1997 SUBARU LEGACY air condition

BRAKES
[M13-5]
4-413
.
Anti-lock
Brake
System
(AB
S)
[
5
.3i
Typ
e]

"
HYDRAULIC
CONTROL
UNIT
SECTION
(H/U)

The
H/U
is
a
fluid
pressure
controller
comprising
a
motor,
solenoid
valve,
housing,
relay,
etc
.
It

constitutes
two
diagonally
independent
brake
fluid
circuits
for
a
cross
piping
vehicle
.

"
The
pump
motor
rotates
an
eccentric
cam
to
let
the
plunger
pump
generatea
hydraulicpres-

sure
.

"
The
housing
accommodates
the
pump
motor,
solenoid
valve,
reservoir,
etc
.,
and
also
consti-
tutes
abrake
fluid
passage
.

"
The
plunger
pump
is
a
hydraulic
pump
which
drains
off
the
brake
fluid
which,
when
the
pressure

is
reduced,
is
discharged
to
the
reservoir,
and
sends
it
toward
the
master
cylinder
.

"
The
solenoid
valve
is
a
2-position
type
solenoidvalve
which
switches
the
brake
fluid
passages

between
the
wheel
and
master
cylinder
and
reservoir
sides
in
response
to
an
instruction
from
the

ABSCM
.

For
each
wheel
cylinder,
a
pairof
normally-closed
and
-opened
solenoid
valves
are
provided
.

*
The
inlet
solenoid
valve
is
duty-controlled
to
reduce
brake
fluid
pulsation
for
IowerABS
operation

noise
.

"
The
reservoir
is
a
fluid
chamber
which
temporarily
storesthe
brake
fluid
to
be
discharged
from

the
wheel
cylinder
when
the
pressure
is
reduced
.

"
The
damper
chamber
suppresses
thepulsation
of
the
brake
fluid
which,
when
the
pressure
is

reduced,
is
discharged
from
the
plunger
pump,
thereby
minimizing
the
kickbacks
to
the
brake

pedal
.

*
The
valve
relay
controls
the
solenoid
valve
and
motor
relay
energizing
power
supply
in
response

to
an
instruction
from
the
ABSCM
.
In
normal
(1G
ON)
condition,
the
relay
is
actuated
to
supply

power
to
the
solenoid
valve
and
motor
relay
.
When
an
error
occurs
in
the
system,
the
valve
relay

is
forced
to
OFF
to
keep
the
fluid
pressure
circuit
in
the
normal
mode
(normal
brake
mode)
and

also
constitute
the
ABS
warning
light
operating
circuit
.

"
The
motor
relay
supplies
power
to
the
pump
motor
to
operate
the
plunger
pump
in
response
to

an
instruction
from
the
ABSCM
in
the
ABS
control
mode
.

TheH/U
has
four
operating
modes
;
normal
mode
(control
OFF
:
normalbrake
mode),
"increase",

"hold"
and
"decrease"
modes
(control
ON
in
all
the
three
modes)
.

7

4-4
[w2sBO]
SERVICE
PROCEDURE

25
.
ABS
Control
Module
and
Hydraulic
Control
Unit
(ABSCM&H/U)
[ABS
5
.3i
Type]

B
:
INSPECTION

i
Mark

>
ABSCM&H/U
B4M
1248A

/Pressure
ga
u
ge
\
'
/\

B4M0633A

1)
Check
connected
and
fixed
condition
of
connector
.

2)
Check
specifications
of
the
mark
with
ABSCM&H/U
.

Mark
Model

C3
AWD
AT

C4
AWD
MT

C
:
CHECKING
THE
HYDRAULIC
UNIT
ABS

OPERATION

1
.
CHECKINGTHE
HYDRAULIC
UNIT
ABS
OPERATION

BY
PRESSURE
GAUGE

1)
Lift-up
vehicle
and
remove
wheels
.

2)
Disconnect
the
air
bleeder
screwsfrom
the
FL
andFR

caliper
bodies
.

3)
Connect
two
pressure
gauges
to
the
FL
andFR
cali-

perbodies
.

CAUTION
:

Pressure
gauges
used
exclusively
for
brake
fluid

must
be
used
.

e
Do
not
employ
pressure
gauge
previously
used
for

transmission
since
the
piston
seal
is
expanded
which

may
lead
to
malfunction
of
the
brake
.

NOTE
:

Wrap
sealing
tape
around
the
pressure
gauge
.

8

4-4d
[T1oo]
BRAKES
[ABS
5
.31
TYPE]

1
.
Supplemental
Restraint
System
"Airbag"
-
2
.
Pre-inspection

1
.
Supplemental
Restraint
System

"Airbag"

Airbagsystem
wiring
harness
is
routed
near
the
ABS

sensor,
ABS
control
module
and
hydraulic
control
unit
.

CAUTION
:

All
Airbag
system
wiring
harness
and
connectors
are

colored
yellow
.
Do
not
use
electrical
test
equipment
on

these
circuit
.

e
Be
careful
not
to
damage
Airbag
system
wiring
har-

ness
when
servicing
the
ABS
sensor,
ABS
control
mod-

ule
and
hydraulic
control
unit
.

