential are housed in an aluminum case which is split into right and
left halves and constitutes also a clutch housing. Located at the rear and joined each other are
the transfer case and extension case which house the transfer gears and center differential as well
as part of the transmission assembly.
The major features of the transmission are as follows:
D The forward speed gears are helical gears featuring high tooth face strength, large tooth contact
areas, and quiet operation.
D Reversing rotation is achieved by making a slidable reverse idler gear engage with both the re-
verse drive gear on the mainshaft and the reverse driven gear integral with the 1st-2nd synchroniz-
er hub on the drive pinion shaft.
D The 1st driven gear on the drive pinion shaft has a subgear which helps reduce noise during
engagement.
The center differential compensates for the difference in front and rear axle speeds. It consists of
a bevel gear set and a viscous coupling located at its rear end which are housed in a single case.
The center differential, together with a pair of transfer gears, transmits the power from the transmis-
sion to the drive pinion shaft (front wheel drive shaft) and the rear drive shaft. The viscous coupling
functions as a differential-action-control element.
On the part just above the front differential of the input shaft, there are auxiliary transmission gears
of synchromesh design. They provides a dual-range function that allows the driver to select “high”
or “low” range as desired. Switching of the range is possible even during driving if the clutch pedal
is depressed and then the range selector lever is moved.

MT-4

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GENERAL
Manual Transmission and Differential

B3H2091A

(1) Input shaft (7) Transfer driven gear (13) Driven shaft (countershaft)
(2) Auxiliary transmission gears (8) Extension case (14) 3rd driven gear
(3) 3rd drive gear (9) Transfer drive gear (15) 2nd driven gear
(4) 4th drive gear (10) Center differential assembly (16) 1st driven gear
(5) 5th drive gear (11) Viscous coupling (17) 1st driven sub-gear
(6) Transfer case (12) Drive pinion shaft (18) Front differential assembly

MT-5

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AUXILIARY TRANSMISSION GEARS

Manual Transmission and Differential

2. Auxiliary Transmission Gears

The auxiliary transmission gear mechanism consists of the input high gear (integral part of the in-
put shaft), input low gear, counter gear and Hi-Lo coupling sleeve.
D High range
The splines of the Hi-Lo coupling sleeve are in mesh with the splines of the input high gear. The
input high gear and the main shaft are directly connected and rotate at the same speed.
The power flow in this range is as follows: input shaft ! input high gear ! Hi-Lo coupling sleeve
! Hi-Lo synchronizer hub ! main shaft.
D Low range
The splines on the Hi-Lo coupling sleeve are in mesh with the splines of the input low gear. The
input low gear and the main shaft rotate as a unit.
The power flow in this range is as follows: input shaft ! counter gear ! input low gear ! Hi-Lo
coupling sleeve and hub ! main shaft.

S3H0216A

(1) Input shaft (with integrally formed input high gear) (4) Input low gear
(2) Hi-Lo coupling sleeve (5) Main shaft
(3) Counter gear

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AUXILIARY TRANSMISSION GEARS

Manual Transmission and Differential

MEMO

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REVERSE CHECK MECHANISM

Manual Transmission and Differential

3. Reverse Check Mechanism

Located in the transfer case, the reverse check mechanism prevents a direct 5th-to-reverse shift
by using a selector arm and cam combination which allows the gear to be shifted into the reverse
only after it has been returned once into the neutral.

A: CONSTRUCTION
The construction of the reverse check mechanism is as shown in the drawing on the opposing
page.
The reverse check sleeve is bolted to the transfer case and houses the mechanism’s main compo-
nents.
The reverse accent shaft is slidable inside the reverse check sleeve and its smaller-diameter end
is fitted with the reverse check cam. The cam is rotatable and axially movable on the shaft but its
leftward movement is restricted by a step formed on the sleeve’s inner wall.
The reverse accent shaft has hollows in both ends. In the left end hollow are the 1st return spring
and its cap and in the right end hollow is the reverse return spring which pushes the shaft leftward.
Around the check cam is the reverse check spring whose left end applies simultaneous leftward
and rotational forces to the cam.
Both the reverse check spring and reverse return spring are retained at their right ends by the re-
verse check plate which is held in place by the snap ring.
The reverse accent shaft has a V-groove in which the detent ball is pressed by the reverse accent
spring fitted through the hole in the reverse check sleeve.
The reverse check sleeve and reverse accent shaft have a slot and a notch at their bottoms, re-
spectively, and the selector arm is inserted in the notch through the slot.

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REVERSE CHECK MECHANISM

Manual Transmission and Differential

B3H1007A

(1) Select adjust shim (6) Reverse check cam (11) Selector arm
(2) Detent ball (7) Reverse return spring (12) Spring cap
(3) Reverse accent spring (8) Reverse check spring (13) 1st return spring
(4) Reverse check sleeve (9) Snap ring (14) O-ring
(5) Reverse accent shaft (10) Reverse check plate

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REVERSE CHECK MECHANISM

Manual Transmission and Differential

B: OPERATION
The drawing below shows the state of the reverse check mechanism when the selector arm is in
the neutral position. The 1st and 2nd gears will be selected if the selector arm is moved leftward
from this point to a stop and then turned in either way. A rightward movement of the arm to a stop
will enable selection of the 5th and reverse gears. In the neutral position, the selector arm receives
a rightward force (force toward the 5th and reverse gear side) from the 1st return spring and a
leftward force (force toward the 1st and 2nd gear side) from the reverse return spring to stay in
that position.
The following explanation describes how the selector arm and reverse check mechanism operate
when the driver selects the 5th gear and then selects the reverse gear.

B3H1007B

(1) 1st return spring (3) Reverse accent shaft (5) 5th and reverse gear side
(2) Reverse check sleeve (4) Reverse return spring (6) 1st and 2nd gear side

MT-10

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REVERSE CHECK MECHANISM

Manual Transmission and Differential

1. WHEN SELECTOR ARM IS MOVED TOWARD 5TH AND REVERSE GEAR SIDE
The selector arm moves rightward while pushing both the reverse accent shaft and reverse check
cam simultaneously.

B3H1008B

(1) Reverse check sleeve (3) Reverse check cam (5) Neutral position
(2) Reverse accent shaft (4) Selector arm

2. WHEN SHIFT IS MADE TO 5TH GEAR

The selector arm is turned toward the 5th gear selection direction. When the arm clears the edge
of the reverse check cam as it turns, the cam becomes free of the selector arm’s pressure and
returns to its original position by the force of the reverse check spring.

B3H1009A

(1) Reverse check sleeve (3) Reverse check cam (5) Reverse check spring
(2) Reverse accent shaft (4) Selector arm

MT-11

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REVERSE CHECK MECHANISM

Manual Transmission and Differential

3. WHEN A SHIFT FROM 5TH TO REVERSE IS ATTEMPTED

The selector arm turns toward the reverse gear while pushing the reverse accent shaft rightward
and the reverse check cam counterclockwise (as viewed in the direction of arrows A).
The reverse check cam, however, stops to rotate at a point where its stopper hits against the re-
verse check plate (this point corresponds to the neutral position in terms of the angle) and pre-
vents the selector arm from moving toward the reverse gear selection direction. The selector arm
is then axially pushed to the neutral position by the reverse accent shaft which is given a leftward
force by the reverse return spring.

Position at
“5th → Neutral position”

A–A
5th → Neutral position
B3H2118A

(1) Reverse check sleeve (5) Reverse check plate

(2) Reverse accent shaft (6) Snap ring
(3) Reverse check cam (7) Selector arm
(4) Reverse return spring

MT-12

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REVERSE CHECK MECHANISM

Manual Transmission and Differential

4. WHEN A SHIFT TO REVERSE IS MADE AFTER RETURN OF SELECTOR ARM TO NEU-

TRAL
As the ends of the reverse accent shaft and the reverse check cam are on the same plane, the
selector arm now can turn toward the reverse gear selection direction after pushing leftward both
the shaft and cam simultaneously.

B3H1011A

(1) Reverse check sleeve (3) Reverse check cam

(2) Reverse accent shaft (4) Selector arm

MT-13

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CENTER DIFFERENTIAL
Manual Transmission and Differential

4. Center Differential
A: CONSTRUCTION
The center differential consists of a set of bevel gears and a viscous coupling.
The center differential has the following two functions: distributing the engine torque to the front
and rear wheel drive shafts and absorbing the difference in rotating speed between the front and
rear wheels.
The engine torque enters the center differential case from the transmission’s driven shaft. The
torque is then distributed through the bevel gear set directly to the drive pinion shaft and via the
transfer drive and driven gears to the rear drive shaft.
The viscous coupling limits the bevel gear set’s differential action when either front or rear wheels
spin so that adequate torques are transmitted to the front and rear wheels and proper traction is
obtained.

B3H1854A

(1) Transfer driven gear (4) Center differential assembly (with viscous coupling)
(2) Transfer drive gear (5) Drive pinion shaft
(3) Viscous coupling (6) Driven shaft

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CENTER DIFFERENTIAL
Manual Transmission and Differential

B: MECHANISM OF VISCOUS COUPLING

The viscous coupling consists of a number of alternately arranged inner and outer plates and air-
and-silicone oil mixture filled into a sealed space that is formed by the center differential case and
the rear side gear of the differential gear set. The inner plates have their inner perimeters splined
to the side gear and the outer plates have their outer perimeters splined to the center differential
case. The outer plates are held apart by spacer rings. There are no spacer rings between the inner
rings, so the inner rings are movable slightly in axial directions. X-section rings are used to prevent
leakage of silicone oil which would otherwise occur if the oil is pressurized due to large difference
in front and rear axle speeds.

B3H1002B

(1) X-section ring (5) Inner plate

(2) O-ring (6) X-section ring
(3) Spacer ring (7) Side gear (rear)
(4) Outer plate

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CENTER DIFFERENTIAL
Manual Transmission and Differential

1. TORQUE CHARACTERISTICS
When a speed difference occurs between the center differential case and the rear side gear, a
shear force is generated in the silicone oil placed between the outer and inner plates. The torque
is then transmitted by the silicone oil between the center differential case and the rear side gear.
The greater the speed difference, the greater the shear force generated in the silicone oil. The rela-
tionship between the torque transmission and the speed difference is shown in the figure below.
As can be seen from the figure, the smaller the speed difference, the smaller the torque transmis-
sion and the differential action.

Speed difference

B3H1723B

2. HUMP PHENOMENON
Silicone oil is heated and expanded as differential action continues. This causes the pressure of
air inside the viscous coupling to increase and the pressure of oil between plates to decrease. As
a result, the inner and outer plates are pushed together. This direct plate-to-plate contact causes
a non-viscous operation to occur, and this phenomenon is called “hump”.
The hump eliminates the rotating speed difference between the center differential case and the
rear side gear (or locks the differential), so soon after it has occurred, the internal pressure and
temperature drop. The viscous coupling then returns to the normal shear torque transmitting op-
eration. (The hump phenomenon does not occur under normal operating conditions.)

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CENTER DIFFERENTIAL
Manual Transmission and Differential

C: FUNCTION
When there is no speed difference between the front and rear wheels, the center differential deliv-
ers the engine torque to the front and rear wheels at a ratio of 50:50.
When a rotating speed difference occurs between the front and rear wheels, the center differential
operates to absorb it in a controlled way by the function of the viscous coupling.

1. DURING NORMAL DRIVING

During straight-line driving on a flat road at a constant speed, all the four wheels rotate at the same
speed. The center differential delivers engine torque evenly to the front and rear drive axles. The
viscous coupling does not generate shear torque because there is no relative movements be-
tween the inner and outer plates.

B3H1003B

(1) Engine torque (A) To front differential (B) To rear differential

2. DURING TURNS AT LOW SPEEDS

During turns at low speeds, rotating speed difference occurs between the front and rear wheels,
as well as between the left and right wheels. More particularly, the front wheels rotate faster than
the rear wheels. The center differential then acts to absorb the speed difference to enable smooth
driving.
Although the speed difference is small under this condition, operation of the viscous coupling
causes more torque to be transmitted to the rear than to the front.

B3H1004

MT-17

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CENTER DIFFERENTIAL
Manual Transmission and Differential

3. DRIVING ON ROUGH OR SLIPPERY ROADS

D When front wheels are on a slippery surface
When the front wheels begin to spin, the resulting speed difference between the front and rear
drive shafts causes the viscous coupling to generate significant amount of shear torque. As a re-
sult, the torque distributed to the rear wheels becomes much larger than that distributed to the
spinning front wheels. The traction and driving stability are thus ensured on a rough or slippery
road.

B3H1006

D When rear wheels are on a slippery surface

When the vehicle is accelerated quickly from a standing start with the rear wheels on a slippery
surface, the distribution of the vehicle weight on the front and rear wheels changes and the rear
wheels start spinning. Due to the resulting speed difference between the front and rear drive
shafts, the viscous coupling generates a significant amount of shear torque, now in the direction
opposite to that generated when the front wheels are on a slippery surface. As a result, the torque
distributed to the front wheels becomes much larger than that distributed to the rear wheels.

B3H1005

MT-18

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OIL PUMP
Manual Transmission and Differential

5. Oil Pump
A: CONSTRUCTION
The Turbo model’s manual transmission is provided with an oil pump at the rear end of the exten-
sion case.
After being sucked by the oil pump through the oil strainer in the transfer, the transmission gear
oil is sent to the oil cooler in the radiator through the outlet pipe in the extension case. The transmis-
sion gear oil cooled down there is then routed back to the transmission case through the inlet pipe
in the transmission case.

S3H0614A

(1) Transmission case (9) Oil pump shaft (17) Ball bearing
(2) Inlet pipe (10) Inner rotor (18) Snap ring
(3) Outlet pipe (11) Outer rotor (19) Washer
(4) Oil seal (12) Relief valve (20) Taper roller bearing
(5) Dust cover (13) Return spring (21) Transfer drive gear
(6) Bracket (14) Extension case (22) Taper roller bearing
(7) Oil pump cover (15) Oil strainer (23) Straight pin
(8) O-ring (16) Transfer driven gear

MT-19

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OIL PUMP
Manual Transmission and Differential

B: FUNCTION
The oil pump is a trochoid type oil pump and is driven together with the transfer driven gear.
The oil pump is provided with a relief valve. This valve opens when the transmission gear oil tem-
perature rises beyond the predetermined level, allowing some part of the transmission gear oil that
entered the discharge chamber to flow back into the suction chamber through the passage in it
to stabilize the oil pressure.

S3H0233B

(1) Discharge chamber

(2) Oil strainer
(3) Suction chamber
(4) Relief valve

MT-20

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TRANSMISSION MOUNTING
Manual Transmission and Differential

6. Transmission Mounting
The bolt hole in the transmission end of the pitching stopper is a slot so that the bolt position can
be adjusted in it.

S2H0003C

(1) Pitching stopper (2) Cushion rubber (3) Cross member

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TRANSMISSION MOUNTING
Manual Transmission and Differential

MEMO

MT-22

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CLUTCH CL
Page
1. Clutch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Flywheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Hydraulic Clutch Pedal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

CL

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CLUTCH
Clutch

1. Clutch
A: OUTLINE
D All the models use a hydraulic clutch control system which is appropriate for increased load to
the clutch.
D The hydraulic control system includes a master cylinder which generates a hydraulic pressure
as the clutch pedal is depressed and a slave cylinder which receives the hydraulic pressure and
activates the clutch release fork to disengage the clutch.
D The clutch mechanism is of a diaphragm spring design which is advantageous in that wear of
the clutch disc facing causes only small variation in the push load of the pressure plate.

B: OPERATION
Applying foot pressure to the clutch pedal moves the release lever. This causes the release bear-
ing to slide on the guide, pressing the center of the diaphragm spring. The spring is warped and
the force having pressed the pressure plate is lost. As a result, the flywheel, clutch disc and pres-
sure plate are disengaged, disconnecting the driving power.
The push type clutch has the point of action at the tips of the diaphragm spring fingers, through
which the pressure plate is pressed to the clutch disc. When the power transmission is to be inter-
rupted, the diaphragm spring is forced to warp using the pivots established on the inward side
of the spring finger tips (on the principle of the lever and fulcrum) to disengage the pressure plate
from the clutch disc.

CL-2

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CLUTCH
Clutch

C: CROSS SECTIONAL VIEW

1. NON-TURBO MODEL

S2H0888A
(1) Operating cylinder (3) Release bearing (5) Transmission main shaft
(2) Release lever (4) Clutch cover (6) Clutch disc

CL-3

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CLUTCH
Clutch

2. TURBO MODEL

NF0211

(1) Spring bracket (5) Flywheel (9) Ball bearing

(2) Spring (6) Clutch cover (10) Release bearing
(3) Release lever (7) Clutch disc
(4) Operating cylinder (8) Transmission main shaft

CL-4

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CLUTCH
Clutch

MEMO

CL-5

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FLYWHEEL
Clutch

2. Flywheel
The flywheel is of a flexible type, consisting of a drive plate, reinforcement, and mass flywheel.
This flywheel helps reduce vibration and noise since it transmits the engine power from the crank-
shaft to the clutch disc through the drive plate and mass flywheel.

CL-6

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FLYWHEEL
Clutch

S2H0888B

(1) Ring gear (3) Ball bearing (5) Mass flywheel

(2) Drive plate (4) Reinforcement

CL-7

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HYDRAULIC CLUTCH PEDAL SYSTEM

Clutch

3. Hydraulic Clutch Pedal System

A: CONSTRUCTION
D The hydraulic clutch pedal is connected to the master cylinder via a rod.
D The clutch pedal and brake pedal are mounted on the same bracket (LHD model only).

D LHD model

S4H0316B

(1) Clutch pedal

(2) Brake pedal
(3) Brake and clutch pedal bracket
(4) Rod
(5) Lever

CL-8

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HYDRAULIC CLUTCH PEDAL SYSTEM

Clutch

D RHD model

(1)

S4H0237A

(1) Clutch pedal

CL-9

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HYDRAULIC CLUTCH PEDAL SYSTEM

Clutch

D The clutch pedal has a mechanism that reduces the initial force required to depress the clutch
pedal.
D A hill holder control cable is connected to the clutch pedal.

S4H0238B

(1) Initial pedal effort reducing mechanism

(2) PHV cable (Hill holder)
(3) Clutch pedal

B: OPERATION
The clutch pedal used with the hydraulic clutch control system is similar to that for a mechanical
clutch control system except that it has a spring that returns it to the original position.

CL-10

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FRONT SUSPENSION FS
Page
1. Front Suspension ....................................................................2

FS

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FRONT SUSPENSION
Front Suspension

1. Front Suspension
A: OUTLINE
The front suspension is a strut-type independent suspension, with cylindrical double-acting, oil-
filled dampers and coil springs. The top of each strut assembly is attached to the body through
a rubber cushion. Used in combination with other rubber cushions, this rubber cushion effectively
insulate vibration and shock and thus improves ride comfort. This type also maintains a wide dis-
tance between the upper and lower supporting points and makes adjustment of the caster unnec-
essary.
The transverse link is an “L” shaped arm design to increase steering stability and reduce road
noise. The transverse link has a maintenance-free ball joint fitted by a castle nut at its outer end.
The front of the link’s inner end is fitted to the front crossmember through a rubber cushion and
the rear of the inner end is bolted to the vehicle body through a fluid-filled bushing.
The front crossmember is bolted to the vehicle body.
The stabilizer is attached to the front crossmember through rubber cushions and its right and left
ends are connected to the stabilizer links through rubber bushings.
The lower end of the stabilizer link is connected to the transverse link through rubber bushings.
A camber angle adjustment mechanism, which uses eccentric bolts, is provided at the joint of the
damper strut and axle housing.

FS-2

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FRONT SUSPENSION
Front Suspension

H4H1040B

(1) Strut mount (4) Stabilizer link

(2) Strut (5) Stabilizer
(3) Transverse link (6) Front crossmember

FS-3

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FRONT SUSPENSION
Front Suspension

MEMO

FS-4

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REAR SUSPENSION RS
Page
1. Rear Suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Self-leveling Rear Suspension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

RS

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REAR SUSPENSION
Rear Suspension

1. Rear Suspension
A: OUTLINE
The rear suspension is an independent, dual link strut type. On each side, the rear suspension
consists of two parallel lateral links, a trailing link, and strut assemblies. The strut assembly con-
sists of a cylindrical double-acting oil damper and coil spring.
The components of this suspension are designed for optimal response to vertical, lateral and lon-
gitudinal loads transmitted from the tires. Thus, riding comfort and steering stability are substan-
tially enhanced.
D Longitudinal loads act on the trailing link.
D Vertical loads act on the coil spring, strut and rubber mount (which is located on the top of strut).
D Lateral loads act on the two lateral links.
The crossmember is installed on the body frame via bushings.
The stabilizer that extends to the rear of the crossmember, is connected to the body frame via a
bracket and to the rear lateral link on the wheel side via stabilizer link.

H4H1039B

(1) Strut mount (5) Front lateral link

(2) Strut (6) Rear lateral link
(3) Stabilizer (7) Rear crossmember
(4) Trailing link

RS-2

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SELF-LEVELING REAR SUSPENSION

Rear Suspension

2. Self-leveling Rear Suspension

A: OUTLINE
The self-leveling rear suspension is a vehicle height adjusting system which requires no external
source of power such as hydraulic pump and compressor nor uses the vehicle height sensor and
controller. Utilizing vehicle’s vertical movements during driving, this suspension pumps up oil to
increase the pressure inside the rear strut, keeping the vehicle at a constant height.
D When the vehicle height is at the normal level, the pumping action does not take place and this
suspension operates as an ordinary suspension.
D If the vehicle height is decreased by loading, the pumping action takes place during driving,
which increases the rear strut internal pressure. After being driven 2 to 3 km (1.2 to 1.9 miles), the
vehicle will resume its original height.
D If the vehicle height is increased after unloading cargos from the vehicle, the pressure inside
the rear strut is decreased and the vehicle will return to the original height after driving 400 to 500
m (0.24 to 0.3 miles).
NOTE:
The driving distance required to resume the original height varies depending on the road surface
conditions.

S4H0196A

(1) Vehicle height returned to original level after driving 2 to 3 km (1.2 to 1.9 miles)
(2) Vehicle at reduced height before driving.

RS-3

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SELF-LEVELING REAR SUSPENSION

Rear Suspension

B: OPERATION
1. WHEN THE VEHICLE HEIGHT IS AT THE NORMAL LEVEL
D The relief orifice provided in the pump rod is closed by the pump tube. Since the flat section of
the pump rod overlaps the larger-diameter-portion of the pump tube, the oil flows from the cham-
ber in the pump into the chamber in the cylinder.
D When the piston rod is extended from the cylinder, the volume of the chamber in the pump is
increased, allowing the oil to flow from the chamber in the cylinder to the chamber in the pump
along the larger-diameter-portion of the pump tube and the flat section of the pump rod. (At that
time, no oil is sucked from the oil tank.)
D When the piston rod is retracted into the cylinder, the oil sucked into the chamber in the pump
flows back into the chamber in the cylinder through the space between the larger-diameter-portion
of the pump tube and the flat section of the rod.
D As described above, the oil flows in and out between the chambers in the cylinder and pump,
so no oil is sucked from the oil tank when the vehicle is at the normal height. Therefore, no pressure
builds up inside the chamber in the cylinder. The overlap between the flat section of the pump rod
and the larger-diameter-portion of the pump tube serves as a neutral zone.

RS-4

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SELF-LEVELING REAR SUSPENSION

Rear Suspension

S4H0197A

(1) Piston rod (10) Check valve of pump tube

(2) Chamber in pump (11) Pump tube
(3) Check valve of pump rod (12) Flat section of pump rod
(4) Reserve gas chamber (13) Neutral zone
(5) Relief orifice (14) Chamber in cylinder
(6) Larger-diameter-portion of pump tube (15) Oil tank
(7) Reserve oil chamber (16) Tank gas chamber
(8) Pump rod (17) Oil
(9) Rear strut

RS-5

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SELF-LEVELING REAR SUSPENSION

Rear Suspension

2. WHEN THE VEHICLE HEIGHT IS LOWER THAN THE NORMAL LEVEL

D If the vehicle height is lowered below the normal level by loading, the flat section of the pump
rod goes into the smaller diameter portion of the pump tube to close the oil passage between the
flat section of the pump rod and the larger-diameter-portion of pump tube.
D When the piston rod is extended from the cylinder, the volume of the chamber in the pump is
increased, which causes the check valve of the pump rod to open. Therefore, the oil in the oil tank
is sucked into the chamber in the pump through the oil passage provided inside the pump rod.
(At that time, no oil is sucked from the chamber in the cylinder.)
D When the piston rod is retracted into the cylinder, the oil sucked into the chamber in the pump
opens the check valve of the pump tube and flows through the space between the pump tube and
piston rod into the chamber in the cylinder.
D As described above, repetition of extension and retraction of the piston rod causes the oil in the
oil tank to be pumped up little by little into the chamber in the cylinder, which increases the pres-
sure inside the chamber in the cylinder. The increased pressure inside the chamber in the cylinder
pushes up the piston rod until the vehicle resumes the normal height.
D When the normal height is resumed and the flat section of the pump rod enters the larger-diame-
ter-portion of the pump tube, pumping action does not take place any more.

RS-6

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見開き右

SELF-LEVELING REAR SUSPENSION

Rear Suspension

S4H0198A

(1) Chamber in pump

(2) Check valve of pump rod
(3) Larger-diameter-portion of pump tube
(4) Pump rod
(5) Piston rod
(6) Check valve of pump tube
(7) Pump tube
(8) Flat section of pump rod
(9) Chamber in cylinder
(10) Oil tank
(11) Oil

RS-7

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SELF-LEVELING REAR SUSPENSION

Rear Suspension

3. WHEN THE VEHICLE HEIGHT IS HIGHER THAN THE NORMAL LEVEL

D If the vehicle height is raised above the normal level by unloading, the relief orifice of the pump
rod can be located in the larger-diameter-portion of the pump tube during driving because of ex-
tension of the piston rod.
D At that time, as the pressure in the cylinder is higher than the pressure in the tank, the oil in the
cylinder returns to the tank through the relief orifice. This causes the vehicle finally to resume the
normal height.

S4H0199A

(1) Relief orifice (5) Pump tube

(2) Larger-diameter-portion of pump tube (6) Chamber in cylinder
(3) Pump rod (7) Oil tank
(4) Piston rod (8) Oil

RS-8

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DIFFERENTIALS DI
Page
1. Rear Differential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Limited Slip Differential (LSD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

DI

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REAR DIFFERENTIAL
Differentials

1. Rear Differential
A: VA-TYPE
The drive gear is a hypoid gear with nominal diameter of 152 mm (5.98 in). The drive pinion shaft
is supported by three bearings. The bearing preload is adjusted by selecting a spacer and washer
combination of a proper thickness. The drive pinion height is adjusted by properly selecting the
thickness of the washers located at the drive pinion neck using Dummy Shaft and Gauge.

H3H1196

DI-2

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REAR DIFFERENTIAL
Differentials

B: T-TYPE
The drive gear is a hypoid gear with a nominal diameter of 160 mm (6.30 in). The drive pinion shaft
is supported by three bearings. The bearing preload is adjusted by selecting a spacer and washer
combination of a proper thickness. The drive pinion height is adjusted by properly selecting the
thickness of the washers located at the drive pinion neck using Dummy Shaft and Gauge.
The T-type rear differential for the Europe models has an oil temperature sensor installed on the
rear section of the case. This sensor monitors the oil temperature and sends a signal to the com-
bination meter if the oil temperature exceeds the pre-determined level. The signal causes the indi-
cator lamp in the combination meter to illuminate, warning the driver of an abnormal oil tempera-
ture rise.
1. WITHOUT OIL TEMPERATURE SENSOR

H3H1060

DI-3

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REAR DIFFERENTIAL
Differentials

2. WITH OIL TEMPERATURE SENSOR

S3H0213B

(1) Oil temperature sensor

DI-4

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LIMITED SLIP DIFFERENTIAL (LSD)

Differentials

2. Limited Slip Differential (LSD)

A: OUTLINE
The limited slip differential is of a viscous coupling (V/C) type which automatically limits the differ-
ential action and distributes torque to the left and right wheels adequately to enhance driving sta-
bility when the left and right wheels are rotating at speeds different from each other during driving
on a slippery road (muddy, snow-covered or slushy road) or cornering.

B: STRUCTURE
The V/C type LSD has outer plates and inner plates arranged alternately. Each outer plate is
splined to the inside of the differential case at its outer periphery and each inner plate is splined
to the outer circumference of the left side gear at its inner periphery.
The inner plates are held in position by spacer rings while the outer rings can slide in the axial
direction along the spline teeth.
The space between the differential case and the left side gear is filled with a mixture of high viscos-
ity silicone oil and air and hermetically sealed with X-rings.

S3H0174B

(1) Spacer ring (6) Pinion gear

(2) Inner plate (7) Side gear (right)
(3) Outer plate (8) Differential case
(4) X-ring (9) Side gear (left)
(5) Pinion shaft (10) X-ring

DI-5

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LIMITED SLIP DIFFERENTIAL (LSD)

Differentials

C: OPERATION
1. WHEN RIGHT AND LEFT WHEELS ROTATE AT THE SAME SPEED
During normal straight-ahead driving where the right and left wheels rotate at the same speed,
the differential case and side gears rotate together, just as in conventional differentials. As a result,
driving torque is distributed equally to the right and left side gears.

S3H0175

DI-6

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LIMITED SLIP DIFFERENTIAL (LSD)

Differentials

2. WHEN RIGHT AND LEFT WHEELS ROTATE AT DIFFERENT SPEEDS

When a speed difference occurs between the right and left wheels, the differential case and the
left side gear do not rotate at the same speed any more. The speed difference between them cor-
responds to that between both the wheels. Because of the shear force caused in the silicone oil,
a differential torque is then generated, which limits differential action.
For example, if the left wheel spins due to small road resistance, a speed difference occurs be-
tween the right and left wheels. Since there is the V/C between the differential case and left side
gear, a differential torque corresponding to the speed difference is generated in the V/C. This dif-
ferential torque is transferred from the left wheel to the right wheel. As a result, a greater driving
torque is distributed to the right wheel which is rotating at a lower speed.
When the right wheel spins, the differential torque is transferred from the right wheel to the left
wheel. Also in this case, a torque greater by the differential torque than the torque to the spinning
wheel is transmitted to the wheel rotating at the lower speed.

When left wheel spins

S3H0176

DI-7

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LIMITED SLIP DIFFERENTIAL (LSD)

Differentials

When right wheel spins

S3H0177

D: SERVICE PROCEDURES FOR LSD

It is not recommended to disassemble the LSD assembly as component parts of LSD assembly
are not available individually.

DI-8

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DRIVE SHAFT SYSTEM DS

Page
1. Propeller Shaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

DS

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PROPELLER SHAFT
Drive Shaft System

1. Propeller Shaft
A: UJ TYPE (NON-TURBO MODEL)
The propeller shaft uses a 2-piece shaft and three universal joints (UJ).

S3H0007B

(1) Center bearing (A) Transmission side (B) Rear differential side

B: DOJ TYPE (TURBO MODEL)

The propeller shaft uses constant velocity joints for quiet operation of the driveline components.
The center joint is a double offset joint (DOJ) type which can extend and retract in the axial direc-
tions.

S3H0008B
(1) Center bearing (A) Transmission side
(2) DOJ (B) Rear differential side

DS-2

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FRONT AXLE
Drive Shaft System

2. Front Axle
A: GENERAL
D The inboard end of each axle shaft is connected to the transmission via a constant velocity joint
(shudder-less freering tripod joint: SFJ) which is flexible in the axial directions while the outboard
end is connected via a bell joint (BJ) to the wheel hub which is supported by a taper roller bearing
located inside the axle housing. The BJ features a large operating angle.
Both the constant velocity joints (SFJ and BJ) ensure smooth, regular rotation of the drive wheels
with minimum vibration.
D The bearing is a preloaded, non-adjustable tapered roller unit bearing.
Each hub is fitted in the axle housing via the tapered roller bearing.
D The BJ’s spindle is splined to the hub and is secured with an axle nut clinched to it.
D The disc rotor is an external mounting type. It is secured to the disc wheel using hub bolts to
facilitate maintenance of the disc rotor.

B4H2192A

(1) BJ (5) Axle nut (9) Baffle plate

(2) Axle housing (6) Hub (10) Hub bolt
(3) Tone wheel (7) Oil seal
(4) Bearing (8) Brake backing plate

DS-3

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FRONT AXLE
Drive Shaft System

B: FRONT DRIVE SHAFT

D A shudder-less freering tripod joint (SFJ) is used on the differential side of each front drive shaft.
The SFJ can be disassembled for maintenance. It provides a maximum operating angle of 25° and
can be moved in the axial directions.
D A bell joint (BJ) is used on the wheel side of each front drive shaft.
The BJ’s maximum operating angle is 47.5°.
D The BJ boots are made of a resin with improved durability.

B4H2193B

(1) SFJ (3) Transmission side

(2) BJ (4) Wheel side

DS-4

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REAR AXLE
Drive Shaft System

3. Rear Axle
A: NON-TURBO MODELS
D The inboard end of each axle shaft is connected to the transmission via a double offset joint:
DOJ which can extend and retract in the axial directions.
D The outboard end is supported by angular contact ball bearings located inside the axle housing
via a bell joint (BJ) which features a large operating angle. Both the constant velocity joints (DOJ
and BJ) ensure smooth, regular rotation of the drive wheels with minimum vibration.
D The bearing is a preloaded, non-adjustable angular contact ball unit type.
Each hub is fitted in the axle housing via the angular contact ball bearing.
D The BJ’s spindle is splined to the hub and secured with an axle nut clinched to it.
D The disc rotor or brake drum is held in position by the hub bolts and wheel nuts together with
the wheel. This facilitates removal and installation of the disc rotor or brake drum and thus im-
proves serviceability.

S3H0644A

(1) Bearing (5) BJ

(2) Hub (6) Hub bolt
(3) Axle nut (7) Baffle plate
(4) Oil seal

DS-5

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REAR AXLE
Drive Shaft System

B: TURBO MODELS
D The inboard end of each axle shaft is connected to the transmission via a double offset joint
(DOJ) which can extend and retract in the axial directions.
D The outboard end is supported by taper roller bearings located inside the axle housing via a
high efficiency compact ball fixes joint (EBJ) which features a large operating angle. Both the
constant velocity joint (DOJ and EBJ) ensure smooth, regular rotation of the drive wheels with mini-
mum vibration.
D The bearing is a preloaded, non-adjustable taper roller unit type.
Each hub is fitted in the axle housing via the taper roller bearing.
D The EBJ’s spindle is splined to the hub and secured with an axle nut clinched to it.
D The disc rotor is held in position by the hub bolts and wheel nuts together with the wheel. This
facilitates removal and installation of the disc rotor and thus improves serviceability.

S3H0645A

(1) Tapered roller bearing (5) EBJ

(2) Hub (6) Hub bolt
(3) Axle nut (7) Baffle plate
(4) Oil seal

DS-6

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REAR AXLE
Drive Shaft System

C: REAR DRIVE SHAFT

1. NON-TURBO MODELS
D A double offset joint (DOJ) is used on the differential side of each rear drive shaft. The DOJ can
be disassembled for maintenance. It provides a maximum operating angle of 23° and can be
moved in the axial directions.
D A bell joint (BJ) is used on the wheel side of each rear drive shaft. Its maximum operating angle
is 42°.

NF0156

(1) DOJ
(2) BJ
(3) Differential side
(4) Wheel side

2. TURBO MODELS
D A double offset joint (DOJ) is used on the differential side of each rear drive shaft. The DOJ can
be disassembled for maintenance. It provides a maximum operating angle of 23° and can be
moved in the axial directions.
D A high efficiency compact ball fixed joint (EBJ) is used on the wheel side of each rear drive shaft.
Its maximum operating angle is 42°.

NF0157

(1) DOJ
(2) EBJ
(3) Differential side
(4) Wheel side

DS-7

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REAR AXLE
Drive Shaft System

MEMO

DS-8

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ABS00

ABS ABS
Page
1. Anti-lock Brake System (ABS) .....................................................2

ABS

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

1. Anti-lock Brake System (ABS)

A: FEATURE
D The 5.3i type ABS has a hydraulic control unit, an ABS control module, a valve relay and a motor
relay integrated into a single unit (called “ABSCM & H/U”) for circuit simplicity and reduced weight.
D The ABS electrically controls the brake fluid pressure to each wheel to prevent the wheel from
locking during braking on slippery road surfaces, thereby enabling the driver to maintain the
directional control.
D If the ABS becomes inoperative, a fail-safe system is activated to ensure same level of braking
performance as with a conventional brake system. In that case, the warning light comes on to indi-
cate that the ABS is malfunctioning.
D The ABS is a 4-sensor, 4-channel system; the front wheel system is an independent control de-
sign*1, while the rear wheel system is a select-low control design*2.
*1: A system which controls the front wheel brakes individually.
*2: A system which applies the same fluid pressure to both the rear wheels if either wheel starts
to lock. The pressure is determined based on the lower of the frictional coefficients of both wheels.

S4H0346A

(1) ABS control module and hydraulic (5) G sensor (9) Wheel cylinder
control unit (ABSCM & H/U)
(2) Proportioning valve (6) ABS warning light (10) Automatic transmission control
module
(3) Diagnosis connector (7) Tone wheel (11) Brake switch
(4) Data link connector (8) ABS sensor (12) Master cylinder
(for SUBARU select monitor)

ABS-2

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ABS01

ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

B: FUNCTIONS OF SENSORS AND ACTUATORS

Name Function
ABS control module and ABSCM section D It determines the conditions of the wheels and the vehicle body from the
hydraulic control unit wheel speed data and controls the hydraulic unit depending on the re-
(ABSCM & H/U) sult.
D When the ABS is active, the ABSCM provides the automatic transmis-
sion control module with control signals which are used by the module
for cooperative control of the vehicle with the ABSCM.
D Whenever the ignition switch is placed at ON, the module performs a
self diagnosis sequence. If anything wrong is detected, the module cuts
off the system.
D It communicates with the SUBARU select monitor.
H/U section D When the ABS is active, the H/U changes fluid passages to the wheel cylin-
ders in response to commands from the ABSCM.
D It constitutes the brake fluid passage from the master cylinder to the wheel
cylinders together with the piping.
Valve relay section It serves as a power switch for the solenoid valves and motor relay coil. It
operates in response to a command from the ABSCM.
Motor relay section It serves as a power switch for the pump motor. It operates in response to
a command from the ABSCM.
ABS sensors (wheel speed sensors) They detect the wheel speed in terms of a change in the density of the
magnetic flux passing through them and convert it into an electrical signal.
The electrical signal is sent to the ABSCM.
Tone wheels They give a change in the magnetic flux density by the teeth around them-
selves to let the ABS sensors generate electrical signals.
G sensor It detects a change in acceleration in the longitudinal direction of the ve-
hicle and outputs it to the ABSCM as a voltage signal.
Stop light switch It provides information on whether the brake pedal is depressed or not to
the ABSCM. The ABSCM uses it to determine ABS operation.
ABS warning light It alerts the driver to an ABS fault. When the diagnosis connector and diag-
nosis terminal are connected, the light flashes to indicate a trouble code
stored in the ABSCM.
Automatic transmission control module It provides gear controls (fixing the speed at 3rd or changing power trans-
mission to front and rear wheels) in response to control signals from the
ABSCM.

ABS-3

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

S4H0019A

(1) ABS control module and hydraulic (9) Front right outlet solenoid valve (17) ABS warning light
control unit
(2) ABS control module section (10) Rear left inlet solenoid valve (18) Stop light switch
(3) Valve relay (11) Rear left outlet solenoid valve (19) Stop light
(4) Motor relay (12) Rear right inlet solenoid valve (20) G sensor
(5) Motor (13) Rear right outlet solenoid valve (21) Front left ABS sensor
(6) Front left inlet solenoid valve (14) Automatic transmission control (22) Front right ABS sensor
module
(7) Front left outlet solenoid valve (15) Diagnosis connector (23) Rear left ABS sensor
(8) Front right inlet solenoid valve (16) Data link connector (24) Rear right ABS sensor

ABS-4

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

C: PRINCIPLE OF ABS CONTROL

When the brake pedal is depressed during driving, the wheel speed decreases and the vehicle
speed does as well. The decrease in the vehicle speed, however, is not always proportional to the
decrease in the wheel speed. The non-correspondence between the wheel speed and vehicle
speed is called “slip” and the magnitude of the slip is expressed by the “slip ratio” which is defined
as follows:
Slip ratio = Vehicle speed – Wheel speed/Vehicle speed x 100%
When the slip ratio is 0%, the vehicle speed corresponds exactly to the wheel speed; when it is
100%, the wheels are completely locking (rotating at a zero speed) while the vehicle is moving.
The braking effectiveness is represented by the “coefficient of friction” between the tire and road
surface. The larger the coefficient, the higher the braking effectiveness. The diagram below shows
the relationship between the coefficient of friction and the slip ratio for two different road surface
conditions (asphalt-paved road and icy road), assuming that the same tires are used for both the
conditions and the vehicles are moving forward. Although the braking effectiveness (coefficient
of friction) depends on the road surface condition as shown and also on the type of the tire, its peak
range generally corresponds to the 8 – 30% range of the slip ratio.
The ABS controls the fluid pressure to each wheel so that a coefficient of friction corresponding
to this slip ratio range is maintained.
Control range by ABS
Coefficient of friction between tire

Asphalt-paved road
and road surface

Icy road

G4H0064A

ABS-5

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

D: ABS SENSORS
Each of the ABS sensors detects the speed of the corresponding wheel. The sensor consists of
a permanent magnet, coil and tone wheel. The magnetic flux produced by the permanent magnet
changes as each tooth of the tone wheel (which rotates together with the wheel) passes in front
of the magnet’s pole piece. The changing magnetic flux induces voltages at a frequency corre-
sponding to the wheel speed.

H4H1388B

(A) Front (1) Sensor body (4) Full speed

(B) Rear (2) Pole piece (5) Low speed
(3) Tone wheel (6) Permanent magnet

ABS-6

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

E: ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT (ABSCM & H/U)
D ABS CONTROL MODULE SECTION (ABSCM)
The ABSCM contains two microcontrol modules (MCMs): master and slave. Both the MCMs pro-
cess the same program and each MCM monitors the other’s outputs. If a mismatch occurs be-
tween their outputs, the ABSCM cuts off the system and activate the fail-safe function.
The ABSCM can store a maximum of 3 trouble codes in an EEP ROM. If more than 3 faults have
occurred, only the 3 most recent failures are stored and others are erased. Trouble codes remain
stored until they are internally or externally erased.
The ABSCM has a test routine (sequence control pattern) which facilitates checking of the hydrau-
lic control unit.
D ABS control
Using primarily the wheel speed data from each ABS sensor and secondarily the vehicle decelera-
tion rate data from the G sensor as parameters, the ABSCM generates a simulated vehicle speed
when there is a risk of wheel lock-up. Using the simulated vehicle speed (called “dummy” vehicle
speed) as a reference, the ABSCM determines the state of the wheel in terms of the tendency to-
ward lock-up. If the result shows that the wheels are about to lock, the ABSCM issues commands
to energize or de-energize the solenoid valves and activate the motor pump of the H/U to modulate
the brake fluid pressures that act on the wheel cylinders, thereby preventing the wheels from lock-
ing.
The ABSCM controls the right and left front wheel fluid pressures independently and the rear wheel
fluid pressures based on the wheel which is the most likely to lock (select-low control).
D Functions available using SUBARU select monitor
When the SUBARU select monitor is connected, the ABSCM allows it
D To read out analog data,
D To read out ON/OFF data,
D To read out or erase trouble code,
D To read out status information in the event of a fault (Freeze frame data), and
D To initiate ABS sequence control pattern.
D Indication functions
Under the control of the ABSCM, the ABS warning light provides the following three indication func-
tion:
D ABS fault alerting
D Trouble code indication (by flashing in the diagnosis mode)
D Valve ON/OFF indication (when sequence control pattern is initiated)

ABS-7

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

D HYDRAULIC CONTROL UNIT SECTION (H/U)

The H/U is a fluid pressure controller consisting of, among others, a motor, solenoid valves, a hous-
ing and relays. It also constitutes passage of the two diagonally split brake circuits.
D The pump motor drives an eccentric cam which in turn moves the plunger pump to generate
hydraulic pressure.
D The housing accommodates the pump motor, solenoid valve and reservoir. It also constitutes
a brake fluid passage.
D The plunger pump, when operated, draws the brake fluid from the reservoir, lets the fluid in a
wheel cylinder drain into the reservoir, and/or forces the fluid into the master cylinder.
D The outlet solenoid valve is a 2-position type. It opens or closes the brake fluid passage between
a wheel cylinder and the reservoir according to commands from the ABSCM.
D The inlet solenoid valve is duty-controlled to reduce brake fluid pulsation for minimum ABS op-
eration noise.
D The reservoir temporarily stores the brake fluid drained from a wheel cylinder when pressure
“decrease” control is performed.
D The damper chamber suppresses brake fluid pulsation which would occur during pressure “de-
crease” control in the fluid discharged from the plunger pump to minimize kickbacks of the brake
pedal.
D The valve relay controls power supply to the solenoid valves and motor relay in response to a
command from the ABSCM. In normal (IG ON) condition, the relay is closed to supply power to
the solenoid valves and motor relay. When an error occurs in the system, the valve relay is turned
OFF to keep the fluid pressure circuit in the normal mode (non-ABS mode).
D The motor relay closes and supplies power to the pump motor in response to a command from
the ABSCM during the ABS drive mode operations.
The H/U has four operating modes; normal mode (non-ABS mode), and three ABS active modes,
i.e., “increase”, “hold” and “decrease” modes.