2
.
Pre-inspection
Before
performing
diagnostics,
check
the
following
items

which
might
affect
ABS
problems
:

A
:
MECHANICAL
INSPECTION

1
.
POWER
SUPPLY

1)
Measure
battery
voltage
and
specific
gravity
of
electro-

lyte
.

Standard
voltage
:
12
V,
or
more

Specific
gravity
:
Above
1
.260

2)
Check
the
condition
of
the
main
and
other
fuses,
and

harnesses
and
connectors
.
Also
check
for
proper
ground-

ing
.

2
.
BRAKE
FLUID

1)
Check
brake
fluidlevel
.

2)
Check
brake
fluid
leakage
.

3
.
BRAKEDRAG

Check
brake
drag
.
<
Ref
.
to
4-4
[K100].*1
>

4
.
BRAKE
PADAND
ROTOR

Check
brake
padand
rotor
.
<
Ref
.
to
4-4
[K100].*1
>

5
.
TIRE
SPECIFICATIONS,
TIRE
WEARAND
AIR

PRESSURE

Check
tire
specifications,
tire
wear
and
air
pressure
.
<
Ref
.

to
4-2
[S1
A1
],
[S1
A2]
.*1
>

2

4-4d
[T1oo]
BRAKES
[ABS
5
.31
TYPE]

1
.
Supplemental
Restraint
System
"Airbag"
-
2
.
Pre-inspection

1
.
Supplemental
Restraint
System

"Airbag"

Airbagsystem
wiring
harness
is
routed
near
the
ABS

sensor,
ABS
control
module
and
hydraulic
control
unit
.

CAUTION
:

All
Airbag
system
wiring
harness
and
connectors
are

colored
yellow
.
Do
not
use
electrical
test
equipment
on

these
circuit
.

e
Be
careful
not
to
damage
Airbag
system
wiring
har-

ness
when
servicing
the
ABS
sensor,
ABS
control
mod-

ule
and
hydraulic
control
unit
.

2
.
Pre-inspection
Before
performing
diagnostics,
check
the
following
items

which
might
affect
ABS
problems
:

A
:
MECHANICAL
INSPECTION

1
.
POWER
SUPPLY

1)
Measure
battery
voltage
and
specific
gravity
of
electro-

lyte
.

Standard
voltage
:
12
V,
or
more

Specific
gravity
:
Above
1
.260

2)
Check
the
condition
of
the
main
and
other
fuses,
and

harnesses
and
connectors
.
Also
check
for
proper
ground-

ing
.

2
.
BRAKE
FLUID

1)
Check
brake
fluidlevel
.

2)
Check
brake
fluid
leakage
.

3
.
BRAKEDRAG

Check
brake
drag
.
<
Ref
.
to
4-4
[K100].*1
>

4
.
BRAKE
PADAND
ROTOR

Check
brake
padand
rotor
.
<
Ref
.
to
4-4
[K100].*1
>

5
.
TIRE
SPECIFICATIONS,
TIRE
WEARAND
AIR

PRESSURE

Check
tire
specifications,
tire
wear
and
air
pressure
.
<
Ref
.

to
4-2
[S1
A1
],
[S1
A2]
.*1
>

2

4-4d
[TSao]
BRAKES
[ABS
5
.3i
TYPE]

6
.
Diagnostics
Chart
for
On-board
Diagnosis
System

Condition
a)
Brakes
Deceleration
:
g

O
Continuous
/
Olntermittent

b)
AcceleratorAcceleration
:
g

O
Continuous
/
O
Intermittent

c)
Vehicle
speed
km/h
MPH

O
Advancing

O
Accelerating

O
Reducing
speed

O
Low
speed

O
Turning

D
Others

d)
Tire
inflation
pressure
Front
RH
tire
:
kPa

Front
LH
tire
:
kPa

Rear
RH
tire
:
kPa

Rear
LH
tire
:
kPa

e)
Degree
of
wear
Front
RH
tire

Front
LH
tire

Rear
RH
tire

Rear
LH
tire

f)
Genuine
parts
are
used
.:
Yes
/
ONo

g)
Chain
is
passed
around
tires
.:
Yes
/
DNo

h)
T
tire
is
used
.:
Yes
/
ONo

i)
Condition
of
suspension
alignment

j)
Loading
state

k)
Repair
parts
are
used
.
:
OYes
/
ONo

What

I)
Others

14

4-4d[T9B0]
BRAKES
[ABS
5
.31
TYPE]

9
.
Select
Monitor
Function
Mode

1997
(F00)

AB
S
4WD
"
AT

H4M1117

B
:
MODE
F00

-
ROM
ID
NUMBER
(ROM)
-

CONDITION
:

Ignition
switch
ON

SPECIFIED
DATA
:

Presentation
display

911311
CHECK
MESSAGE
OF
DISPLAY
.

CHECK
;
Does
display
indicate
message
"Error
I"?