ABS-8

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

MEMO

ABS-9

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

1. DURING NORMAL BRAKING (ABS NOT ACTIVE)

Both the inlet and outlet solenoid valves are not energized.
This means that the inlet port of the inlet solenoid valve is open, whereas the outlet port of the outlet
solenoid valve is closed. So the fluid pressure generated in the master cylinder is transmitted to
the wheel cylinder, producing a brake force.
NOTE:
For simplicity of explanation, operation of the hydraulic control unit is represented by operation
of a single wheel circuit.

ABS-10

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見開き右

ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

B4H0989A

(1) From master cylinder (8) Wheel cylinder

(2) Damper chamber (9) Outlet solenoid valve
(3) Inlet port open (10) Motor
(4) Inlet solenoid valve (11) Outlet port closed
(5) Check valve (12) De-energized
(6) De-energized (13) Reservoir
(7) Pump

ABS-11

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

2. PRESSURE “DECREASE” CONTROL (ABS ACTIVE)

Both the inlet and outlet solenoid valves are energized, which means that the inlet port is closed
and the outlet port is open.
In this state, the wheel cylinder is isolated from the master cylinder but open to the reservoir, so
the brake fluid in it can be drained into the reservoir, decreasing its pressure and reducing the
braking force of the wheel.
The brake fluid collected in the reservoir is forced into the master cylinder by the pump.
During this phase of ABS operation, the pump motor continues operating.
NOTE:
For simplicity of explanation, operation of the hydraulic control unit is represented by operation
of a single wheel circuit.

ABS-12

358
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見開き右

ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

B4H0990A

(1) From master cylinder (8) Wheel cylinder

(2) Damper chamber (9) Outlet solenoid valve
(3) Inlet port closed (10) Motor
(4) Inlet solenoid valve (11) Outlet port open
(5) Check valve (12) Energized
(6) Energized (13) Reservoir
(7) Pump

ABS-13

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

3. PRESSURE “HOLD” CONTROL (ABS ACTIVE)

The inlet solenoid valve is energized, so the inlet port is closed.
On the other hand, the outlet solenoid valve is de-energized, so the output port is also closed. In
this state, all the passages connecting the wheel cylinder, master cylinder and reservoir are
blocked. As a result, the fluid pressure in the wheel cylinder is held unchanged.
During this phase of ABS operation, the pump motor continues operating.
NOTE:
For simplicity of explanation, operation of the hydraulic control unit is represented by operation
of a single wheel circuit.

ABS-14

360
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見開き右

ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

B4H0991A

(1) From master cylinder (8) Wheel cylinder

(2) Damper chamber (9) Outlet solenoid valve
(3) Inlet port closed (10) Motor
(4) Inlet solenoid valve (11) Outlet port closed
(5) Check valve (12) De-energized
(6) Energized (13) Reservoir
(7) Pump

ABS-15

361
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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

4. PRESSURE “INCREASE” CONTROL (ABS ACTIVE)

Both the inlet and outlet solenoid valves are de-energized, which means that the inlet port of the
inlet solenoid valve is open, whereas the outlet port of the outlet solenoid valve is closed. So the
fluid pressure generated in the master cylinder is transmitted to the wheel cylinder and increased
fluid pressure in the wheel cylinder applies the brake with a larger force.
During this phase of ABS operation, the pump motor continues operating.
NOTE:
For simplicity of explanation, operation of the hydraulic control unit is represented by operation
of a single wheel circuit.

ABS-16

362
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. ABS01
見開き右

ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

B4H0992B

(1) From master cylinder (8) Wheel cylinder

(2) Damper chamber (9) Outlet solenoid valve
(3) Inlet port open (10) Motor
(4) Inlet solenoid valve (11) Outlet port closed
(5) Check valve (12) De-energized
(6) De-energized (13) Reservoir
(7) Pump

ABS-17

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

F: ABS CONTROL CYCLE CURVES

Depressing the brake pedal increases the brake fluid pressure in each wheel cylinder, which in
turn decreases the wheel speed (or increases the wheel deceleration rate). When the brake fluid
pressure is increased to a level of point “A” of the brake fluid pressure curve in the diagram below
(at which the wheel deceleration rate exceeds threshold “–b0”), the ABSCM makes a pressure
“hold” control. At the same time, the ABSCM calculates a “dummy” vehicle speed which is a refer-
ence speed it uses in the next stage of control.
When the wheel speed then drops below the slip ratio setting, i.e., a speed lower than the “dummy”
vehicle speed by the predetermined value (at point “B” of the pressure curve), the ABSCM makes
a control to prevent the wheel from locking, or a pressure “decrease” control.
As the wheel cylinder pressure decreases, the wheel speed starts increasing (or the wheel accel-
eration rate starts rising). When the wheel acceleration rate exceeds threshold “+b10” (at point “C”
of the pressure curve), the ABSCM makes a pressure “hold” control. When the wheel acceleration
rate exceeds threshold “+b20” (at point “D” of the pressure curve), the ABSCM recognizes that
wheel lock-up will not occur and then makes a pressure “increase” control.
When the wheel acceleration rate drops below threshold “+b20”, (at point “E” of the pressure
curve), the ABSCM starts pressure “hold” and “increase” control cycles at a given interval.
When the wheel deceleration rate then exceeds threshold “–b0” (at point “F” of the pressure curve),
the ABSCM immediately makes a pressure “decrease” control.
Slip ratio setting

B4H2239B

Brake fluid
Inlet valve Outlet valve
Pressure
Increase OFF OFF
Hold ON OFF
Decrease ON ON

ABS-18

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

G: ABS WARNING LIGHT

When a fault occurs in the signal transmission system or the ABSCM, the ABS warning light in the
combination meter comes on. At the same time, the current to the hydraulic control unit is inter-
rupted. The brake system then functions in the same manner as a system without ABS. The warn-
ing light utilizes a dual circuit design.
If the warning light comes on, one or more trouble codes should be stored in the control module.
They must be identified using the warning light’s code indicating function.

S4H0516A

(1) ABS warning light

ABS-19

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ANTI-LOCK BRAKE SYSTEM (ABS)

ABS

H: G SENSOR
The G sensor detects changes in the vehicle’s acceleration/deceleration rate in the longitudinal
direction.
The moving electrode of a capacitor in the sensor moves away from or close to the fixed electrode
as the vehicle accelerates or decelerates and the resulting change in the capacitance of the ca-
pacitor is outputs to the ABSCM as a change in the voltage.

B4H0988

ABS-20

366
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR00

BRAKES BR
Page
1. Front and Rear Disc Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Rear Drum Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Master Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Brake Booster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5. Proportioning Valve (Models without ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6. Proportioning Valve (Models with ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7. Hill Holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

BR

367
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FRONT AND REAR DISC BRAKES

Brakes

1. Front and Rear Disc Brakes

D The front disc brakes are of a ventilated disc type which features high heat dissipation and su-
perb braking stability. In addition, the front brakes quickly restores their original braking perfor-
mance even when they get wet.
The rear disc brakes are solid disc brakes.
D Each disc rotor, which is fitted on the outside of the hub, is secured together with the wheel using
the hub bolts. This facilitates its removal and installation.
D The inner pads of all the front brakes and the right rear brake are provided with wear indicators.

B4H2195C

(1) Disc rotor (3) Hub bolt

(2) Caliper body (4) Hub

BR-2

368
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FRONT AND REAR DISC BRAKES

Brakes

A: PAD WEAR INDICATOR

A wear indicator is provided on the inner disc brake pads. When the pad wears down to 1.5 mm
(0.059 in) the tip of the wear indicator comes into contact with the disc rotor, and makes a squeak-
ing sound as the wheel rotates. This alerts the driver to the situation.

H4H1056B

(1) Wear indicator (3) Worn pad

(2) New pad (4) Disc rotor

B: FRICTIONAL MATERIAL OF BRAKE PADS

The brake pads materials do not contain any asbestos which is harmful to human body.

BR-3

369
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REAR DRUM BRAKES

Brakes

2. Rear Drum Brakes

D The rear drum brakes are of a leading-trailing shoe type. When fluid pressure is applied to each
wheel cylinder, the piston expands the leading and trailing shoes. During expansion of the shoes,
the lower shoe return spring joint acts as a pivot. The shoes come in contact with the inner surface
of the drum, producing braking action.
D When brakes are applied during the forward movement, the tip of the brake leading shoe lining
is pressed against the inner surface of the drum so as to oppose the drum’s rotating force. This
increases the braking force. The trailing shoe, however, undergoes a force that pushes it back so
that braking force applied to the trailing shoe decreases.
The above shoe actions are reverse while the vehicle is moving backward; the braking force ex-
erted on the trailing shoe is greater than that on the leading shoe. This means that there is no differ-
ence in braking force between when the vehicle is moving forward and when it is reversing.
D An inspection hole is provided in the backing plate for easier inspection of the linings for wear.
The hole is closed with a rubber cap.

S4H0339A

(1) Wheel cylinder (4) Trailing shoe

(2) Upper shoe return spring (5) Lower shoe return spring
(3) Adjuster lever (6) Leading shoe

BR-4

370
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REAR DRUM BRAKES

Brakes

A: AUTOMATIC ADJUSTER
The brake lining-to-drum clearance is automatically adjusted by the automatic adjuster. When the
brake shoe is contracting after expansion, the adjuster lever rotates the adjuster assembly’s screw
to lengthen the adjuster assembly so that the clearance is maintained at the specified value.

S4H0340A

(1) Upper shoe return spring (5) Adjuster lever

(2) Adjuster assembly (6) Parking lever
(3) Leading shoe (7) Lower shoe return spring
(4) Trailing shoe

BR-5

371
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR03

MASTER CYLINDER
Brakes

3. Master Cylinder
D There is a brake fluid reservoir tank on the master cylinder. The reservoir is completely sealed
for extended service life of the brake fluid.
Models with ABS

B4H1934C

(1) Reservoir tank

(2) Secondary hydraulic chamber (chamber S)
(3) Primary hydraulic chamber (chamber P)

BR-6

372
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MASTER CYLINDER
Brakes

Models without ABS

S4H0013C

(1) Reservoir tank

(2) Secondary hydraulic chamber (chamber S)
(3) Primary hydraulic chamber (chamber P)

BR-7

373
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MASTER CYLINDER
Brakes

A: BRAKE FLUID LEVEL SWITCH

The brake fluid level switch is located inside the brake fluid reservoir tank and causes the brake
system warning light on the combination meter to come on when the fluid level has dropped below
the predetermined level.
The switch assembly consists of a reed switch (normally open) and a permanent magnet that is
incorporated in a float.
When the brake fluid level is normal, the float is far above the reed switch, so the force of the mag-
net is unable to act on the reed switch. The warning light circuit, therefore, remains open.
When the brake fluid level drops to a level approximately 30 mm (1.18 in) below the maximum level
and the float lowers accordingly, the magnet aligns with the reed switch, activating the reed switch
contact. The warning light then comes on to warn the driver of the situation.
The warning light may, although momentarily, illuminate even when the brake fluid level is normal
if the vehicle tilts or swing largely.

S4H0341A

(1) Warning light (2) Reed switch (3) Permanent magnet

BR-8

374
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR04

BRAKE BOOSTER
Brakes

4. Brake Booster
D The brake booster is a tandem type that uses two diaphragms. This design provides high brake
boosting effects in spite of a reduced diameter.
D The brake booster in every version has a fast-response functionality, which shortens the delay
between the start of pedal depression and the start of braking, thus providing a better pedal feel-
ing.

B4H1936A

(1) Push rod (5) Filter (9) Valve body

(2) Return spring (6) Silencer (10) Plunger valve
(3) Reaction disc (7) Operating rod (11) Diaphragm plate
(4) Key (8) Poppet valve (12) Valve return spring

BR-9

375
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR05

PROPORTIONING VALVE (MODELS WITHOUT ABS)

Brakes

5. Proportioning Valve (Models without ABS)

A proportioning valve for dual piping systems is adopted for controlling the braking force.

S4H0342A

(1) To rear wheel cylinder (RH) (7) Stopper

(2) To rear wheel cylinder (LH) (8) Piston
(3) From master cylinder (Secondary) (9) Balance piston
(4) From master cylinder (Primary) (10) Back-up ring
(5) Seal (11) Spring
(6) Fail-safe piston (12) Hold-spring

B4H0036

BR-10

376
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR05

PROPORTIONING VALVE (MODELS WITHOUT ABS)

Brakes

A: OPERATION DURING NORMAL CONDITION

When the fluid pressure in the master cylinder is low (the fluid pressure before the split point), the
piston is pressed by the spring load, so the valve remains inoperative. As a result, the fluid pres-
sure in the master cylinder is held equal to the fluid pressure in the rear wheel cylinder.
D When the master cylinder fluid pressure rises, the piston in the primary circuit is moved right-
ward against the spring load, and brought into contact with the seal (a) (as shown in the figure).
The master cylinder fluid pressure chamber (chamber A) is therefore cut off from the rear wheel
cylinder fluid pressure chamber (chamber B), and the fluid pressure to the rear wheel cylinder is
thus controlled. (The pressure at this moment is the split point pressure.)
If the fluid pressure in chamber A rises further, the piston is moved leftward getting clear of the seal
(a), and this causes the fluid pressure in chamber B to rise. The piston is then moved rightward,
and brought into contact with the seal (a) again. The piston then leaves and comes into contact
with the seal (a) in this way repeatedly, thereby controlling the fluid pressure in the rear wheel cylin-
der.
D When the fluid pressure in chamber B is controlled in the secondary circuit, the balance piston
is moved rightward by the difference in fluid pressure between chamber B and chamber C. As the
balance piston is brought into contact with the seal (b), the fluid pressure in chamber D is now
controlled. Since sectional areas A1 and A2 are equal, the balance piston is pushed by the same
forces from the right and left. If the fluid pressure rises in chamber B, the balance piston performs
control to equalize the fluid pressure in chamber D and chamber B by leaving and coming into
contact with the seal (b) repeatedly.

S4H0343A

(1) To rear wheel cylinder (8) Chamber A

(2) From master cylinder (Secondary) (9) Piston
(3) From master cylinder (Primary) (10) Chamber D
(4) Balance piston (11) Seal (b)
(5) A1 (12) Chamber C
(6) A2 (13) Chamber B
(7) Seal (a)

BR-11

377
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PROPORTIONING VALVE (MODELS WITHOUT ABS)

Brakes

B: OPERATION WHEN A CIRCUIT FAILURE OCCURS

1. FAILURE OF PRIMARY CIRCUIT
If the primary circuit fails, the fail-safe piston and balance piston are moved rightward by the mas-
ter-cylinder-induced pressure in the secondary circuit until the piston contacts the plug. In this
case, the balance piston remains clear of the seal (b), so no split point is created. That is, the fluid
pressure in the secondary side rear wheel cylinder is equal to the fluid pressure in the master cylin-
der.

S4H0345A

(1) To rear wheel cylinder (6) Piston

(2) To rear wheel cylinder (inoperative) (7) Seal (b)
(3) From master cylinder (Secondary) (8) Balance piston
(4) From master cylinder (Primary) (inoperative) (9) Plug
(5) Fail-safe piston

BR-12

378
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR05

PROPORTIONING VALVE (MODELS WITHOUT ABS)

Brakes

2. FAILURE OF SECONDARY CIRCUIT

If the secondary circuit fails, the balance piston is moved leftward by the fluid pressure in chamber
B until the end of the piston contacts the stopper. Since sectional area A1 is greater than A0, the piston
remains stationary even after the master cylinder fluid pressure has reached the split point, and the
piston is kept clear of the seal (a). Hence, no split point is created, and the rear wheel cylinder fluid
pressure of the primary circuit is kept equal to the master cylinder fluid pressure.

S4H0344A

(1) To rear wheel cylinder (inoperative) (7) Piston

(2) To rear wheel cylinder (8) Balance piston
(3) From master cylinder (Secondary) (inoperative) (9) A1
(4) From master cylinder (Primary) (10) Seal (a)
(5) Chamber B (11) A0
(6) Stopper

BR-13

379
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR06

PROPORTIONING VALVE (MODELS WITH ABS)

Brakes

6. Proportioning Valve (Models with ABS)

The proportioning valve prevents the rear wheels from locking and resultant skidding that would
occur during hard braking due to transfer of vehicle weight toward the front wheels. The valve dis-
tributes a reduced pressure to the rear wheel brakes as compared with the pressure to the front
wheel brakes when a specified master cylinder fluid pressure (called “split point”) is exceeded
as shown in the diagrams below.

S4H0130

A: OPERATION
1) Operation before the split point
The piston is held pressed toward the left by the spring so that the valve is kept away from its seat.
Under this condition, fluid pressure “P3” to the rear wheel cylinders is equal to fluid pressure “P2”
from the master cylinder.

H4H1398B

(1) To rear wheel cylinder (4) Spring

(2) From master cylinder (5) Piston
(3) Seat (6) Valve

BR-14

380
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR06

PROPORTIONING VALVE (MODELS WITH ABS)

Brakes

2) Operation at the split point pressure

When pressure “P2” increases to the split point pressure, force “f2” is generated. (Piston’s cross
sectional area “A” has been selected so that the force is generated starting with the split point pres-
sure.) The pressure pushes the piston rightward, overcoming spring force “F”. As a result, the
valve seat moves together with the piston rightward and comes in contact with the valve, blocking
the passage toward the rear wheel cylinders.

H4H1399B

(1) To rear wheel cylinder (4) Spring

(2) From master cylinder (5) Piston
(3) Seat (6) Valve

3) Operation after reaching the split point pressure

Immediately before the fluid passage toward the rear wheel cylinders is closed, pressure “P2” is
slightly higher than pressure “P3”. So the piston can move in the spring force acting direction and
the fluid can flow to the wheel cylinders. However, as soon as pressure “P2” becomes equal to “P3”,
the valve closes.
This cycle is repeated as long as the pedal is depressed further, but pressure increasing rate of
the rear wheel cylinders is smaller than that of the front wheel cylinders.

BR-15

381
見開き左W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07

HILL HOLDER
Brakes

7. Hill Holder
The hill holder is a device that facilitates starting on an uphill road. With the help of this device, even
an unexperienced driver can start the vehicle smoothly.
When starting the vehicle on an uphill road, the driver depresses the clutch pedal while keeping
the brake pedal depressed and then releases the brake pedal. At this time the hill holder keeps
the brakes still applied until the clutch pedal is released. This enables the driver to start the vehicle
in a usual manner by depressing the accelerator while releasing the clutch pedal without being
troubled by brake pedal operation.

BR-16

382
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07
見開き右

HILL HOLDER
Brakes

S4H0577A

(A) Models without ABS

(B) Models with ABS
(1) Master cylinder (5) Clutch pedal (9) Front brake
(2) Proportioning valve (6) Clutch cable (10) Rear brake
(3) Brake booster (7) Pressure hold valve (11) ABS control module/
hydraulic control unit
(4) Brake pedal (8) Pressure hold valve (PHV) cable

BR-17

383
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07

HILL HOLDER
Brakes

A: PRESSURE HOLD VALVE (PHV)

D The PHV is located on the piping that connects the master cylinder and the ABS control module/
hydraulic control unit. It has a camshaft which turns either way by rotation of the lever which is
linked to the clutch pedal. The cam of the crankshaft allows the pushrod in the PHV to move right-
ward (in the drawing below) under the force of a spring when the clutch pedal is depressed and
pushes it leftward against the force of the spring when the clutch pedal is released. At the left of
the pushrod, there is a ball housed in a chamber which has a seat for the ball. When the vehicle
is on a level road, this ball stays at the left (front) of the chamber, but on an uphill road, it tends to
move rightward by the gravity. In the latter case, the ball makes contact with the seat unless it is
forced to leave the seat by a leftward movement of the pushrod (resulting from release of the clutch
pedal).
D When the vehicle is stopped on an uphill road, the driver depresses both the brake and clutch
pedals. In this condition, the ball is in the rear (right) position, making contact with its seat and pre-
venting flow of the brake fluid toward the master cylinder. The driver then release the brake pedal
while keeping the clutch pedal depressed to restart the vehicle. The brakes, however, remains ap-
plied because the pressure in the line to the wheel cylinders is kept unreleased. Then, the driver
can release the clutch pedal in the same way as with on a level road while depressing the accelera-
tor pedal since the release of the clutch pedal causes the pushrod to push the ball away from its
seat and the brakes are released.

S4H0204B

(1) Body (8) Pushrod (A) Front

(2) Camshaft (9) Spring (B) To rear RH brake
(3) Ball (10) Boot (C) To front LH brake
(4) Ball guide (11) Cover (D) From master cylinder
(5) Seat (12) Lever
(6) Plate spring (13) O-ring
(7) Cap (14) O-ring

BR-18

384
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07

HILL HOLDER
Brakes

1. CONDITIONS IN WHICH THE HILL HOLDER OPERATES

The hill holder operates only when the clutch and brake pedals are depressed with the vehicle
stopped on an uphill road.
In this condition, the PHV’s ball blocks the fluid passage back to the master cylinder and, therefore,
the hydraulic pressure in the wheel cylinder circuits is maintained even after the brake pedal has
been released as long as the clutch pedal is held depressed.

G4H0057

2. CONDITIONS IN WHICH THE HILL HOLDER DOES NOT OPERATE

The hill holder does not operate in the following conditions:
D During acceleration and constant speed driving on an uphill road
Since driver does not depress the clutch pedal during acceleration or driving at a constant speed,
the pushrod keeps the ball away from the seat. The hill holder cannot maintain the pressure in the
wheel cylinder circuits when the brake pedal is released.

G4H0058

BR-19

385
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07

HILL HOLDER
Brakes

D During deceleration on an uphill road

Even if the clutch pedal is depressed during deceleration, the ball is kept away from the seat by
the inertia force. So, the hill holder cannot maintain the wheel cylinder circuit pressure.

G4H0059

D When stopping on an uphill road without depressing the clutch pedal

If the driver does not depress the clutch pedal simultaneously with the brake pedal when stopping
the vehicle on an uphill road, the hill holder cannot keep the wheel cylinder circuit pressure unre-
leased when the brake pedal is release.

G4H0060

D On a level road
The ball does not move itself toward its seat except when the vehicle is braked during reversing,
so the hill holder does not function during level road driving.

G4H0061

BR-20

386
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07

HILL HOLDER
Brakes

B: OPERATIONAL PRECAUTIONS
D The hill holder is a device that facilitates starting on an uphill road. When stopping on an uphill
road, therefore, the driver must keep the brake pedal depressed or set the parking brake firmly.
D The hill holder may not function on a slope with a small angle of inclination.
D If the brake force is insufficient to hold the vehicle after releasing the brake pedal with the clutch
pedal depressed, depress the brake pedal again with a stronger force.
D If the clutch pedal is released halfway and then depressed again (for example, when the driver
abandons an attempt of start or changes gear to the low gear from another improperly selected
gear), the pressure in the wheel is not retained any more. The driver, therefore, must depress the
brake pedal again to use the hill holder function next time.
D Before leaving the vehicle, the driver must apply firmly the parking brake and confirm that the
vehicle does not move after releasing the clutch pedal.
D When reversing on a level road, the phenomena listed below may occur. These phenomena are
caused by activation of the hill holder and do not mean an abnormality.
D Braking effect continues when the vehicle is reversed with the clutch and brake pedals de-
pressed and then the brake pedal released.
D A slight shock occurs in the vehicle when moving the vehicle forward after a reverse move-
ment.

BR-21

387
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BR07

HILL HOLDER
Brakes

MEMO

BR-22

388
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PB00

PARKING BRAKE PB
Page
1. Parking Brake (Rear Disc Brakes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Parking Brake (Rear Drum Brakes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

PB

389
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PB01

PARKING BRAKE (REAR DISC BRAKES)

Parking Brake

1. Parking Brake (Rear Disc Brakes)

The parking brake uses a drum housed in the disc rotor of each rear disc brake. The shoes are
mechanically controlled through linkage and cables.

B4H1939

PB-2

390
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PB01

PARKING BRAKE (REAR DISC BRAKES)

Parking Brake

A: OPERATION
1. SETTING
When the parking brake lever is pulled, the shoe actuating lever to which the end of the parking
brake cable is connected turns the strut in direction “F” around point “P”.
The strut then presses the brake shoes A and B against the drum. These brake shoes utilize a float-
ing design and are movably supported by hold-down pins. The force applied to brake shoe A and
the reaction force “F” applied to the brake shoe B via point “P” press them against the brake drum.

NF0107

(1) Parking brake cable (5) Brake shoe B

(2) Lever (6) Shoe return spring
(3) Strut (7) Shoe hold down pin
(4) Brake shoe A (8) Point “P”

PB-3

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PB01

PARKING BRAKE (REAR DISC BRAKES)

Parking Brake

2. RELEASING
When the parking brake lever is returned to the release position and the parking brake cables are
slackened, the brake shoes A and B are moved back to their original positions by the tension of
return springs, so that the parking brake is released.

NF0108

(1) Parking brake cable (5) Brake shoe B

(2) Lever (6) Shoe return spring
(3) Strut (7) Shoe hold down pin
(4) Brake shoe A (8) Point “P”

PB-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PB02

PARKING BRAKE (REAR DRUM BRAKES)

Parking Brake

2. Parking Brake (Rear Drum Brakes)

When the parking brake lever is moved up, the parking lever in each rear drum brake moves
around point “A” so that the trailing shoe expands. The leading shoe also expands by way of the
adjuster assembly. The shoes are thus pressed against the drum to generate a wheel locking
force.
(1)
(2)

(3)

(4)

(5)

(6)
(7)

(3)
(A) (B)
(2) (8)
(6)

(5)
(5)

(8)
(4)

(6) (9) (9)

(7)

B4H1632B

(1) Wheel cylinder (7) Lower shoe return spring

(2) Upper shoe return spring (8) Adjuster assembly
(3) Point “A” (9) Parking lever
(4) Adjuster lever
(5) Trailing shoe (A) Automatic brake lining clearance adjustment mechanism
(6) Leading shoe (B) Parking brake mechanism

PB-5

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PB02

PARKING BRAKE (REAR DRUM BRAKES)

Parking Brake

MEMO

PB-6

394
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POWER ASSISTED SYSTEM

(POWER STEERING) PS
Page
1. Tilt Steering Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Power Steering System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

PS

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS01

TILT STEERING COLUMN

Power Assisted System (Power Steering)

1. Tilt Steering Column

A: TILT MECHANISM
D The steering wheel vertical position can be adjusted within a 32 mm (1.26 in) range by using
the tilt lever to unlock the steering column and lock it again at the desired position.

S4H0020B

(1) Tilt steering column

(2) Tilt lever

PS-2

396
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS01

TILT STEERING COLUMN

Power Assisted System (Power Steering)

B: ENERGY-ABSORBING MECHANISM
D To absorb the backward movement energy generated in the engine in the event of a frontal colli-
sion, an elliptical fitting type steering column pipe has been adopted. When an impact load ex-
ceeding a certain level is applied to the steering column, the elliptical fittings crash and their ends
come in contact with each other. The column bending load is supported by the fittings.
D Another measure to alleviate impact on the driver in the event of a collision is the expansion plate
which is located between the steering column and the tilt bracket attached to the steering support
beam. When a large impact load is applied to the steering column, the expansion plate is de-
formed and expand progressively. The impact energy is absorbed during this process.

S4H0021B

(A) Before absorption of impact energy (1) Elliptical fitting

(B) After absorption of impact energy (2) Column
(3) Expansion plate
(4) Tilt bracket

PS-3

397
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS01

TILT STEERING COLUMN

Power Assisted System (Power Steering)

C: STEERING SUPPORT BEAM

The steering column is held in position by a support beam which is installed crosswise in the ve-
hicle body at a level close to the steering wheel to reduce the overhang distance of the steering
wheel from the supporting point of the column. The steering shaft upper bearing is also located
close to the steering wheel to increase supporting efficiency as well as to minimize vibration of the
steering wheel.

S4H0022B

(1) Steering support beam

PS-4

398
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS01

TILT STEERING COLUMN

Power Assisted System (Power Steering)

MEMO

PS-5

399
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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

2. Power Steering System

A: HYDRAULIC SYSTEM
D The fluid pump is directly driven by the engine through a belt.
D The fluid pressure is maintained almost constant regardless of change in the engine speed by
the function of the flow control valve. The pressure-regulated fluid is delivered to the control valve
via hose A.
D When the steering wheel is turned, the rotary control valve connected to the pinion shaft opens
the hydraulic circuit corresponding to the direction in which the steering wheel is turned. The fluid
then flows into chamber A or B via pipe A or B.
D The fluid pressure in chamber A or B acts on the rack piston in the same direction as that in which
the rack shaft is moved by rotation of the steering wheel. This helps reduce the effort required of
the driver to operate the steering wheel.
D Movement of the rack piston causes the fluid in the other chamber to return to the reservoir tank
via pipe A or B, control valve, and hose B.
D As the steering shaft is connected to the pinion shaft mechanically via the rotary control valve,
the steering system can operate as a manual system even if the hydraulic system becomes in-
operative.
D To control the maximum fluid pressure, a relief valve is built into the fluid pump to prevent build-
up of an excessive fluid pressure.

PS-6

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見開き右

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

S4H0023B

(1) Power cylinder (11) Steering wheel

(2) Rack piston (12) Tank
(3) Rack shaft (13) Vane pump
(4) Pinion shaft (14) Relief valve
(5) Chamber A (15) Hose A
(6) Chamber B (16) Hose B
(7) Pipe A (17) Pump control valve
(8) Pipe B (18) Fluid pump
(9) Control valve (19) Engine
(10) Steering shaft

PS-7

401
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

B: GEARBOX ASSEMBLY
1. POWER CYLINDER
The gearbox integrates the control valve and power cylinder into a single unit. The rack shaft
serves as a power cylinder piston. The rotary control valve is located around the pinion shaft.
The rotary control valve and power cylinder are connected to each other by two pipes through
which hydraulic fluid flows.
LHD MODEL

S4H0024A

(1) Piston (4) Power cylinder

(2) Rack shaft (5) Pinion shaft
(3) Cylinder (6) Control valve

RHD MODEL

S4H0200C

(1) Piston (4) Power cylinder

(2) Rack shaft (5) Pinion shaft
(3) Cylinder (6) Control valve

PS-8

402
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

MEMO

PS-9

403
見開き左W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

2. ROTARY CONTROL VALVE

The rotary control valve consists of a rotor (which rotates together with the steering shaft), a pinion
(which is connected to the rotor and torsion bar), and a sleeve (which rotates together with the
pinion). The rotor and sleeve have grooves C and D, respectively, which form fluid passages V1
through V4.
The pinion is in mesh with the rotor with adequate clearance, which enable the rack to be moved
manually by rotating the steering shaft (fail-safe feature).
LHD MODEL

S4H0025C

PS-10

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02
見開き右

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

(1) Torsion bar (12) Torsion bar

(2) Sleeve (13) Rotor
(3) Rotor (14) Sleeve
(4) Pinion (15) Fluid return line (to reservoir tank)
(5) Pinion-to-rotor engagement (fail-safe feature) (16) Pinion
(6) Fluid passage V1 (17) Torsion bar
(7) Fluid passage V2 (18) Rotor
(8) Fluid passage V3
(9) Fluid passage V4 (A) Cross-sectional view A (fluid passage switching cir-
cuit)
(10) Groove C (B) Cross-sectional view B (pinion-to-rotor engagement)
(11) Groove D

PS-11

405
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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

RHD MODEL

S4H0333B

(1) Torsion bar (12) Torsion bar

(2) Sleeve (13) Rotor
(3) Rotor (14) Sleeve
(4) Pinion (15) Oil return line (to reservoir)
(5) Fail-safe function (16) Valve housing
(6) Fluid passage V1 (17) Rotor
(7) Fluid passage V2 (18) Pinion
(8) Fluid passage V3
(9) Fluid passage V4 (A) Cross-sectional view A of oil passage switching cir-
cuit
(10) Groove C (B) Cross-sectional view B of fail-safe function
(11) Groove D

PS-12

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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

D Principle of operation
When the torsion bar is twisted by a rotational force applied to the steering wheel, the relative posi-
tion between the rotor and sleeve changes. This changes the cross-sectional area of fluid pas-
sages V1, V2, V3 and V4. The fluid passages are thus switched and the fluid pressure is controlled
in accordance with the operation of the steering wheel.
D When no steering force is applied:
The rotor and sleeve are held at the neutral position. Fluid passages V1, V2, V3 and V4, which
are formed by grooves C and D are open equally. Under this condition, the fluid from the pump
returns to the reservoir tank so that neither fluid pressure builds up nor the rack piston moves
in the power cylinder.

LHD MODEL

S4H0334A

(1) Chamber A (4) V2 (7) From fluid pump

(2) Chamber B (5) V3 (8) To A
(3) V1 (6) V4 (9) To B

PS-13

413
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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

RHD MODEL

S4H0335A

(1) Chamber A (4) V2 (7) From fluid pump

(2) Chamber B (5) V3 (8) To A
(3) V1 (6) V4 (9) To B

PS-14

408
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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

D When steering force is applied:

When the steering wheel is turned to the right, for example, fluid passages V1 and V3 are opened
while fluid passages V2 and V4 are nearly closed.
At this point, the fluid pressure in chamber A of the power cylinder increases depending on the
degree of closure of fluid passages V2 and V4 so that the rack piston moves to the right. The
fluid in chamber B, on the other hand, is drained through fluid passage V3 into the reservoir tank.

LHD MODEL

S4H0336A

(1) Chamber A (4) V2 (7) From fluid pump

(2) Chamber B (5) V3 (8) To A
(3) V1 (6) V4 (9) From B

PS-15

409
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

RHD MODEL

S4H0337A

(1) Chamber A (4) V2 (7) From fluid pump

(2) Chamber B (5) V3 (8) To A
(3) V1 (6) V4 (9) From B

D Fail-safe feature
If fluid pressure fails to build up due to, for example, a broken fluid pump drive belt, the steering
wheel rotating torque is transmitted from the valve rotor to the pinion through mechanical engage-
ment between them.

PS-16

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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

MEMO

PS-17

411
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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

C: FLUID PUMP
1. NON-TURBO MODEL
D The fluid pump is belt-driven by the engine. The fluid flow is controlled according to the engine
speed so that an adequate steering resistance is given during high-speed operation.
The fluid pump is a variable capacity type vane pump whose delivery rate per rotation decreases
as the engine speed increases. The pump is integral with a pump control valve and relief valve.

PS-18

412
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02
見開き右

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

S4H0026B

(1) Suction (6) Discharge

(2) Fluid pump (7) Rotor
(3) Pump control valve (8) Pin (Pivot for cam ring swing action)
(4) Vane (9) Variable orifice
(5) Cam ring (10) Relief valve

PS-19

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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

D The vane pump consists of a rotor, a cam ring, and eleven vanes.
When the rotor rotates, the vane in each slot of the rotor is radially moved out by centrifugal force
and pressed against the cam ring. The fluid from the suction port is confined in chambers formed
between two adjacent vanes and carried to the discharge port. Since the cam ring is movable in
relation to the rotor, the volume of each chamber is variable. This enables the delivery rate per rota-
tion of the pump to be changed.

S4H0249B

(1) Suction
(2) Vane
(3) Rotor
(4) Cam ring
(5) Discharge

PS-20

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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

D FLOW CONTROL
The variable capacity pump changes its delivery rate per rotation by changing the degree of ec-
centricity of the cam ring according to its rotating speed (engine speed).

Delivery rate per unit time

Fluid flow

Delivery rate per rotation of pump

Idling
Low- Mid- High
range range speeds
speeds speeds

S4H0028B

NOTE:
In the following description, pump speed ranges will be indicated using the speed points A
through D shown in the drawing above.

PS-21

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見開き左W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

Low-range-speed operation (A – B range)

In this speed range, as well as in all the other speed ranges, two different pump discharge pressur-
es are always applied to the control valve; one is directly led from the discharge port to the left end
of the valve and the other is led through an orifice (variable orifice) to the right end of the valve.
Since the orifice has a pressure reducing effect, the latter pressure is lower than the former.
When the pump is operating at a low speed, its discharge pressure is also low, resulting in only
small difference between the two pressures. In this condition, the valve stays pushed leftward by
the spring, allowing the non-pressurized tank fluid to enter chamber A. To chamber B, on the other
hand, the orifice-reduced discharge pressure is applied, so the cam ring is pushed leftward by
the cam ring spring. This makes the eccentricity of the cam ring a maximum and, therefore, the
delivery rate per rotation of the pump become a maximum.

PS-22

416
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02
見開き右

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

S4H0029B

(1) Control valve (6) Variable orifice

(2) Tank fluid (7) Pressure chamber A
(3) Control valve spring (8) Pressure chamber B
(4) Gear box (9) Cam ring
(5) Cam ring spring

PS-23

417
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

Mid-range-speed operation (B – C range)

During mid-range speed operation, the pump increases its delivery rate. Since the pressure be-
fore passing through the variable orifice increases, the control valve moves rightward, overcoming
the tension of the control valve spring. This movement of the control valve allows the pressure up-
stream of the variable orifice to be directed to chamber A. On the other hand, chamber B receives
a pressure reduced by the orifice. This means that the pressure in chamber A is higher than that
in chamber B. As a result, the cam ring moves rightward against the tension of the cam spring.
This causes the delivery rate per rotation of the pump to be reduced, so that the flow rate of the
fluid to the steering gear box decreases accordingly.

S4H0030B
(1) Control valve (6) Variable orifice
(2) Tank fluid (7) Pressure chamber A
(3) Control valve spring (8) Pressure chamber B
(4) Gear box (9) Cam ring
(5) Cam ring spring

PS-24

418
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

High-speed operation (C – D range)

When the pump speed increases to a certain point, the cam ring moves to the extreme right posi-
tion, making the variable orifice opening the minimum. In this state, the delivery rate per rotation
of the pump becomes the minimum and the minimum delivery rate is maintained even if the pump
speed increases further.

S4H0031B

(1) Control valve (6) Variable orifice

(2) Tank fluid (7) Pressure chamber A
(3) Control valve spring (8) Pressure chamber B
(4) Gear box (9) Cam ring
(5) Cam ring spring

PS-25

419
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

Maximum pressure control

When the overall delivery rate of the pump exceeds a preset value, the relief valve opens to allow
part of the discharged fluid to flow toward the suction side of the pump, thereby controlling the
maximum pressure.

S4H0032B

(1) Tank fluid

(2) Relief valve
(3) Gear box

PS-26

420
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

2. TURBO MODEL
D The reservoir tank is mounted on the vehicle body.
D The fluid pump is belt-driven by the engine. The fluid flow is controlled according to the engine
speed so that an adequate steering resistance is given during high-speed operation.
The fluid pump is a variable capacity type vane pump whose delivery rate per rotation decreases
as the engine speed increases. The pump is integral with a pump control valve and relief valve.

S4H0576A

(A) Section A–A

(B) Section B–B
(1) Suction (6) Rotor
(2) Fluid pump (7) Pin (Pivot for cam ring swing action)
(3) Pump control valve (8) Variable orifice
(4) Vane (9) Relief valve
(5) Cam ring

PS-27

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

D The vane pump consists of a rotor, a cam ring, and eleven vanes.
When the rotor rotates, the vane in each slot of the rotor is radially moved out by centrifugal force
and pressed against the cam ring. The fluid from the suction port is confined in chambers formed
between two adjacent vanes and carried to the discharge port. Since the cam ring is movable in
relation to the rotor, the volume of each chamber is variable. This enables the delivery rate per rota-
tion of the pump to be changed.

B4H2478A

(1) Suction
(2) Vane
(3) Rotor
(4) Cam ring
(5) Discharge

PS-28

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

D FLOW CONTROL
The variable capacity pump changes its delivery rate per rotation by changing the degree of ec-
centricity of the cam ring according to its rotating speed (engine speed).

Delivery rate per unit time

Fluid flow

Delivery rate per rotation of pump

Idling
Low- Mid- High
range range speeds
speeds speeds

S4H0028B

NOTE:
In the following description, pump speed ranges will be indicated using the speed points A
through D shown in the drawing above.

PS-29

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. PS02

POWER STEERING SYSTEM

Power Assisted System (Power Steering)

Low-range-speed operation (A – B range)

In this speed range, as well as in all the other speed ranges, two different pump discharge pressur-
es are always applied to the control valve; one is directly led from the discharge port to the left end
of the valve and the other is led through an orifice (variable orifice) to the right end of the valve.
Since the orifice has a pressure reducing effect, the latter pressure is lower than the former.
When the pump is operating at a low speed, its discharge pressure is also low, resulting in only
small difference between the two pressures. In this condition, the valve stays pushed leftward by
the spring, allowing the non-pressurized reservoir tank fluid to enter chamber A. To chamber B,
on the other hand, the orifice-reduced discharge pressure is applied, so the cam ring is pushed
leftward by the cam ring spring. This makes the eccentricity of the cam ring a maximum and, there-
fore, the delivery rate per rotation of the pump become a maximum.

B4H2479A

(1) Control valve (6) Variable orifice

(2) Reservoir tank fluid (7) Pressure chamber A
(3) Control valve spring (8) Pressure chamber B
(4) Gear box (9) Cam ring
(5) Cam ring spring

PS-30

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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

Mid- and high-range-speed operation (B – D range)

During mid- and high-range speed operation, the pump increases its delivery rate. Since the pres-
sure before passing through the variable orifice increases, the control valve moves rightward,
overcoming the tension of the control valve spring. This movement of the control valve allows the
pressure upstream of the variable orifice to be directed to chamber A after being adjusted to a
necessary pressure* by the port opening area created by the control valve. On the other hand,
chamber B receives the reservoir pressure (suction pressure). This means that the pressure in
chamber A is higher than that in chamber B. As a result, the cam ring moves rightward against
the tension of the cam spring. This causes the delivery rate per rotation of the pump to be reduced,
so that the flow rate of the fluid to the steering gear box decreases accordingly.
The above control is performed when the pump is operating at a speed in the B – D range.
* The “necessary pressure” for chamber A is a pressure required to move the cam ring to the posi-
tion corresponding to each predetermined flow rate (pump delivery rate). The pressure is ob-
tained by changing the port opening area appropriately through displacement of the control valve.
The displacement of the control valve is determined by how much the pressure before the variable
orifice is different from that after the orifice.

B4H2480A
(1) Control valve (6) Variable orifice
(2) Reservoir tank fluid (7) Pressure chamber A
(3) Control valve spring (8) Pressure chamber B
(4) Gear box (9) Cam ring
(5) Cam ring spring (10) Opening area

PS-31

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POWER STEERING SYSTEM

Power Assisted System (Power Steering)

Maximum pressure control

When the hydraulic circuit in the steering gear box is closed as a result of a steering action, the
pressure in the circuit increases to a very high level. The relief valve prevents the pressure from
exceeding a preset safe level in the following way:
If the fluid in the circuit is pressurized to the preset pressure, the fluid pushes the ball of the valve
overcoming the tension of the relief spring. Through the opened relief valve, the fluid makes its way
to the pump’s suction side passage, thus maintaining the circuit pressure at a level lower than the
preset pressure.

B4H2481A

(1) Reservoir tank fluid

(2) Relief valve
(3) Gear box
(4) Relief spring

PS-32

426
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC00

HVAC SYSTEM
(HEATER, VENTILATOR AND A/C) AC
Page
1. Heater System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Switch Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Mode Selector Switch and Air Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Blower System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Air Conditioning Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7. Condenser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8. Receiver Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9. Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10. Evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11. Expansion Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
12. Compressor Clutch “ON” Delay System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
13. Compressor Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

AC

427
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC01

HEATER SYSTEM
HVAC System (Heater, Ventilator and A/C)

1. Heater System
The heater control unit is located in the middle portion of the instrument panel.
The heater unit has mode doors and an air mix door. The intake unit has an intake door and a blow-
er motor. The heater unit and the intake unit are regulated by their control units.
Fresh outside air is introduced into the cabin through the center and side ventilators when the
blower fan is operated.
All models are equipped with front side window defrosters.
An optional filter is provided in front of the evaporator inlet.