Repair
loose
or
disconnect
connector,
or
discon-

tinued
circuit
in
data
linkcircuit
.

No
:
Go
to
step
982
.

FR
(F05)

30
km/h

B4M0922

191132
I
CHECK
MESSAGE
OF
DISPLAY
.

CHECK
:
Does
display
indicate
message
"Error
2"?

YES
:
Repair
poor
contact
of
select
monitor
cartridge,

or
installation
of
different
type
select
monitor
car-

tridge
.

No
:
Data
link
system
is
normal
.

C
:
MODE
F01
AND
F05

-
FRONT
RIGHT
WHEEL
SPEED
SIGNAL

(FR)
-

Compare
speedometer
with
monitor
indications
.

"
F01
:
FR
wheelspeed
is
indicated
in
mile
per
hour
(mile/

h)
.

*
F05
:
FR
wheel
speed
is
indicated
in
kilometerper
hour

(km/h)
.

NOTE
:

The
monitoras
shown,
indicates
that
FR
wheel
speed
is

30
km/h
.

94

3. Engine Idle Speed
A: MEASUREMENT
1) Before checking idle speed, check the following:
(1) Ensure that air cleaner element is free from
clogging, ignition timing is correct, spark plugs are in
good condition, and that hoses are connected properly.
(2) Ensure that malfunction indicator light (CHECK
ENGINE light) does not illuminate.
2) Warm-up the engine.
G2M0096
3) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
CAUTION:
When connecting Subaru Select Monitor, turn ignition
switch to OFF.
4) Start the engine and measure engine speed.
NOTE:
Engine speed is indicated on Subaru Select Monitor by
selecting “MODE F04”.
G2M0097
NOTE:

When using the OBD-II general scan tool, carefully read
its operation manual.

When Subaru Select Monitor is not used, attach the
pickup sensor on tachometer (Secondary pickup type) to
#1 cylinder spark plug cord.

This ignition system provides simultaneous ignition for
#1 and #2 plugs. It must be noted that some tachometers
may register twice that of actual engine speed.
5) Check idle speed when unloaded. (With headlights,
heater fan, rear defroster, radiator fan, air conditioning, etc.
OFF)
Idle speed (No load and gears in neutral (MT) or N or
P (AT) position):
700±100 rpm
6) Check idle speed when loaded. (Turn air conditioning
switch to “ON” and operate compressor for at least one
minute before measurement.)
Idle speed [A/C“ON”, no load and gears in neutral
(MT) or N or P (AT) position]:
850±50 rpm
CAUTION:
Never rotate idle adjusting screw. If idle speed is out
of specifications, refer to General On-board Diagnosis
Table under “2-7 On-Board Diagnostics II System”.
3
2-2
3. Engine Idle Speed

2. Engine Noise
Type of sound Condition Possible cause
Regular clicking soundSound increases as engine
speed increases.Valve mechanism is defective.
Incorrect valve clearance
Worn valve rocker
Worn camshaft
Broken valve spring
Heavy and dull clankOil pressure is low.Worn crankshaft main bearing
Worn connecting rod bearing (big end)
Oil pressure is normal.Loose flywheel mounting bolts
Damaged engine mounting
High-pitched clank
(Spark knock)Sound is noticeable when
accelerating with an overload.Ignition timing advanced
Accumulation of carbon inside combustion chamber
Wrong spark plug
Improper gasoline
Clank when engine speed is
medium (1,000 to 2,000 rpm).Sound is reduced when fuel
injector connector of noisy
cylinder is disconnected.
(NOTE*)Worn crankshaft main bearing
Worn bearing at crankshaft end of connecting rod
Knocking sound when engine
is operating under idling speed
and engine is warm.Sound is reduced when fuel
injector connector of noisy
cylinder is disconnected.
(NOTE*)Worn cylinder liner and piston ring
Broken or stuck piston ring
Worn piston pin and hole at piston end of connecting rod
Sound is not reduced if each
fuel injector connector is
disconnected in turn. (NOTE*)Worn camshaft journal bore in crankcase
Squeaky sound—Insufficient generator lubrication
Rubbing sound—Defective generator brush and rotor contact
Gear scream when starting
engine—Defective ignition starter switch
Worn gear and starter pinion
Sound like polishing glass with
a dry cloth—Loose drive belt
Defective engine coolant pump shaft
Hissing sound—Loss of compression
Air leakage in air intake system, hoses, connections or
manifolds
Timing belt noise—Loose timing belt
Belt contacting case/adjacent part
Valve tappet noise—Incorrect valve clearance
NOTE*:
When disconnecting fuel injector connector, Malfunction Indicator Light (CHECK ENGINE light) illuminates and trouble code is stored in
ECM memory.
Therefore, carry out the CLEAR MEMORY MODE and INSPECTION MODE after connecting fuel injector connector. (Ref. to 2-7 On-Board
Diagnostics II System.)
78
2-3DIAGNOSTICS
2. Engine Noise