A: LHD MODEL

S4H0001A

(1) Front defroster outlet (7) Fresh air (13) Intake door
(2) Side defroster outlet (8) Recirculated air (14) Heater core
(3) Center ventilator outlet (9) Ventilator door (15) Evaporator (A/C model)
(4) Side ventilator outlet (10) Heater door (16) Blower fan
(5) Front heater outlet (11) Defroster door
(6) Rear heater outlet (12) Air mix door A/C: Air conditioner

AC-2

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC01

HEATER SYSTEM
HVAC System (Heater, Ventilator and A/C)

B: RHD MODEL

S4H0548A

(1) Front defroster outlet (7) Fresh air (13) Intake door
(2) Side defroster outlet (8) Recirculated air (14) Heater core
(3) Center ventilator outlet (9) Ventilator door (15) Evaporator (A/C model)
(4) Side ventilator outlet (10) Heater door (16) Blower fan
(5) Front heater outlet (11) Defroster door
(6) Rear heater outlet (12) Air mix door A/C: Air conditioner

AC-3

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC02

SWITCH FUNCTIONS
HVAC System (Heater, Ventilator and A/C)

2. Switch Functions

S4H0002B

AC-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC03

MODE SELECTOR SWITCH AND AIR FLOW

HVAC System (Heater, Ventilator and A/C)

3. Mode Selector Switch and Air Flow

A: AIR FLOW

S4H0549A

AC-5

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC03

MODE SELECTOR SWITCH AND AIR FLOW

HVAC System (Heater, Ventilator and A/C)

B: AIR DISTRIBUTION RATIO

The following diagram shows air distribution for each position of the mode selector switch.
LHD model

BI-LEVEL DEF/HEAT

Mode selector switch position

G4H0030A

RHD model

S4H0550A

AC-6

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC03

MODE SELECTOR SWITCH AND AIR FLOW

HVAC System (Heater, Ventilator and A/C)

C: SYSTEM CONTROL FLOW

S4H0552A

AC-7

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC04

BLOWER SYSTEM
HVAC System (Heater, Ventilator and A/C)

4. Blower System
The blower relay is ready to be activated when the ignition switch is in the ON position. With the
ignition switch ON, placing the fan switch in any position other than OFF activates the relay, allow-
ing electric current to flow from the battery to the ground through the blower motor, the resistor,
and the selected fan switch contacts. The connected resistor(s) vary depending on the selected
position of the fan switch and cause the blower motor speed to change.
LHD model

H4H1097A

RHD model

S4H0529A

AC-8

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC05

AIR CONDITIONING CYCLE

HVAC System (Heater, Ventilator and A/C)

5. Air Conditioning Cycle

A: GENERAL
The refrigerant recirculates in the air conditioning system, flowing out of the compressor, passing
through the condenser, receiver drier and evaporator, and returning to the compressor.
The flow of refrigerant to the evaporator is controlled by an expansion valve located inside the
evaporator.
The compressor operates and stops repeatedly to maintain the evaporator temperature within a
specified range. When the evaporator temperature falls below the specified temperature, the ther-
mo-control amplifier stops the compressor operation. When the evaporator temperature rises
above the temperature, the thermo-control amplifier puts back the compressor into operation.
The refrigerant system is protected against excessively high or low pressures by a pressure
switch. If the system pressure rises or drops excessively, the pressure switch is activated to pre-
vent the compressor from operating.
LHD model

S4H0003C

(1) Condenser (6) High-pressure gas

(2) Compressor (7) Low-pressure gas
(3) Evaporator (8) High-pressure liquid
(4) Receiver drier (9) Low-pressure liquid
(5) Expansion valve (10) Refrigerant flow

AC-9

435
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC05

AIR CONDITIONING CYCLE

HVAC System (Heater, Ventilator and A/C)

RHD model

S4H0250A

(1) Compressor (8) Expansion valve

(2) Outside air (9) Blower motor
(3) Condenser (10) High-pressure gas
(4) Condenser fan motor (11) High-pressure liquid
(5) Evaporator (12) Low pressure liquid
(6) Receiver drier (13) Low-pressure gas
(7) Pressure switch

AC-10

436
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

6. Compressor
A: GENERAL
The compressor is a rotary type that has a rotor fitted with five radially movable vanes. The rotor
rotates together with the vanes in an elliptical cylinder. As the rotor rotates, the volume of each
closed space formed between two adjacent vanes (referred to as “cylinder chamber” in the follow-
ing description) decreases, so that the pressure of the refrigerant gas confined in the cylinder
chamber increases. In this way, the rotary compressor performs its function as a pump. The pump-
ing cycle consisting of suction, compression and discharge takes place 10 times during every
rotation of the rotor.
On the discharge side of the cylinder, a roll valve is provided that opens at a predetermined high
pressure. Air tightness between the rotor shaft and front head is ensured by the shaft seal. The
trigger valve incorporated in the front side block provides the function of applying back pressure
to the vanes. The compressor contains necessary quantity of compressor oil. The oil is distributed
to all the parts requiring lubrication and sealing by utilizing the discharge pressure of the refriger-
ant.

S4H0307A

(1) Front head (6) Vane (11) Shaft seal

(2) Side block (7) Rotor (12) Magnet clutch
(3) Rear head (8) Roll valve (13) Trigger valve
(4) Check valve (9) Cylinder
(5) Rear bearing (10) Front bearing

AC-11

437
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

B: FUNCTION
As the rotor rotates, the volume of each cylinder chamber changes. This creates the compressor’s
suction, compression and discharge functions as explained in the following:

1. SUCTION
Low-pressure gaseous refrigerant is forced out from the evaporator by rotation of the compressor.
It enters the low-pressure chamber in the rear head through the check valve. The refrigerant is then
drawn into the cylinder by rotation of the vane-fitted rotor through the two suction ports provided
in the rear side block. Air tightness of the cylinder chambers is maintained by the compressor oil.

B4H0745A

(1) Rotor (4) Rear head (7) Vane

(2) Refrigerant (5) Low-pressure chamber (8) Drive shaft
(3) Check valve (6) Rear side block

AC-12

438
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

2. COMPRESSION
Further rotation of the rotor after suction makes the volume of each cylinder chamber smaller, thus
compression occurs.

B4H0746A

(1) Drive shaft (2) Refrigerant

3. DISCHARGE
When the pressure of refrigerant in the cylinder chamber exceeds a predetermined pressure, the
roll valve opens to discharge the refrigerant through a pipe-shaped passage built in the front side
block into the high-pressure chamber in the front head. The gaseous refrigerant in the high-pres-
sure chamber is led to a baffle, which separates the compressor oil contained in the refrigerant
before it flows into the high-pressure piping.

B4H0747A

(1) Front head (4) Roll valve (7) High-pressure chamber

(2) Refrigerant (Discharging) (5) Front side block
(3) Refrigerant (High-pressure) (6) Pipe

AC-13

439
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

C: TRIGGER VALVE
This valve has a function of maintaining a proper level of pressure behind the vanes (vane back
pressure) such that they can move easily upon start of the compressor. The trigger valve is incor-
porated in the front side block and its end opens to a cavity called “K-ditch” that is provided in the
rotor side end of the side block. The valve consists of a check ball and a spring.
The vanes are prone to chatter if there is only small difference between the high- and low-pressur-
es. This condition typically occurs when the compressor is started. In such a condition, the spring
raises the ball to open the valve and allows the back pressure to act on the vanes, thereby ensuring
smooth operation.

S4H0308A

(1) K-ditch (3) Front head

(2) Check ball (4) Spring

1. WHEN COMPRESSOR STARTS OR WHEN LOAD IS LOW

When the compressor starts or when the load is low (the high-pressure level is low), the spring can
raise the check ball clear of its seat, so the trigger valve is opened. The pressure of the high-pres-
sure chamber then acts on the back end surface of each vane to prevent it from chattering.

B4H0749A

(1) High-pressure chamber (3) Vane

(2) Trigger valve (Open) (4) Rotor

AC-14

440
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

2. WHEN COMPRESSOR IS IN REGULAR OPERATION

When the pressure in the high-pressure chamber of the compressor increases, the pressure over-
comes the spring tension and pushes the check ball against its seat, so the trigger valve closes.
The oil port pressure coming through the side block is applied to the end surface of vane to main-
tain proper back pressure.

B4H0750A

(1) High-pressure chamber (3) Vane

(2) Trigger valve (Closed) (4) Rotor

D: CHECK VALVE
A check valve consisting of a spherical plate and spring is provided at the suction port of the rear
head. Immediately after the compressor has stopped, there is large difference between the high-
and low-pressures. This would cause reverse rotation of the compressor and consequent reverse
flow of refrigerant to the evaporator if no check valve is provided. Immediately after the compres-
sor has stopped, the high-pressure refrigerant forces the check valve plate upward and closes
the suction port to prevent flow of refrigerant from the high-pressure side to the low-pressure side.

B4H0751A

(1) Refrigerant suction port (3) Spring (5) Refrigerant

(2) Plate (4) Check valve

AC-15

441
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

E: LUBRICATION
The lubrication oil is collected at the bottom of the high-pressure chamber. The high-refrigerant
pressure in the chamber forces the oil upward through the oil passages in the front side block to
lubricate the front end of the rotor. The high-chamber pressure also forces the oil through the pas-
sages in the bottom of the cylinder to lubricate the rear end of the rotor. The oil that has lubricated
each end of the rotor enters the low-pressure chamber by the internal pressure of the compressor.
The oil contained in the gaseous refrigerant from the evaporator passes through the low-pressure
chamber and lubricates the rear bearing. The oil also passes through the passage in the drive
shaft and lubricates the front bearing and shaft seal before entering the suction port of the cylinder.
Since the pressure in the suction port of the cylinder is slightly lower than that in the low-pressure
chamber, the oil that has lubricated all the parts enters the suction port and is finally brought by
the refrigerant back to the high-pressure chamber.

B4H0752A

(1) Front bearing (4) Low-pressure chamber (7) High-pressure chamber

(2) Vane (5) Rotor (8) Shaft seal
(3) Rear bearing (6) Oil port

AC-16

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC06

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)

F: MAGNET CLUTCH
The magnet clutch serve to transmit engine power to the compressor module. It is built into the
compressor shaft. When current flow through the magnet clutch coil, the drive plate is attracted
so that the pulley and compressor shaft rotate as a module. When the compressor is not in use,
the pulley alone rotates freely.

B4H0169B

(1) Bearing (4) Drive shaft

(2) Magnet clutch coil (5) Clutch pulley
(3) Compressor (6) Drive plate

AC-17

443
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC07

CONDENSER
HVAC System (Heater, Ventilator and A/C)

7. Condenser
A: MECHANISM
1. LHD MODEL
The high-temperature and high-pressure gaseous refrigerant discharged from the compressor is
cooled down and converted into liquid by the condenser.
The condenser consists of tubes and radiating fins.
The heat of the refrigerant flowing through the condenser tubes is released into to the ambient air
which is caused to flow across the fins by the cooling fan.

S4H0498A
(1) Refrigerant inlet (High-pressure gaseous refrigerant)
(2) Refrigerant outlet (High-pressure liquid refrigerant)
(3) Refrigerant flow

2. RHD MODEL

S4H0499A
(1) Refrigerant inlet (High-pressure gaseous refrigerant)
(2) Refrigerant outlet (High-pressure liquid refrigerant)
(3) Fresh air

AC-18

444
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC08

RECEIVER DRIER
HVAC System (Heater, Ventilator and Air Conditioner)

8. Receiver Drier
A: MECHANISM
The amount of refrigerant necessary to circulate in the system varies with change in the heat load.
The receiver drier stores part of the liquid refrigerant until an increased heat load requires its use
again. The receiver drier also has the following functions:
1) It removes bubbles from the liquid refrigerant. (If bubbles are present, the refrigerant passing
through the expansion valve varies in quantity, temperature, and pressure, resulting in insufficient
cooling.)
2) It removes moisture from the refrigerant.
3) It removes foreign substance from the refrigerant.
4) It prevents the system components from breakage due to excessively high pressures as fol-
lows: If the pressure in the high-pressure system components (such as the condenser and receiv-
er drier) becomes abnormally high and the temperature rises beyond approximately 105°C
(221°F), the fusible plug in it melts, allowing refrigerant to be released into the atmosphere.
The receiver drier contains a strainer to remove foreign substance and desiccant to absorb mois-
ture from refrigerant.
1. LHD MODEL

S4H0500B

(1) Head block (6) Pressure switch

(2) Inlet (7) Strainer
(3) Outlet (8) Strainer cushion
(4) Inside pipe (9) Desiccant
(5) Body

AC-19

445
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC08

RECEIVER DRIER
HVAC System (Heater, Ventilator and A/C)

2. RHD MODEL

H4H1171B

(1) Head block (6) Retainer lower

(2) Outlet (7) Body
(3) Inlet (8) Inside pipe
(4) Retainer upper (9) Pressure switch
(5) Desiccant (10) Fusible plug

AC-20

446
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC09

PRESSURE SWITCH
HVAC System (Heater, Ventilator and A/C)

9. Pressure Switch
A: LHD MODEL
The pressure switch is located on the high-pressure line to the receiver drier. When an abnormally
high or low pressure occurs in the high-pressure line, the pressure switch turns OFF to stop opera-
tion of the compressor.
D When the pressure is abnormally low [177 kPa (1.8 kgf/cm2, 26 psi) or less]
The pressure switch turns OFF assuming that the refrigerant is lost due to leakage.
D When the pressure is abnormally high [2,940 kPa (30 kgf/cm2, 427 psi) or more]
The pressure switch turns OFF to prevent the system from being damaged.

B4H0172E

(1) Point terminal (4) Pressure guide

(2) Contact point (5) High-pressure disc spring
(3) Guide pin (6) Low-pressure disc spring

AC-21

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC09

PRESSURE SWITCH
HVAC System (Heater, Ventilator and A/C)

B: RHD MODEL
The pressure switch is located on the high-pressure line to the receiver drier. When an abnormally
high or low pressure occurs in the high-pressure line, the pressure switch turns OFF to stop opera-
tion of the compressor.
D When the pressure is abnormally low [176 kPa (1.8 kgf/cm2, 25.5 psi) or less]
The pressure switch turns OFF assuming that the refrigerant is lost due to leakage.
D When the pressure is abnormally high [2,648 kPa (27 kgf/cm2, 384 psi) or more]
The pressure switch turns OFF to prevent the system from being damaged.

H4H1172C

(1) Point terminal (5) O-ring

(2) Contact point (6) Guide pin
(3) Disc (7) Low-pressure disc spring
(4) High-pressure disc spring

AC-22

454
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC10

EVAPORATOR
HVAC System (Heater, Ventilator and Air Conditioner)

10. Evaporator
A: MECHANISM
Air pushed by the blower passes through the cooling fins and tubes of the evaporator. Since the
air is warmer than the refrigerant, the heat of air moves to the refrigerant through the fins and tubes.
As the low-pressure refrigerant moves through the evaporator, heat from the air causes the refrig-
erant to boil. By the time the refrigerant has passed through the evaporator, it becomes vapor.
Moisture in the air condenses to water drops as it moves around the tubes and fins of the evapora-
tor. Water and dirt are then discharged outside the vehicle through a drain hose.
The evaporator is a laminated type and consists of thin, rectangular aluminum plates arranged
in multiple layers and fins that are attached between them. During flow through the evaporator, the
state of the refrigerant changes as follows:
Misty refrigerant (very close to liquid form) from the expansion valve at a low-pressure, enters the
lower tube of the evaporator, where it soaks up heat from the compartment. The refrigerant boils
and vaporizes quickly due to the rapid heat exchange. Then the refrigerant is pushed upward by
the force of the bubble generated during the heat exchange and enter the upper tube. When it
reaches the upper tank, the refrigerant is in a thoroughly vaporized state.
The evaporator has a single tank, and its surface has been given the following treatments:
D Rustproof treatment
D Waterproof treatment
D Moldproof treatment
1. LHD MODEL

B4H1511A

(1) From receiver drier

(2) To compressor
(3) Misty refrigerant
(4) Vapor
(5) Expansion valve

AC-23

449
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC10

EVAPORATOR
HVAC System (Heater, Ventilator and A/C)

2. RHD MODEL

S4H0551A

(1) Outlet (7) Water droplets

(2) Inlet (8) Tube
(3) Cool air (9) Fin
(4) Warm air containing moisture (10) From receiver drier
(5) Easy-to-evaporate refrigerant (11) To compressor
(6) Vaporized refrigerant

AC-24

450
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC11

EXPANSION VALVE
HVAC System (Heater, Ventilator and A/C)

11. Expansion Valve

A: LHD MODEL
1. MECHANISM
The expansion valve is connected to both the evaporator inlet and outlet pipes. It converts high-
pressure liquid refrigerant which comes from the receiver drier to misty, low-pressure refrigerant
which is delivered to the evaporator. Being at low pressure and low temperature, this refrigerant
can easily evaporate in the evaporator and remove heat from the cabin air. The valve performs this
conversion by automatically controlling the flow rate of refrigerant according to the cooling ability
required by the heat load.
The refrigerant temperature is sensed by the temperature sensing element located in the low-
pressure refrigerant passage of the expansion valve, and the flow rate of the refrigerant is con-
trolled by changing the lift of the valve ball located in the high-pressure passage.

H4H1123B

(1) Temperature sensing element (5) To evaporator (Low-pressure)

(2) Diaphragm (6) Valve ball
(3) From evaporator (Low-pressure) (7) To compressor
(4) Shaft (8) From receiver drier

AC-25

451
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC11

EXPANSION VALVE
HVAC System (Heater, Ventilator and A/C)

2. FUNCTION
When the heat load to the air conditioning system increases, the refrigerant temperature at the
evaporator outlet rises and therefore the pressure P1 around the temperature sensing area in-
creases. As this pressure P1 becomes higher than the sum of the evaporator outlet (low-pressure
side) pressure P2 and the spring force F (P1 > P2 + F), the diaphragm is pressed down, moving
the valve ball connected to the diaphragm clear of its seat. This increases the flow of the refriger-
ant.
When the heat load is small, the action of the valve’s inner elements is contrary to the above; the
valve ball closes and the flow of the refrigerant decreases.

H4H1124

AC-26

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC11

EXPANSION VALVE
HVAC System (Heater, Ventilator and A/C)

B: RHD MODEL
1. MECHANISM
The expansion valve is located at the inlet of the evaporator. As high-pressure, high-temperature
refrigerant from the receiver drier passes through the expansion value’s needle valve hole, it rapid-
ly expands and changes from a liquid into a low-temperature, low-pressure vapor. The expansion
valve also meters refrigerant into the evaporator in accordance with the thermal load.
The expansion valve consists of a heat sensitive tube, diaphragm, valve ball, springs and other
components.
The heat sensitive tube is kept in contact with the evaporator outlet pipe so that it can convert
change in the pipe’s temperature into change in the pressure that acts on the upper chamber of
the diaphragm in the way described below.
The heat sensitive tube contains the same refrigerant as that used in the air conditioner system
and inside pressure of the heat sensitive tube varies as the evaporator outlet temperature
changes.
The valve ball moves as the diaphragm deforms, so the opening of the expansion value is deter-
mined by the downward pressure and upward pressure acting on the diaphragm.

S4H0190B

(1) Diaphragm (5) Capillary tube

(2) Valve ball (6) Heat sensitive tube
(3) Spring (7) Outlet
(4) Adjust screw (8) Inlet

AC-27

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC11

EXPANSION VALVE
HVAC System (Heater, Ventilator and A/C)

2. FUNCTION
The expansion valve adjusts refrigerant flow using the valve ball whose position is determined by
the balance of the heat sensitive tube inside pressure P1 that is acting downward on the dia-
phragm and the combination of evaporator refrigerant pressure P2 and spring pressure F that is
acting upward on the diaphragm (P1 = P2 + F).

S4H0530A

(1) Heat sensitive tube

(2) Evaporator
(3) Refrigerant flow
(4) Valve ball

AC-28

454
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC11

EXPANSION VALVE
HVAC System (Heater, Ventilator and A/C)

Under large thermal load

When the thermal load is large and the evaporator temperature is high, the heat sensitive tube tem-
perature and pressure are high (P1 > P2 + F), pushing the diaphragm down with a large force.
Since the ball valve is moved in the opening direction by the force, flow rate of refrigerant into the
evaporator increases so that the cooling capacity of the system increases.

S4H0531A

(1) Heat sensitive tube

(2) Evaporator
(3) Refrigerant flow
(4) Valve ball

AC-29

455
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC11

EXPANSION VALVE
HVAC System (Heater, Ventilator and A/C)

Under small thermal load

When the thermal load is small, the evaporator outlet temperature is low. Since the heat sensitive
tube pressure is also low, the pressure pushing the diaphragm downward is smaller than the pres-
sures pushing it upward (P1 < P2 + F). As a result, the valve ball is moved in the closing direction,
decreasing the flow rate of refrigerant into the evaporator. The cooling capacity of the system now
decreases.

S4H0532A

(1) Heat sensitive tube

(2) Evaporator
(3) Refrigerant flow
(4) Valve ball

AC-30

456
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC12

COMPRESSOR CLUTCH “ON” DELAY SYSTEM

HVAC System (Heater, Ventilator and A/C)

12. Compressor Clutch “ON” Delay System

When the A/C switch and fan switch are turned ON, a signal is sent to the engine control module.
The engine control module then judges whether the engine is in operation. If the engine is operat-
ing, the engine control module activates the A/C relay. The maximum clutch “ON” delay times is
0.8 seconds after the A/C relay is activated.

Pressure switch

B4H1832B

AC-31

457
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. AC13

COMPRESSOR CONTROL SYSTEM

HVAC System (Heater, Ventilator and A/C)

13. Compressor Control System

A: GENERAL
1) When the A/C switch and fan switch are turned ON, the A/C relay is activated. The compressor
starts operating, and then the main and sub fans also operate.
2) The thermo control amplifier, when activated, disengages the compressor clutch and the main
and sub fans.
3) When the pressure switch turns on, the compressor clutch is disengaged and the main and
sub fans also stop.

B: THERMO CONTROL AMPLIFIER

The thermo control amplifier disconnects the magnet clutch circuit to prevent the evaporator from
becoming frosted when the temperature of the evaporator fin drops close to 3°C (37°F). When the
limit temperature is reached, the thermistor (located on the evaporator fin) interrupts the base cur-
rent of the amplifier. This deactivates the A/C relay, which in turn disconnects the magnet clutch
circuit.
Pressure sw

B4H1833B

AC-32

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COMPRESSOR CONTROL SYSTEM

HVAC System (Heater, Ventilator and A/C)

C: ACCELERATION CUT SYSTEM

The A/C switch turns the air conditioning system ON and OFF. The on-off signals from the switch
are transmitted to the engine control module (ECM).
When the ECM receives a full-throttle signal from the throttle sensor during compressor operation,
it deactivates the A/C relay to interrupt electric current to the compressor magnet clutch. This pre-
vents the degradation of acceleration performance. The A/C relay is in the main fuse box located
on the left side of the engine compartment.

Pressure sw

B4H1834B

D: IDLE SPEED CONTROL

The idle air control solenoid valve increases the engine idling speed when the compressor is in
operation.
The engine control module activates the idle air control solenoid valve when it receives an A/C
switch ON signal so that necessary by-pass air is introduced into the throttle body to ensure proper
idling speed for an increased engine load.

Idle air control

solenoid valve

B4H0181A

AC-33

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COMPRESSOR CONTROL SYSTEM

HVAC System (Heater, Ventilator and A/C)

E: FAN CONTROL
The main fan and sub fan are switched ON and OFF according to the operating modes as shown
in the following table.
1. NON-TURBO MODEL
Engine coolant temperature
Lower than 95°C Between 95 and 99°C Higher than 100°C
Vehicle speed Compressor (203°F) (203 and 210°F) (212°F)
Operation of radiator fans Operation of radiator fans Operation of radiator fans
Main fan Sub fan Main fan Sub fan Main fan Sub fan
Lower than 19 km/h OFF OFF OFF ON OFF ON ON
(12 MPH)
ON ON ON ON ON ON ON
Between 20 and 69 km/h OFF OFF OFF ON OFF ON ON
(12 and 43 MPH)
ON ON ON ON ON ON ON
Between 70 and 89 km/h OFF OFF OFF OFF OFF ON ON
(43 and 55 MPH)
ON ON OFF ON ON ON ON
Higher than 90 km/h OFF OFF OFF OFF OFF ON ON
(56 MPH)
ON OFF OFF ON OFF ON ON

2. TURBO MODEL
Engine coolant temperature
Lower than 95°C Between 95 and 99°C Higher than 100°C
Vehicle speed Compressor (203°F) (203 and 210°F) (212°F)
Operation of radiator fans Operation of radiator fans Operation of radiator fans
Main fan Sub fan Main fan Sub fan Main fan Sub fan
Lower than 19 km/h OFF OFF OFF ON OFF ON ON
(12 MPH)
ON ON ON ON ON ON ON
Between 20 and 69 km/h OFF OFF OFF ON OFF ON ON
(12 and 43 MPH)
ON ON ON ON ON ON ON
Between 70 and 106 km/h OFF OFF OFF OFF OFF ON ON
(43 and 66 MPH)
ON ON OFF ON ON ON ON
Higher than 107 km/h OFF OFF OFF OFF OFF ON ON
(67 MPH)
ON OFF OFF ON OFF ON ON

AC-34

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AIRBAG SYSTEM AB
Page
1. Airbag System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

AB

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AIRBAG SYSTEM
Airbag System

1. Airbag System
A: INSTALLATION

S5H0328B

(1) Front sub sensor (7) Side airbag sensor

(2) 7-pin connector (Yellow) (8) 4-pin connector (Yellow)
(3) 2-pin connector (Yellow) (9) Airbag control module
(4) Airbag module (Driver) (10) 28-pin connector (Yellow)
(5) 12-pin connector (Yellow) (11) Airbag module (Side)
(6) Airbag module (Passenger)

AB-2

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AIRBAG SYSTEM
Airbag System

B: FUNCTION
1. FRONT AIRBAGS
The airbag system is provided as a driver and front passenger restraint system supplementary
to the seat belts. When an impact greater than a set level is applied to the front of the vehicle, the
sensors generate an electrical pulse to inflate the airbags in the airbag modules, thus preventing
the driver’s and passenger’s upper bodies from directly hitting against the steering wheel, instru-
ment panel and/or windshield.

Front sub sensor Front

sub sensor

D Collision

D Front sub sensor,

electric sensor and
safety sensor detect
an impact greater
than the set level.
↓
D Inflators are ignited.
↓
D Gas is generated.
↓
D Airbag inflation com-
pletes.
↓
D Gas is discharged.

D Airbags deflate.

B5H0504B

AB-3

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AIRBAG SYSTEM
Airbag System

2. SIDE AIRBAGS
The side airbags provide the driver and front passenger with a restraint supplementary to that by
the seat belts in the event of a side-on collision. When an impact greater than the set level is applied
to either side of the vehicle, the relevant side airbag sensor sends an ignition signal to the corre-
sponding airbag control module. The side airbag module operates to inflate the airbag, thus re-
ducing the shock inflicted in the outside upper body (chest) of the driver or front passenger.

D Collision

D Side airbag sensor detects

an impact greater than the
set level.
↓
D Inflator is ignited.
↓
D Gas is generated.
↓
D Airbag inflation completes.
↓
D Gas is discharged.

D Airbag deflates.

B5H0505B

AB-4

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CONSTRUCTION
Airbag System

2. Construction
A: GENERAL
D The airbag system consists of an airbag control module, left and right front sub sensors, an elec-
tric sensor and safety sensor built into the control module, driver’s and passenger’s airbag mod-
ules each containing an inflator and airbag, and side airbag sensors and modules each contain-
ing an inflator and airbag (Side airbag equipped model).
D FRONT AIRBAG SYSTEM:
A frontal impact exceeding the set level causes the safety sensor, electric sensor and one or both
front sub sensors to input impact signals to the CPU. The CPU determines whether the airbags
should be inflated or not based on these signals.
D SIDE AIRBAG SYSTEM:
Input of a side impact signal showing shock energy greater than the set level causes the airbag
on the corresponding side to inflate.

Front sub Front sub

sensor (LH) sensor (RH)

B5H0552A

AB-5

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CONSTRUCTION
Airbag System

B: AIRBAG CONTROL MODULE

The airbag control module is installed in front of the front floor tunnel. It detects the vehicle’s decel-
eration by receiving electrical signals from its inside safety and electric sensors as well as the front
sub sensors and judges whether to inflate the airbags. This control module has a built-in self-diag-
nosis function. If a fault occurs inside the system, it lights up the airbag warning light in the com-
bination meter. The fault data is stored in the module. A back-up power supply is provided for pos-
sible damage to the battery during an accident, and a boosting circuit is built into the module in
case of a battery voltage drop.

S5H0010

C: FRONT SUB SENSOR

One front sub sensor is installed on each side, in front of the front wheel apron wall. The front sub
sensor is a pendulum type sensor. If the sensor receives a frontal impact exceeding a certain limit,
the mass in the sensor rotates forward to turn the switch ON.

Switch contacts

B5H0507B

AB-6

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CONSTRUCTION
Airbag System

D: AIRBAG SENSOR
The safety sensor and electric sensor are incorporated into the airbag control module and the side
airbag sensors.
The safety sensor is also a pendulum type sensor. If the sensor receives a frontal or side impact
exceeding a certain limit, the mass in the sensor moves in the direction opposite to the impact
direction to turn the switch ON.
The electric sensor consists of a semiconductor type sensor which senses the deceleration
caused by collision in terms of change in the electrical resistance of the impact sensing circuit.

Switch contacts

H5H0685B

AB-7

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CONSTRUCTION
Airbag System

E: AIRBAG MODULE
1. FRONT AIRBAG
The driver’s airbag module is located at the center of the steering wheel and the passenger’s air-
bag module is located at upper portion of instrument panel. Each module contains an airbag and
an inflator. If a collision occurs, the inflator produces a large volume of gas to inflate the airbag in
a very short time.
Driver’s module Passenger’s module

B5H0823B

(1) Airbag (4) Inflator (Passenger)

(2) Inflator (Driver) (5) Steering support beam
(3) Airbag module lid

2. SIDE AIRBAG
A side airbag module is located at the outer side of each front seat backrest, and it contains an
airbag and an inflator.
If a side-on collision occurs, the inflator produces a large volume of gas to inflate the airbag in a
very short time.

B5H0508A

AB-8

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CONSTRUCTION
Airbag System

F: AIRBAG CONNECTORS
1. DESCRIPTION
The airbag system uses connectors with a double lock mechanism and an incomplete coupling
detection mechanism for enhanced reliability. If coupling is incomplete, the airbag warning light
comes on in the combination meter.

AB-9

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CONSTRUCTION
Airbag System

2. AIRBAG HARNESS-TO-AIRBAG HARNESS CONNECTOR

NF0304

Disconnection:

NF0305

Connection:
Insert the male side connector half into the other until a “click” is heard.

AB-10

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CONSTRUCTION
Airbag System

3. AIRBAG HARNESS-TO-BODY HARNESS CONNECTOR

Disconnection:
Press the lever (A) to let the green lever (B) pop out. This unlocks the double lock mechanism. Then
separate the connector halves by pulling them apart while pressing the lever (A).
Connection:
Insert the male side connector half into the other until a “click” is heard, then push in the green lever
(B) until a “click” is heard. This engages the double lock mechanism.

B5H0841A

4. FRONT SUB SENSOR AND SIDE AIRBAG SENSOR CONNECTORS

Disconnection:
Holding the outer part (A), pull the connector in the direction of the arrow.

NF0132

Connection:
Holding the inner part, push the connector into the socket carefully until a click is heard.
Do not hold the outer part (A) as it moves back during connection of the connector.

NF0133

AB-11

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CONSTRUCTION
Airbag System

G: STEERING ROLL CONNECTOR

The steering roll connector is located between the steering column and steering wheel. The con-
nector contains a spirally wound flat cable. The cable can follow rotational movements of the steer-
ing wheel and ensures connection between the airbag module in the steering wheel and the air-
bag harness through which electrical signals are transmitted from the airbag control module.

S5H0013A

H: AIRBAG WARNING LIGHT

The airbag warning light is located inside the combination meter. It illuminates if a poor connection
in the airbag circuit occurs, or if the airbag control module detects an abnormal condition. When
the airbag system is normal, this light comes on when the ignition switch is turned ON and then
goes out about 7 seconds later.

S5H0014

I: WIRE HARNESS
The wire harness of the airbag is entirely covered with a yellow protective tube, and can easily be
distinguished from the other systems’ harnesses.

AB-12

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CONSTRUCTION
Airbag System

J: LOCATIONS OF WARNING AND CAUTION LABELS

S5H0417A

H5H0947A

AB-13

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CONSTRUCTION
Airbag System

MEMO

AB-14

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SEAT BELT SYSTEM SB

Page
1. Seat Belt ..............................................................................2

SB

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SB01

SEAT BELT
Seat Belt System

1. Seat Belt
A: ADJUSTABLE SHOULDER BELT ANCHOR
Each front seat belt system has an adjustable shoulder belt anchor which allows the occupant to
select the most appropriate anchor height from among the four positions in a 75 mm (2.95 in)
range.

S5H0370A

B: REAR CENTER THREE-POINT TYPE SEAT BELT (WAGON)

A three-point type seat belt is available for the center seating position of the rear seat.
The retractor for the seat belt is installed on the ceiling at the rear right of the cabin.

S5H0372A

(1) Retractor
(2) Bracket

SB-2

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SEAT BELT
Seat Belt System

C: SEAT ANCHORED INNER BELT

The front inner belt (buckle stalk) is attached to the front seat rather than to the floor. This keeps
the position of the occupant relative to the front inner belt always constant even when the front seat
is moved for adjustment.
When an impact is applied to the occupant in a collision, the inner belt is pulled together with the
upper hook in the direction of the arrow to engage the upper hook with the lower hook. As a result,
the impact load is transmitted to the vehicle body and dispersed.

B5H0945A

(1) Inner belt

(2) Upper hook
(3) Lower hook

SB-3

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SEAT BELT
Seat Belt System

D: PRETENSIONER
1. CONSTRUCTION
The driver’s and front passenger’s seat belts are equipped with a seat belt pretensioner.
There is a pretensioner sensor in each seat belt retractor assembly. If the sensor detects a force
exceeding the predetermined strength during a frontal or front-angled collision, the seat belt is
rewound quickly by the retractor so that slack in the belt is taken up and the belt restrains effective-
ly the occupant. Once the pretensioner has been activated, the retractor remains locked.

S5H0287B

(1) Belt (3) Rack

(2) Retractor (4) Pinion gear

SB-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. SB01

SEAT BELT
Seat Belt System

2. CAUTION LABEL LOCATION

S5H0371A

(1) Caution label

E: AUTOMATIC RETRACTOR
When each of the rear seat belts (for right, left and center seating positions) are drawn out com-
pletely, its retractor is placed in the automatic locking mode which is used when installing a child
restraint system. In this mode, the belt can be retracted but cannot be extended. When the belt
is retracted to a certain length, this mode is cancelled and normal operation is restored.

Normal mode Automatic locking mode

Belt can be Belt can be retracted but

extended and cannot be extended.
retracted.

Automatic locking Normal mode to

mode to normal mode automatic locking
changeover mode changeover

B5H0328A

SB-5

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SEAT BELT
Seat Belt System

F: ENERGY ABSORBING EMERGENCY LOCKING RETRACTOR

1. MECHANISM
D The energy absorbing retractor consists of a plate, lower plate, slide plate, torsion bar and
clamp.
D The energy absorbing retractor releases part of the tension in the belt when a load exceeding
the predetermined level is applied to the belt in a collision. If the vehicle is involved in a collision,
the retractor assembly must always be replaced with a new one regardless of its severity, since
the internal parts may be deformed.

2. OPERATION
If the belt is pulled by a force exceeding the predetermined level, the retractor mechanism locks
and prevents the belt from being unwound. If a force exceeding the preset level continues being
applied further, the slide plate in the retractor moves along with the belt locking clamp and the belt,
causing itself to be deformed gradually. The tension in the belt is eased through this process and,
after this, a controlled restraint is assured by means of a torsion bar located at the center of the
roller.

S5H0327A

(1) Plate (4) Clamp

(2) Belt (5) Torsion bar
(3) Lower plate (6) Slide plate

SB-6

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WIPER AND
WASHER SYSTEMS WW WW

Page
1. Front Wiper and Washer ............................................................ 2
2. Rear Wiper and Washer ............................................................ 3

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FRONT WIPER AND WASHER

Wiper and Washer Systems

1. Front Wiper and Washer

A: DESCRIPTION
1. FRONT WIPER
1) The front wiper is of a tandem type featuring wide wiping area. The blade is installed to the arm
by means of U-hook joint to improve serviceability.
2) The front wiper operates in the HI and LOW speed modes and the INTERMITTENT mode.
The operation modes can be selected by turning the wiper switch incorporated in the combination
switch.
3) In the INTERMITTENT mode, the intermittent unit installed behind the combination switch con-
trols the front wiper operation interval.

2. FRONT WASHER SYSTEM

1) The washer system consists of a washer tank, motor and pump unit and a pair of nozzles.
2) The washer tank is installed at the front of the strut mount on the left side of the engine compart-
ment.
3) The washer motor and pump unit is installed at the bottom of the washer tank.
4) The washer nozzles are installed on the hood. Each nozzle has two spray holes.

WW-2

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REAR WIPER AND WASHER

Wiper and Washer Systems

2. Rear Wiper and Washer

A: DESCRIPTION
1. REAR WIPER
1) The rear wiper operates over a 136-degree angle.
2) The wiper blade is attached to the arm by means of a U-hook joint in the same way as with the
front wiper blade.
3) The rear wiper operates intermittently at a 10-second interval.

2. REAR WASHER SYSTEM

1) The same washer tank is shared by the front and rear washer systems.
2) The washer motor and pump unit is installed at the bottom of the washer tank, adjacent to the
front washer’s unit.
3) The washer nozzle is installed on the upper portion of rear gate panel. The nozzle has two spray
holes.

WW-3

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REAR WIPER AND WASHER

Wiper and Washer Systems

MEMO

WW-4

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. GW00

GLASS/WINDOWS/MIRRORS GW
Page
1. Power Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 GW
2. Windshield Wiper Deicer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

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POWER WINDOW
Glass/Windows/Mirrors

1. Power Window
A: CONSTRUCTION
D The power window system consists of regulator motors and switches for individual doors, relays
and a circuit breaker unit.
D Each door window opens/closes by pushing down/pulling up the switch.
D Only the driver’s door window switch has a 2-stage mechanism:
D When the switch is pushed lightly and held in the pushed position, the window continues to
lower until the switch is released.
D When the switch is pushed down fully, the window lowers to the end position automatically.
NOTE:
For the sake of safety, the power window system is designed to operate only when the ignition
switch is in the ON position.

B: CIRCUIT DIAGRAM

NF0222

GW-2

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WINDSHIELD WIPER DEICER

Glass/Windows/Mirrors

2. Windshield Wiper Deicer

A: CONSTRUCTION
The wiper deicer system is activated when the wiper deicer switch is pressed with the ignition
switch turned ON. It heats the lower part of the windshield with a heater wire to melt the ice that
blocks the wiper blades.
The system turns off automatically in 15 minutes after the wiper deicer switch is turned ON.

Windshield

Printed ceramic

Wiper deicer
heater wire

Printed ceramic
Heating area of wiper deicer

B6H0857C

B: CIRCUIT DIAGRAM

B6H0858

GW-3

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WINDSHIELD WIPER DEICER

Glass/Windows/Mirrors

MEMO

GW-4

488
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BS00

BODY STRUCTURE BS
Page
1. Steering Support Beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Quietness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Body Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 BS
5. Anti Chipping Coat (ACC) Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Sealer Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Anti-rust Wax (Bitumen Wax) Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8. Polyvinyl Chloride (PVC) Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
9. Hot Wax Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
10. Rustproof Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11. Galvanized Sheet Metal Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
12. Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

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STEERING SUPPORT BEAM

Body Structure

1. Steering Support Beam

A steering support beam (A) is provided between the left and right front pillars for reinforced sup-
port of the steering column. It also minimizes vibration of the steering column and limits its exten-
sion to a minimum in the event of a collision.

S5H0022B

BS-2

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BS02

QUIETNESS
Body Structure

2. Quietness
Silencers, dual-wall panels, sound-absorbing materials, etc. are utilized in conjunction with a high-
rigidity and vibration/noise-proof body structure in order to ensure quietness of the passenger
compartment.

A: SILENCERS
Silencers (= asphalt sheets) minimize transmission of noise/vibration into the passenger compart-
ment.

B: DUAL-WALL TOEBOARD
The toeboard is a dual-wall design consisting of an asphalt sheet placed between two steel panels
to reduce the transmission of noise and vibration from the engine compartment to the passenger
compartment.

S5H0023B

(1) Dual-wall toeboard

(2) Silencers

BS-3

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BODY SEALING
Body Structure

3. Body Sealing
A: SEALED PARTS
All gauge holes and other holes used during the body manufacturing process are plugged to pre-
vent entry of water and dust.
Any time the vehicle body has been repaired, the affected holes should be properly plugged with
the use of the specified plugs.

BS-4

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PAINTING
Body Structure

4. Painting
A: SPECIFICATION
Color name Color code
PURE WHITE 8J5 (51E / Unpainted)
RED MICA (M) 9R6 (94H / Unpainted)
ROYAL SILVER (M) 8J6 (792 / Unpainted)
GREEN (M) 8G2 (64C / Unpainted)
DEEP BLUE MICA 9R7 (95H / Unpainted)
PURE WHITE / PURE WHITE 51E (51E / 51E)
ROYAL SILVER (M) / ROYAL SILVER (M) 792 (792 / 792)
BLACK MICA / BLACK MICA 47A (47A / 47A)
RED MICA (M) / RED MICA (M) 94H (94H / 94H)
ROYAL SILVER (M) / WARM GRAY OPAL 8L8 (792 / 89N)
GREEN (M) / WARM GRAY OPAL 9R1 (64C / 89N)
BLACK MICA / WARM GRAY OPAL 8K9 (47A / 89N)
PURE WHITE / WARM GRAY OPAL 8K2 (51E / 89N)
RED MICA (M) / WARM GRAY OPAL 9R3 (94H / 89N)
DEEP BLUE MICA / WARM GRAY OPAL 9R4 (95H / 89N)
CHAMPAGNE GOLD (M) / WARM GRAY OPAL 9R2 (93H / 89N)

(M): Metallic

B: PAINT FILM STRUCTURE

Translucent
colored layer

Color base
layer

Intermediate
paint layer

Transparent
clear layer

Color base
layer

Intermediate
paint layer

B5H0614I

BS-5

493
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ANTI CHIPPING COAT (ACC) APPLICATION

Body Structure

5. Anti Chipping Coat (ACC) Application

S5H0373

BS-6

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SEALER APPLICATION
Body Structure

6. Sealer Application
A: ENGINE COMPARTMENT

S5H0389A

(1) Sealer

B: ENGINE HOOD

S5H0025B

(1) Sealer

BS-7

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SEALER APPLICATION
Body Structure

C: DOOR

S5H0026B

(1) Sealer

D: REAR GATE

S5H0027B

(1) Sealer

BS-8

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ANTI-RUST WAX (BITUMEN WAX) APPLICATION

Body Structure

7. Anti-rust Wax (Bitumen Wax) Application

S5H0028

BS-9

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ANTI-RUST WAX (BITUMEN WAX) APPLICATION

Body Structure

H5H0679B

(1) Cover
(2) Fuel filler pipe

H5H0677B

(3) Propeller shaft

(4) Exhaust pipe

S5H0029B

(5) Toeboard
(6) Toeboard reinforcement

BS-10

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POLYVINYL CHLORIDE (PVC) APPLICATION

Body Structure

8. Polyvinyl Chloride (PVC) Application

S5H0030

S5H0031

BS-11

499
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BS09

HOT WAX APPLICATION

Body Structure

9. Hot Wax Application

S5H0374A

BS-12

500
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BS09

HOT WAX APPLICATION

Body Structure

A: REAR AND FRONT END SECTIONS OF ENGINE HOOD

Engine hood rear end inner surface

Engine hood front end inner surface

Bracket
Reinforcement

H5H0779B

B: FRONT BULKHEAD AND PITCHING STOPPER BRACKET

Bulkhead

Pitching stopper bracket

Toeboard center reinforcement

Pitching stopper bracket
inner surface

H5H0780B

C: RADIATOR LOWER PANEL

Lower frame inner surface

Lower frame A

Lower frame B

H5H0781B

BS-13

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HOT WAX APPLICATION

Body Structure

D: LOWER SECTION OF FRONT PILLAR

Outer side panel

Side sill inner panel

S5H0033A

E: SIDE SILL INNER AND SIDE DOOR LOWER PANELS

Side door lower panel

Side sill inner panel

S5H0034B

F: REAR GATE UPPER END INNER SURFACE

Rear gate upper end inner surface

H5H0785C

BS-14

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HOT WAX APPLICATION

Body Structure

G: REAR GATE LOWER END

Door inner panel

Door outer panel

H5H0786C

H: REAR QUARTER FRONT OUTER PANEL

Rear quarter front outer panel Rear arch inner panel

H5H0787C

I: REAR QUARTER OUTER PANEL

Rear arch inner surface

Rear quarter outer panel

H5H0788C

BS-15

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HOT WAX APPLICATION

Body Structure

J: SIDE FRAME INNER SURFACE, UPPER SIDE FRAME AND UPPER SIDE
FRAME FLANGE
Upper side frame flange
Upper side frame inner surface

Upper side frame

Front wheel apron Side frame inner surface

upper surface

Front floor side frame

Frame reinforcement
H5H0722D

K: REAR CROSS MEMBER BRACKET

Front floor panel

Rear cross member

bracket

Side frame reinforcement

Rear floor side frame
H5H0790C

L: CROSS MEMBER A

Cross member A reinforcement

S5H0035A

BS-16

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HOT WAX APPLICATION

Body Structure

M: CROSS MEMBER B INNER PORTION

Rear floor frame

H5H0792C

N: TOEBOARD REINFORCEMENT INNER SURFACE

H5H0793C

O: LOWER END INNER SURFACE OF REAR QUARTER OUTER PANEL

Rear quarter outer panel

Rear floor side panel

H5H0794C

BS-17

505
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HOT WAX APPLICATION

Body Structure

P: ENGINE HOOD HINGES

Engine hood

H5H0723D

Q: REAR GATE HINGES

S5H0036A

R: CENTER PILLAR LOWER AND INSIDE

Outer side panel

Side sill center reinforcement

Side sill reinforcement

Side sill inner panel

S5H0037A

BS-18

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HOT WAX APPLICATION

Body Structure

S: FRONT AND REAR DOORS

Front doors Rear doors

H5H0797C

BS-19

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RUSTPROOF PARTS
Body Structure

10. Rustproof Parts

S5H0375A

(1) Mud guard (5) Rear door side garnish

(2) Front fender side garnish (6) Rear quarter side garnish
(3) Front door side garnish (7) Wheel arch molding
(4) Side sill garnish (8) Fuel tank guard

BS-20

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GALVANIZED SHEET METAL APPLICATION

Body Structure

11. Galvanized Sheet Metal Application

: Galvanized on both sides

S5H0376A

BS-21

509
 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. BS12

VENTILATION
Body Structure

12. Ventilation
A: AIR OUTLET PORT

S5H0040A

(1) Air outlet port (3) Air flow

(2) Rear quarter panel (4) Rear bumper

BS-22

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INSTRUMENTATION/DRIVER INFO IDI

Page
1. Combination Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Outside Air Temperature Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

IDI

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COMBINATION METER
Instrumentation/Driver Info

1. Combination Meter
A: WARNING AND INDICATOR LIGHTS

S6H0422C

(1) Rear differential oil temperature warning light (Turbo model)

This light illuminates when the rear differential oil temperature exceeds 150°C (302°F).
(2) ABS warning light
This light illuminates when a fault occurs in any electrical component of the ABS (Anti-lock Brake System).
(3) AIR BAG system warning light
This light illuminates when a fault occurs in the airbag system.
(4) Brake fluid level warning / parking brake indicator light
This light illuminates when the fluid level in the brake reservoir tank lowers below the specified level and/or when the parking
brake is applied.
(5) AT oil temperature warning light
This light illuminates when the ATF temperature exceeds 150°C (302°F).
(6) Charge indicator light
This light illuminates when a fault occurs in the charging system while the engine is running.
(7) CHECK ENGINE warning light
This light illuminates when a fault occurs in the MFI (Multiple point Fuel Injection) system.
(8) Oil pressure warning light
This light illuminates when the engine oil pressure decreases below 14.7 kPa (0.15 kgf/cm2, 2.1 psi).
(9) POWER indicator light
This light blinks when a fault occurs in the AT control system.

IDI-2

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COMBINATION METER
Instrumentation/Driver Info

If everything is normal, the warning and indicator lights should be ON or OFF as shown below ac-
cording to ignition switch positions.
Warning/Indicator light Ignition switch position
LOCK/ACC ON ST While engine is running
(1) Rear differential oil temperature OFF ON ON OFF
(2) ABS OFF *3 ON OFF
(3) AIR BAG OFF *2 ON *2
(4) Brake fluid level / parking brake OFF ON ON *4
(5) AT oil temperature OFF ON ON OFF
(6) Charge OFF ON ON OFF
(7) CHECK ENGINE OFF *1 ON OFF
(8) Oil pressure OFF ON ON OFF
(9) POWER OFF ON ON OFF

*1:This light comes ON before engine starts, and stays OFF after engine has started.
*2:This light comes ON for about 7 seconds, and then goes out.
*3:This light comes ON for about 2 seconds, and then goes out.
*4:This light comes ON when the parking brake is applied.

IDI-3

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COMBINATION METER
Instrumentation/Driver Info

B: TELLTALE (GRAPHIC MONITOR)

S6H0422B

(1) AWD LO indicator light

This light illuminates when the dual-range select lever is in the LO position.
(2) Seat belt warning light
This light stays illuminated for about 6 seconds after the ignition switch has been turned ON if the driver’s seat belt is not
fastened.
(3) FWD indicator light
This light illuminates when the center differential locks (with the fuse installed in the center differential locking circuit).
(4) Turn signal indicator light
This light blinks in unison with the corresponding turn signal lights when the turn signal switch is operated.
(5) Headlight beam indicator light
This light illuminates when the headlights are in the high-beam position.
(6) Immobiliser indicator light
This light illuminates when the immobiliser system is armed with the ignition switch is turned to the “ACC” or “OFF” position.
(7) Low fuel warning light
This light illuminates when the quantity of the fuel remaining in the fuel tank has decreased to 8.0 liters (2.1 US gal, 1.8
lmp gal or smaller).
(8) Door open warning light
This light illuminated when one or more doors and/or rear gate are not completely closed.
(9) HOLD indicator light
This light illuminates when the automatic transmission is in the HOLD mode.
(10) POWER indicator light
This light illuminates when the automatic transmission is in the POWER mode.

IDI-4

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COMBINATION METER
Instrumentation/Driver Info

If everything is normal, the telltales should be ON, OFF or in other states as shown below according
to ignition switch positions.
Telltale light Ignition switch position
LOCK/ACC ON ST While engine is
running
(1) AWD-LO D Low range OFF ON ON ON
D High range OFF OFF OFF OFF
(2) Seat belt D Saudi model OFF *3 *3 *3
D Australia mod- OFF *5 *5 *5
el
(3) FWD D FWD OFF ON ON ON
D AWD OFF OFF OFF OFF
(4) Turn signal OFF Blink Blink Blink
(5) Headlight beam D High beam OFF ON ON ON
D Low beam OFF OFF OFF OFF
(6) Immobiliser *6 OFF OFF OFF
(7) Low fuel OFF *1 *1 *1
(8) Door open D Open ON ON ON ON
D Shut OFF OFF OFF OFF
(9) HOLD OFF *2 *2 *2
(10) POWER OFF *4 *4 *4

*1:The light illuminates when quantity of the fuel remaining in the tank has decreased to 8.0 liters (2.1 US gal, 1.8 lmp gal or smaller).
*2: The light illuminates when the AT is in the HOLD mode.
*3: The light stays illuminated for 6 seconds after the ignition switch has been turned ON if the driver’s seat belt is NOT fastened.
*4: The light illuminates when the AT is in the POWER mode.
*5: The light illuminates when the driver’s seat belt is NOT fastened.
*6: The light blinks when the ignition key has been removed from the ignition switch, or when 60 seconds or more time has passed
after the ignition key was inserted in the ignition switch and turned to the LOCK or ACC position.

IDI-5

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COMBINATION METER
Instrumentation/Driver Info

C: SPEEDOMETER
1. DESCRIPTION
D The speedometer system is an electrical type that uses electric signals from the speed sensor
in the MT model or the transmission control module (TCM) in the AT model.
D The vehicle speed sensor is installed on the manual transmission.
D Since the system does not use mechanical components such as rotating cable, there are no
opportunities of occurring such problems as meter needle vibration and cable disconnection.
Also, it does not constitute any means of mechanical noise transmission.
D The odometer and tripmeter readings appear on a liquid crystal display (LCD).

2. OPERATION
MT model: The vehicle speed sensor sends vehicle speed signals (4 pulses per rotation of speed
sensor’s driven shaft) to the speedometer drive circuit and odometer/tripmeter drive circuit in the
speedometer.
AT model: The TCM sends vehicle speed signals (4 pulses per rotation of output shaft) to the
speedometer drive circuit and odometer/tripmeter drive circuit in the speedometer.
NOTE:
Signals from the speed sensor or TCM are also used by the engine control module, automatic
transmission control module, etc.

3. SPECIFICATION

Speedometer Type Electric pulse type.

Indication Needle points to 60 km/h (37.3 miles) when 2,548 pulses are input per minute.
Odometer Type Pulse count type.
Display LCD/6 digits; 0 to 999,999 km (mile).
Counts up 1 km per 2,548 pulses (1 mile per 4,104 pulses). (Count down is impos-
Indication
sible.)
Tripmeter Type Pulse count type.
Display LCD/4 digits; 0 to 999.9 km and 1,000 to 9,999 km (mile).
Counts up 1 km per 2,548 pulses (1 mile per 4,104 pulses). (Push knob is adopted
Indication
to return the tripmeter to zero indication.)

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COMBINATION METER
Instrumentation/Driver Info

4. SYSTEM DIAGRAM

B6H1167B

(1) Odometer/tripmeter drive circuit (7) Front wheel

(2) Speedometer movement (8) Speed sensor
(3) Speedometer (9) TCM
(4) Odometer/tripmeter (10) Electromagnetic pick-up
(5) Speedometer drive circuit (11) Gear for the speed sensor
(6) Combination meter (12) Differential

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COMBINATION METER
Instrumentation/Driver Info

D: VEHICLE SPEED SENSOR

The vehicle speed sensor uses a Hall IC pick-up to generate speed signals. (MT model)
This sensor is installed on the transmission case and detects rotating speed of the transmission
output gear.
The sensor generates 4 pulses per rotation of the speed sensor driven shaft and send them to the
speedometer.

1. CONSTRUCTION
The speed sensor mainly consists of a Hall IC, magnet ring, driven shaft and spring.

B6H0911B

(1) Upper case (4) Driven key (7) Rivet

(2) O-ring (5) Lower case (8) Hall IC
(3) Magnet ring (6) Driven shaft

IDI-8

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COMBINATION METER
Instrumentation/Driver Info

2. OPERATION
As the driven key rotates, the magnet turns causing the magnetic field of the Hall IC to change.
The Hall IC generates a signal that corresponds to a change in the magnetic field.
One turn of the driven key in the speed sensor sends 4 pulses to the combination meter, engine
control module and cruise control module.

Signal (4 pulses
per revolution)

Revolution of Speedometer
transmission drive circuit
output gear
Vehicle speed
sensor Odometer and
tripmeter drive
circuit

B6H0912D

E: TACHOMETER
The tachometer drive circuit is connected to the engine speed sensing circuit in the engine control
module.
When the engine speed increases or decreases, the voltage of the circuit also increases or de-
creases, changing the magnetic force of the tachometer drive coil.
The tachometer needle then moves in accordance with change in the engine speed.

H6H0419

IDI-9

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COMBINATION METER
Instrumentation/Driver Info

F: WATER TEMPERATURE GAUGE

D The water temperature gauge is a cross-coil type.
D The water temperature signal is sent from the thermo gauge located on the engine.
D The resistance of the thermo gauge changes according to the engine coolant temperature.
Therefore, the current sent to the water temperature gauge also changes according to the engine
coolant temperature. As the change in current causes the magnetic force of the coil to change,
the gauge’s needle moves according to the engine coolant temperature.
D When the coolant is at a normal operating temperature of approx. 70 to 100 °C (158 to 212 °F),
the gauge’s needle stays in the middle of the indication range as shown below.

H6H0420

IDI-10

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COMBINATION METER
Instrumentation/Driver Info

G: FUEL GAUGE
1. GENERAL
D The fuel gauge unit consists of a float and a potentiometer whose resistance varies depending
on movement of the float. It is located inside the fuel tank and forms an integral part of the fuel
pump. The fuel gauge indicates the fuel level in the tank even when the ignition switch is in the
LOCK position.
D All models are equipped with two fuel level sensors. These sensors are installed in the fuel tank,
one on the right side and the other on the left side. Two sensors are necessary because the fuel
tank is divided into main and sub tank compartments.
D The low fuel warning light switch is incorporated in the main fuel level sensor.

NF0362

(1) Main fuel level sensor

(2) Sub fuel level sensor
(3) Float

IDI-11

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COMBINATION METER
Instrumentation/Driver Info

2. OPERATION
The low fuel warning light operates as follows:
The ECM continually monitors the resistance signal from the fuel level sensor. It turns on the low
fuel warning light in the combination meter if a resistance value corresponding to the critical fuel
level (approx. 80 Ω) is detected successively for about 10 minutes or the period spent for driving
a distance of 10 km.
This monitoring time has been decided to avoid false operation of the warning light which may
happen when a large part of remaining fuel is collected temporarily in the sub tank compartment.

B6H0026C

(1) Main fuel level sensor

(2) Sub fuel level sensor
(3) Fuel tank

3. SPECIFICATION
Fuel amount Resistance
Main fuel level FULL 0.5–2.5 Ω
sensor
1/2 20.7–24.7 Ω
EMPTY 50–52 Ω
Sub fuel level FULL 0.5–2.5 Ω
sensor
1/2 19.5–23.5 Ω
EMPTY 42–44 Ω

IDI-12

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COMBINATION METER
Instrumentation/Driver Info

4. CIRCUIT DIAGRAM

Sub tank Main tank

compartment compartment

B6H1281B

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OUTSIDE AIR TEMPERATURE DISPLAY

Instrumentation/Driver Info

2. Outside Air Temperature Display

A: CONSTRUCTION
The outside air temperature display system consists of an ambient sensor, the CUSTOM CPU and
a liquid crystal display installed in the combination meter. The ambient sensor detects the outside
air temperature using the built-in thermistor which varies its resistance according to change in am-
bient temperature, and sends signals to the CUSTOM CPU.
As soon as the ignition switch is turned ON, the CUSTOM CPU compares the temperature data
sent from the ambient sensor with the one that was stored in its memory when the ignition switch
was turned OFF last time and it causes the lower of the temperatures to be displayed. However,
if 60 minutes or more time has passed between the last turning OFF and the next turning ON of
the ignition switch, the temperature that is displayed is a sensor-provided temperature.
When the vehicle is running slowly, the heat released from the engine compartment raises the tem-
perature of the air around the ambient sensor and this affects the temperature data the sensor
sends to the CUSTOM CPU. The CPU then makes a special control using the vehicle speed data,
i.e., when the vehicle is running at a speed slower than 10 km/h, the CPU uses the temperature
that was detected during the most recent vehicle’s movement at a speed exceeding 10 km/h rather
than a temperature currently being provided by the ambient sensor.

S6H0425B

(1) Ambient sensor

(2) Outside air temperature display

IDI-14

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OUTSIDE AIR TEMPERATURE DISPLAY

Instrumentation/Driver Info

B: CIRCUIT DIAGRAM

B6H1515A

IDI-15

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OUTSIDE AIR TEMPERATURE DISPLAY

Instrumentation/Driver Info

MEMO

IDI-16

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SEATS SE
Page
1. Front Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Rear Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SE

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FRONT SEAT
Seats

1. Front Seat
A: ADJUSTMENT
D The height of each headrest is adjustable to any of the 4 positions available at 20 mm (0.79 in)
steps.
D The angle of each backrest is adjustable to any of the 29 positions available at 2° steps.
D The front seat can be slid back and forth to one of the 15 positions available at 13.5 mm (0.53
in) steps.

S5H0003B

SE-2

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FRONT SEAT
Seats

B: SEAT LIFTERS
D Rotating the front knob forward or backward causes the front lifter to lower or raise the front por-
tion of seat cushion.
D Rotating the rear knob forward or backward causes the rear lifter to lower or raise the rear portion
of seat cushion.

• Lowest position
of front portion

• Highest position
of front portion

• Lowest position
of rear portion

• Highest position
of rear portion

S5H0004B

SE-3

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FRONT SEAT
Seats

C: SEAT HEATER
The electric seat heater consists of wire heating elements embedded in the seat cushion and
backrest under the seat covering. Heating temperature can be selected between two settings:
high-temperature setting for quick warming and low-temperature setting for continuous warming.
Two thermostats are used to maintain a selected temperature and ensure safety.

G5H0503

SE-4

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REAR SEAT
Seats

2. Rear Seat
D A head restraint is provided for each of the three seating places.
D The backrest is split into two portions at a 6-to-4 width ratio. Each portion is foldable indepen-
dently.

S5H0415

SE-5

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REAR SEAT
Seats

MEMO

SE-6

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SECURITY AND LOCKS SL

Page
1. Ignition Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Power Door Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Keyless Entry System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Immobiliser System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

SL

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IGNITION SWITCH
Security and Locks

1. Ignition Switch
A: DESCRIPTION
When turning the ignition key from “ACC” to “LOCK”, it is necessary to push the key at the “ACC”
position (arrow 1 in the illustration) and then turn it to the “LOCK” position (arrow 2).

S6H0146B

(1) Ignition switch

(2) Ignition key cylinder

SL-2

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POWER DOOR LOCK

Security and Locks

2. Power Door Lock

A: CONSTRUCTION
D The power door lock system consists of a keyless entry control module, a driver’s door lock
switch, a front passenger’s door lock actuator, rear door lock actuators, and a rear gate lock actua-
tor.
D When the driver locks or unlocks the driver’s door using the inside lock knob, the other doors
and the rear gate are also locked or unlocked automatically.

B: CIRCUIT DIAGRAM
Refer to the “Keyless Entry System” section on the next page.

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KEYLESS ENTRY SYSTEM

Security and Locks

3. Keyless Entry System

A: CONSTRUCTION
D The keyless entry system consists of a transmitter, keyless entry control module (with a built-in
antenna), door lock actuators, door switches, hazard warning lights and interior light.
D The keyless entry system operates on a radio frequency, so its transmitter can be used in almost
all directions relative to the vehicle.

B: FUNCTION
1. DOOR LOCKING
1) Push the transmitter’s LOCK button once.
2) All doors are locked.
3) Check that the hazard warning lights flash once.

2. DOOR UNLOCKING (DRIVER’S DOOR)

1) Push the transmitter’s UNLOCK button once.
2) The driver’s door is unlocked, the ignition switch illumination light turns ON and the interior light
turns ON (when the interior light switch is set at the DOOR position).
NOTE:
The interior light and ignition switch illumination light illuminate for 30 seconds and then go out.
(However, if the ignition switch is turned ON or a door locking procedure is performed again during
this period, the light will go out immediately.)
3) Check that the hazard warning lights flash twice.

3. DOOR UNLOCKING (ALL DOORS)

1) Push the transmitter’s UNLOCK button twice.
2) All doors are unlocked.
3) No audible or visible sign is given even after all the doors are unlocked.

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KEYLESS ENTRY SYSTEM

Security and Locks

C: CIRCUIT DIAGRAM

S6H0557A

(1) Keyless entry control module (10) Ignition switch illumination light (19) Door lock switch
(2) Battery (11) Turn signal output (RH) (20) Driver door lock actuator
(3) Antenna (12) Turn signal output (LH) (21) Passenger door lock actuator
(4) Key switch (13) Meter indicator light (22) Rear door lock actuator (RH)
(5) Door switch (14) Side turn signal light (23) Rear door lock actuator (LH)
(6) Rear gate switch (15) Front turn signal light (24) Rear gate lock actuator
(7) Storage switch (connector) (16) Rear turn signal light (25) Ground
(8) CPU (17) Door lock output
(9) Interior light (18) Door unlock output

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IMMOBILISER SYSTEM
Immobiliser System

4. Immobiliser System
A: CONSTRUCTION
The immobiliser system consists of the following components: an indicator light in the combination
meter, an immobiliser control module (IMM ECM), an engine control module (ECM), a transponder
inside the ignition key, and an antenna fitted to the key cylinder.
The antenna receives a vehicle ID code emitted from the transponder when the key is inserted into
the key cylinder.
The ID code is transmitted to the IMM ECM. The IMM ECM compares the code with a one that has
been registered in it. If these ID codes match with each other, the system allows the engine to be
started. If they do not match but the key fits in, turning the key may be able to start the engine. The
engine, however, will automatically stop after a few seconds.
The immobiliser function is activated automatically when the key is removed from the key cylinder
and when 60 seconds have passed after the ignition switch was turned to the “ACC” or “OFF” posi-
tion. When the function is activated, the indicator light flashes at intervals of 0.2-second ON and
2.8-second OFF.
This indicator light flashing indicated that the system is ready to function if an action of theft is at-
tempted.
In the event that the immobiliser system develops a fault, the CHECK ENGINE warning light flashes
when the ignition switch is turned to the “ON” position.

B6H0586B

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IMMOBILISER SYSTEM
Immobiliser System

B: TEACHING OPERATION
The teaching operation is a procedure that must be carried out when an additional key is pur-
chased, the IMM ECM is replaced, or the keys are replaced. The procedure includes initialization
of the system and re-registration of the ID code. Once initialized, the system loses the ID code it
has retained so far and has no code until a new code is registered. An ID code can be registered
with an IMM ECM for up to four keys (transponders).
Any set of keys (four maximum) can be registered only with one IMM ECM. So, if an IMM ECM is
replaced with a new one, the keys having been used with the old IMM ECM cannot be used with
the new IMM ECM. Therefore, the keys must be replaced simultaneously with the IMM ECM.
The teaching operation is carried out using a select monitor and a special program by an autho-
rized person. Access to the program is strictly controlled for reasons of security.

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IMMOBILISER SYSTEM
Immobiliser System

MEMO

SL-8

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SUNROOF/T-TOP/
CONVERTIBLE TOP SR
Page
1. Sunroof ................................................................................2

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SUNROOF
Sunroof/T-top/Convertible Top

1. Sunroof
A: DESCRIPTION
D The sunroof is a sliding glass type. The sunroof opening in the roof is 695 mm (27.36 in) in length
and 710 mm (27.95 in) in width.
D The sunroof consists of a 4.7 mm (0.19 in) thick glass lid, deflector and sunshade.

B: FUNCTION

S5H0284B

(1) Deflector
(2) Glass lid
(3) Sunshade

1. OPEN AND CLOSE OPERATIONS

D The glass lid opens when the sunroof switch is pressed in the opening direction. If the switch
is kept pressed, the glass lid continues to open until it reaches a point 500 mm (19.69 in) away
from the front edge of the sunroof opening. The glass lid goes to the fully open position if the sun-
roof switch is pressed again.
D The glass lid closes when the sunroof switch is pressed in the closing direction. If the switch is
kept pressed, the glass lid continues to close until it reaches a point 150 mm (5.91 in) away from
the front edge of the sunroof opening. The glass lid goes to the fully closed position if the sunroof
switch is pressed again.
2. DEFLECTOR OPERATION
The deflector moves up or down in synchronization with opening or closing operation of the glass
lid.
3. SUNSHADE OPERATION
The sunshade automatically opens when the glass lid opens. When the glass lid is fully closed,
the sunshade can be opened or closed manually.

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EXTERIOR/INTERIOR TRIM EI
Page
1. Instrument Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

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INSTRUMENT PANEL
Exterior/Interior Trim

1. Instrument Panel
D The following items are provided in the instrument panel.
D Center storage box
D Cup holder
D Glove compartment
D Pocket
D Barrel type vent grills
D There is a support beam connecting the left and right pillars behind the instrument panel. The
instrument panel is mounted on the support beam.
D A data link connector access hole is provided.
D Design of center panel has been changed by adoption of Japanese 1 DIN size audio system.

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INSTRUMENT PANEL
Exterior/Interior Trim

A: EUROPE MODEL

S5H0499A
(1) Barrel type vent grill (4) Pocket (7) Steering support beam
(2) Center storage box (5) Data link connector access hole
(3) Cup holder (6) Passenger airbag module

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INSTRUMENT PANEL
Exterior/Interior Trim

B: EXCEPT EUROPE MODEL

S5H0286B

(1) Barrel type vent grill (4) Pocket (7) Steering support beam
(2) Center storage box (5) Data link connector access hole
(3) Cup holder (6) Passenger airbag module

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EXTERIOR BODY PANELS EB

Page
1. Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

EB

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DOOR
Exterior Body Panels

1. Door
A: DOOR CHECKER
The door checkers are of a new type that uses a molded resin part.

S5H0001A

B: DOOR CONSTRUCTION
D All the front and rear doors have in their inside side door beams, inner reinforcements and rein-
forcement latches.
D An additional reinforcement has been provided for each rear door upper reinforcement.
D A lower reinforcement has been added to each rear door.

S5H0498A

(1) Inner reinforcement (4) Outer upper reinforcement

(2) Reinforcement latch (5) Lower reinforcement
(3) Side door beam

EB-2

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CRUISE CONTROL SYSTEM CC

Page
1. Cruise Control ........................................................................2

CC

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CRUISE CONTROL
Cruise Control System

1. Cruise Control
A: OPERATION
D The cruise control system automatically controls the vehicle speed. It allows the vehicle to run
at a constant speed without need for the driver to keep the accelerator pedal depressed.
D When the driver has activated the system and made a desired speed setting, the cruise control
module compares the actual vehicle speed detected by the speed sensor (MT) or transmission
control module (AT) with the preset speed in the memory, then generates a signal according to
the difference between the two speeds.
This signal is transmitted to the actuator located in the engine compartment.
The actuator operates the throttle cam as necessary to keep the preset vehicle speed.

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CRUISE CONTROL
Cruise Control System

B: COMPONENT LOCATION
1. ENGINE COMPARTMENT
TURBO ENGINE MODEL:

S6H0550A

(1) Actuator
(2) Inhibitor switch (AT)

NON-TURBO ENGINE MODEL:

S6H0551A

(1) Actuator (with valves)

(2) Inhibitor switch (AT)

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CRUISE CONTROL
Cruise Control System

2. PASSENGER COMPARTMENT

S6H0552A

(1) Command switch (cruise control lever)

(2) Main switch
(3) Clutch switch (MT)
(4) Stop and brake switch
(5) Cruise control module

The electrical component locations are for LHD vehicles. The cruise control actuator and the
cruise control module locations for RHD vehicles are symmetrically opposite.

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CRUISE CONTROL
Cruise Control System

C: CONTROL AND OPERATION

1. TURBO ENGINE MODEL
When actual vehicle speed is higher than the “set” speed, the motor in the actuator operates to move the
Constant speed throttle valve in the closing direction by the amount corresponding to the difference between the two speeds.
control When actual driving speed is lower than “set” speed, the motor operates to move the throttle valve in the
opening enabling direction according to the difference in speed.
When SET/COAST switch is pressed with main switch ON while the vehicle is being driven at a speed great-
Speed setting er than 40 km/h (25 MPH), current flows to the actuator. This causes the clutch in the actuator to engage,
control enabling the motor to operate. The motor moves the throttle valve to the position corresponding to the accel-
erator pedal position. The vehicle is driven at the set speed.
When SET/COAST switch is turned ON while the vehicle is cruising at a constant speed, the motor in the
Deceleration actuator rotates to move the throttle valve in the closing direction. This causes the vehicle to decelerate by a
control certain amount. When the switch is turned OFF, the vehicle speed is stored in memory and the vehicle main-
tains that speed thereafter.
When RESUME/ACCEL switch is turned ON while the vehicle is cruising at a constant speed, the motor in
Acceleration the actuator rotates to move the throttle valve in the opening direction. This causes the vehicle to accelerate
control by a certain amount. When the switch is turned OFF, the vehicle speed is stored in memory and the vehicle
maintains that speed thereafter.
When RESUME/ACCEL switch is turned ON after the cruise control is temporarily cancelled, vehicle speed
returns to that speed which was stored in memory just before the cruise control is cancelled. This occurs only
when the vehicle is running at a speed greater than 32 km/h (20 MPH).
Resume control In the following cases, however, the set vehicle speed is completely cleared. Therefore, no resume control is
performed.
(1) Ignition switch is turned OFF
(2) Main switch is turned OFF
When any of the following signals is entered into the clutch control module, the clutch is disengaged and the
cruise control is deactivated.
Manual cancel (1) Stop light switch ON signal (Brake pedal depressed) (2) Brake switch OFF signal (Brake pedal de-
control pressed) (3) Clutch switch OFF signal (Clutch pedal depressed – MT) (4) Inhibitor switch ON signal (Selector
lever set to “N” – AT) (5) CANCEL switch ON signal (Command switch cruise control lever pulled) (6) Ignition
switch OFF signal (7) Main switch OFF signal
Low speed limit When the vehicle speed drops below 32 km/h (20 MPH), the cruise control is automatically cancelled. Cruise
control control at any speed lower than 40 km/h (25 MPH) cannot be effected.
When the vehicle speed becomes 10 km/h (6 MPH) or more higher than the memorized speed while vehicle
is running utilizing the cruise control (in a downgrade, for example), the actuator’s clutch is turned OFF so
Motor control
that the vehicle decelerates. When the vehicle’s speed decreases by more than 8 km/h (5 MPH) from the
memorized speed, the clutch is turned ON again so that the cruise control resumes.

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CRUISE CONTROL
Cruise Control System

2. NON-TURBO ENGINE MODEL

When actual vehicle speed is higher than the “set” speed, cruise control system intermittently opens vent
Constant speed valve and moves the throttle valve in the closing direction. This occurs while comparing the actual driving
control speed with the “set” speed. When the actual the driving speed is lower than the “set” speed, the system inter-
mittently operates the vacuum valve and moves the throttle valve in the opening direction.
When SET/COAST switch is pressed with the main switch ON while vehicle is being driven at a speed great-
Speed setting er than 40 km/h (25 MPH), current flows so that the vent and safety valves close. This causes the vacuum
control valve to intermittently activate to the set the throttle valve at a position that corresponds to the accelerator
pedal position. Thus, the vehicle is driven at the set speed.
When SET/COAST switch is turned ON while the vehicle is cruising, the vent valve intermittently opens, par-
Deceleration
tially closing the throttle valve. This causes the vehicle to decelerate. When the switch is turned OFF, the
control
vehicle speed is stored in memory and the vehicle maintains that speed thereafter.
When RESUME/ACCEL switch is turned ON while the vehicle is cruising, the vacuum valve intermittently
Acceleration
activates to partially open the throttle valve. This causes the vehicle to accelerate. When the switch is turned
control
OFF, the vehicle speed is stored in memory and the vehicle maintains that speed thereafter.
When RESUME/ACCEL switch is turned ON after the cruise control is temporarily cancelled, vehicle speed
returns to that speed which was stored in memory just before the cruise control is cancelled. This occurs only
when the vehicle is running at a speed greater than 35 km/h (22 MPH).
Resume control
In the following cases, however, the set vehicle speed is cleared. Therefore, no resume control is performed.
(1) Ignition switch is turned OFF
(2) Main switch is turned OFF
When any of the following signals is entered, the vent valve and safety valve open to deactivate the cruise
Manual cancel control.
control (1) Brake pedal depressed (2) Clutch pedal depressed (MT) (3) Selector lever set to “N” or “P” (AT)
(4) CANCEL switch ON signal (5) Ignition switch OFF signal (6) Main switch OFF signal
Low speed limit When the vehicle speed drops below 35 km/h (22 MPH), the cruise control is automatically cancelled. Cruise
control control at speed lower than 40 km/h (25 MPH) cannot be effected.
When the vehicle speed becomes 10 km/h (6 MPH) higher than the memorized speed while the vehicle is
running using the cruise control (in a downgrade, for example) the actuator’s vent valve as well as safety
Release valve
valve turns OFF (to open to the atmospheric pressure) so that vehicle decelerates. When the vehicle’s speed
control
decreases by more than 7 km/h (4.3 MPH) from the memorized speed, the vent and safety valves are turned
ON (to shut out the atmospheric pressure) so that the cruise control resumes.

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CRUISE CONTROL
Cruise Control System

D: SCHEMATIC
1. TURBO ENGINE MODEL

NF0258

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CRUISE CONTROL
Cruise Control System

2. NON-TURBO ENGINE MODEL

S6H0318C

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CRUISE CONTROL
Cruise Control System

E: CIRCUIT DIAGRAM
1. TURBO ENGINE MODEL

NF0259

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CRUISE CONTROL
Cruise Control System

2. NON-TURBO ENGINE MODEL

S6H0554A

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CRUISE CONTROL
Cruise Control System

F: SYSTEM CONSTRUCTION
1. TURBO ENGINE MODEL

Vehicle
Unit Name Function Set Cancel Resume Coast
speed
Input Supplies battery voltage to control
signal Main switch module after main switch is turned f f f f f
(sensors) ON (with ignition switch ON).
SET/
Sends a SET/COAST signal to
COAST f f
control module.
switch
RESUME/
Sends a RESUME/ACCEL signal
ACCEL f
to control module.
switch
Simultaneously sends SET/
CANCEL
COAST and RESUME/ACCEL f
switch
signals to control module.
Brake Disconnects power supply to
f f
switch (NC) clutch and stepping motor.
Stop light Sends a cancel signal to control
f f
switch (NO) module.
Clutch
switch (NC) Sends a cancel signal to control
f f
or inhibitor module.
switch (NO)
Vehicle
speed Detects vehicle speed. f f f f f
sensor
Control A safety device to protect system
Built-in relay f f f f f
section from damage.
Output Stepping
signal motor Controls vehicle speed. f f f
(PULL)
Stepping
motor Controls vehicle speed. f f f
(RELEASE)
Clutch Cancels cruise control setting f f f f f

NC:Normally closed
NO:Normally open

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CRUISE CONTROL
Cruise Control System

2. NON-TURBO ENGINE MODEL

Vehicle
Unit Name Function Set Cancel Resume Coast
speed
Input Supplies battery voltage to control
signal Main switch module after main switch is turned f f f f f
(sensors) ON (with ignition switch ON).
SET/
Sends a SET/COAST signal to
COAST f f
control module.
switch
RESUME/
Sends a RESUME/ACCEL signal
ACCEL f
to control module.
switch
Simultaneously sends SET/
CANCEL
COAST and RESUME/ACCEL f
switch
signals to control module.
Brake Disconnects power supply to
f f
switch (NC) control valve.
Stop light Sends a cancel signal to control
f f
switch (NO) module.
Clutch
switch (NC) Sends a cancel signal to control
f f
or inhibitor module.
switch (NO)
Set signal f
Vehicle
speed Detects vehicle speed. f f f f f
sensor
Control A safety device to protect system
Built-in relay f f f f f
section from damage.
Output Activates when controlling vehicle
Vacuum
signal speed supplies vacuum pressure f f f f
valve
to actuator.
Activates when controlling vehicle
Vent valve speed. (Vacuum pressure → f f f f f
Atmospheric pressure)
Opens to introduce atmospheric
Safety valve pressure into system if vent valve f f f f f
malfunctions.

NC:Normally closed
NO:Normally open

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Cruise Control System

G: ACTUATOR (TURBO ENGINE MODEL)

In response to a signal from the cruise control module, the clutch in the actuator is turned ON. This
causes the stepping motor to operate, pulling the throttle cam for speed control.

B6H1309A

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Cruise Control System

H: ACTUATOR (NON-TURBO ENGINE MODEL)

The actuator has a diaphragm whose movement is controlled using vacuum and atmospheric
pressure. The vacuum is controlled by the vacuum valve and the atmospheric pressure is con-
trolled by the vent valve. The diaphragm is connected to the throttle valve through the cruise con-
trol cable and linkage so that the throttle valve opens to closes as the diaphragm moves. With the
cruise control turned OFF (system deactivated), no diaphragm operation occurs as the atmo-
spheric pressure is prevailing inside the actuator.

Control system Vacuum pressure operation

Diaphragm stroke 35 mm (1.38 in)
Rated voltage 12 V
Effective diameter of diaphragm 150 mm (5.91 in)
Effective area of diaphragm 125 cm2 (19.4 sq in)

: Vacuum chamber
S6H0021C

(1) Vacuum valve (6) Engine vacuum

(2) Filter (7) Cable
(3) Vent valve (8) Vacuum
(4) Safety valve (9) Atmosphere
(5) To control module (10) Diaphragm

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Cruise Control System

1. VALVE OPERATIONS
D When the cruise control is out of operation, the safety valve and vent valve are open, while the
vacuum valve is closed. In this condition, the inside of the actuator is exposed only to the atmo-
spheric pressure, so that the diaphragm does not move.
During constant-speed driving with the main switch on, the safety valve closes and the vacuum
valve and vent valve individually open and close to adjust the vacuum in the actuator. According
to the vacuum thus adjusted, the diaphragm moves to a certain position, enabling the throttle cam
linked with it to keep the corresponding vehicle speed.
D The vacuum valve opens to introduce vacuum when it is energized and closes when it is not
energized.
D The vent valve closes when it is energized to shut off atmospheric pressure and retain the vacu-
um in the vacuum chamber. When the vent valve is not energized, it opens, allowing the chamber
to be exposed to the atmospheric pressure.
D The safety valve closes when it is not energized to block the atmospheric pressure from acting
on the vacuum chamber. It opens when it is energized.
When cruise control is cancelled or when the vehicle is decelerated, the vent valve also opens to
quicken deceleration by opening the vacuum chamber to the atmospheric pressure.

Vacuum chamber S6H0022B

How the valves operate in response to signals from the control module:
( ) : Operation mode Vacuum valve Vent valve Safety valve
System OFF ( ——— ) Close Open Open
System ON Set speed < Actual speed (RELEASE) Close Open Close
Set speed = Actual speed (HOLD) Close Close Close
Set speed > Actual speed (PULL) Open Close Close
(CANCEL) Close Open Open

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Cruise Control System

I: MAIN SWITCH
D The main switch is the main power supply switch of the cruise control module. It has a built-in
power indicator and night illumination light.
D When the ignition switch is placed in the OFF position with the main switch ON, the main switch
is also turned OFF. Even if the ignition switch is turned ON again, the main switch will stay in the
OFF state.

B6H1173B

J: COMMAND SWITCH (CRUISE CONTROL LEVER)

D When the vehicle is driven with the cruise control activated, the command switch controls its
operation. It inputs SET/COAST signal, ACCEL/RESUME signal or CANCEL signal to the cruise
control module.

B6H1310A

D The command switch is located on the right side of the steering wheel, so the driver can operate
it without releasing hands from the steering wheel.
D The command switch is a self-returning lever type.

1. RESUME/ACCEL AND SET/COAST SWITCH

Each switch contact is held closed as long as the lever is kept pressed in the relevant direction
and resulting current is applied as a signal to the control module.
2. CANCEL SWITCH
All the switch contacts are closed as long as the lever is pulled toward the CANCEL position (to-
ward the driver). This causes the RESUME/ACCEL and SET/COAST ON signals to be sent to the
control module simultaneously.

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Cruise Control System

K: CANCEL SIGNALS
The cancel signal deactivates the cruise control function. Operating any of the following switches
results in generation of the cancel signal. On receiving the signal, the cruise control module can-
cels the cruise control function.
D Stop light switch
D Brake switch
D Clutch switch (MT model)
D Inhibitor switch (AT model)
D Main switch
D Command switch (CANCEL position)

L: VEHICLE SPEED SENSOR

Vehicle speed sensor is installed on the transmission, and sends signal to the cruise control mod-
ule which uses it in controlling the cruise control function (MT model).

M: ENGINE THROTTLE
D The throttle body is equipped with two throttle cams. One is used during acceleration and the
other during cruising in order to open or close the throttle valve.
D These cams operate independently of each other. In other words, when one cam operates, the
other may not.

B6H1300A

(1) Accelerator cable

(2) Cruise control cable
(3) Throttle cam

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Cruise Control System

N: CONTROL MODULE
D Based on signals from the related switches and sensors, the cruise control module controls all
the following control functions:
Constant speed control; speed setting control; deceleration control; acceleration control; resume
control; manual cancel control; low speed limit control; stepping motor control (turbo engine mod-
el); clutch control (turbo engine model); release valve control (non-turbo engine model)
D The control module (A) is located inside of the front pillar lower portion (passenger side).

S6H0019C

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O: FAIL-SAFE FUNCTION (TURBO ENGINE MODEL)

The cruise control system has a fail-safe function that cancels the cruise control operation when
any of the following conditions occurs.

1. CONFLICT BETWEEN CRUISE CONTROL SWITCHES AND CANCELLATION SIGNAL

GENERATING SWITCHES
1) The cruise control system is deactivated if any of the cruise control switches (SET/COAST, RE-
SUME/ACCEL, and CANCEL switches) is turned ON while any of the cancellation signal generat-
ing switches (brake, stop lamp, clutch, and inhibitor switches) is being operated. The system is
re-activated when the cruise control switch is turned OFF and then turn ON again after the can-
cellation signal generating switch has been returned to its released position.
2) The cruise control system becomes deactivated if the main switch is turned ON with any of the
cruise control switches in the ON position. The system deactivating function is retained until the
main switch is turned OFF.

2. ABNORMALITIES IN ELECTRIC CIRCUITS

The cruise control system is deactivated and the set speed is also canceled if any of the following
abnormalities occurs in the system’s electric circuits.
The system deactivation function is retained until the ignition switch or the main switch is turned
OFF.
1) The stepping motor terminal is grounded or disconnected; or the stepping motor drive circuit
is broken due to a short-circuit.
2) The stepping motor clutch drive circuit is shorted.
3) Vehicle speed variation in a 350 ms period exceeds ±10km/h.
4) Fusion has occurred in an internal relay and is detected while the vehicle is running with the
cruise control deactivated.
5) The cruise control module becomes inoperative or its operation is faulty.
6) There is discrepancy between the values stored in the two RAMs of the control module.
7) An abnormality is detected as a result of the self-diagnosis performed after turning ON of the
ignition switch.

3. ABNORMALITIES IN STEPPING MOTOR

The cruise control system is deactivated if either of the following abnormalities occurs in the step-
ping motor.
1) The stepping motor does not operate properly.
2) The stepping motor is energized for unduly long period and too frequently.
When the system is deactivated by any of these causes, it cannot be reactivated for 2 – 20 minutes
after detection of the abnormal condition.

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 W8050GE 01 MY FORESTER New Car Features 73J欧州 Gr. CC01

CRUISE CONTROL
Cruise Control System

P: FAIL-SAFE FUNCTION (NON-TURBO ENGINE MODEL)

In addition to the normal and automatic cancelling functions as described in paragraphs 1 and
2 below, the cruise control system has a fail-safe cancelling function as described in paragraph
3.

1. NORMAL CANCELLING FUNCTION

D If any of the following action is performed, the system is cancelled.
1) Brake pedal is depressed.
2) Clutch pedal is depressed. (MT model)
3) Selector lever is placed in the “P” or “N” position. (AT model)
4) Cruise control main switch is turned off.

2. AUTOMATIC CANCELLING FUNCTION

D If any of the following states occurs, the system is automatically cancelled.
1) Vehicle speed lowers below the minimum system operation speed.
2) Vehicle speed lowers 15 ± 3 km/h than the set speed.

3. FAIL-SAFE CANCELLING FUNCTION

D If any of the following states occurs, the system is cancelled.
1) Faults in cruise control module
(1) The condition of the actuator drive circuit does not coincide with the output condition of
CPU.
(2) Fault occurs in the command switch input circuit.
(3) Set speed (CPU RAM value) is abnormal.
(4) Fault occurs in the cancel latch circuit.
2) Abnormality in vehicle speed inputs
D If the following state occurs, the system is temporarily cancelled.
(1) Vehicle speed becomes 10 km/h higher than the set speed.
In this case, the system resumes operation when the vehicle speed becomes lower than the
set speed + 7 km/h.

CC-20

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