1997 SUBARU LEGACY ABS

SERVICE
PROCEDURE
Iwz7oo1
4-4

25
.
ABS
Control
Module
and
Hydraulic
Control
Unit
(ABSCM&H/U)
[ABS
5
.3i
Type]
-
27
.
G
Sensor
(ABS
5
.3i
Type)

E
:
INSTALLATION

1)
Install
ABSCM&H/U
.

CAUTION
:

Confirm
that
the
specifications
of
the
ABSCM&H/U
con-

forms
to
the
vehicle
specifications
.

Tightening
torque
:

18
f
5
N~m
(1
.8
±
0
.5
kg-m,
13
.0
±
3
.6ft-Ib)
2)
Connect
brake
pipes
to
their
correct
ABSCM&H/U
con-

nections
.
<
Ref
.
to
[W18A4]
.*10
>

3)
Using
cable
clip,
secure
ABSCM&H/U
harness
to

bracket
.

4)
Connect
connector
to
ABSCM&H/U
.

CAUTION
:

9
Be
sure
to
remove
all
foreign
matter
from
inside
the

connector
before
connecting
.

9
Ensure
that
the
ABSCM&H/U
connetor
is
securely

locked
.

5)
Install
air
intake
duct
.

6)
Connect
ground
cable
to
battery
.

7)
Bleed
air
from
the
brake
system
.

26
.
ABS
Sensor
(ABS
5
.3i
Type)

<
Ref
.
to
4-4
[W1400]
.*1
>

27
.
G
Sensor
(ABS
5
.3i
Type)

Ref
.
to
4-4
[W2400]
.*5
>

15

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

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

2
.
Pre-inspection

B
:
ELECTRICAL
INSPECTION

1
.
WARNING
LIGHT
ILLUMINATION
PATTERN

START

ON
r~
ON
OFF
Ignition
key
switch

Illuminates
.

Goes
out
.
Goes
out
.
ABS
warning
light1.5s
4
111

B4M0781A

1)
When
the
ABS
warning
light
does
not
illuminate
in

accordance
with
this
illumination
pattern,
there
must
be
an
electrical
malfunction
.

2)
When
the
ABS
warning
light
remains
constantly
OFF,

repair
the
ABS
warning
light
circuit
or
diagnosis
circuit
.

.
to
4-4d
[T7A0]
.*10>

NOTE
:

Even
though
the
ABS
warning
light
does
not
go
out
1
.5

seconds
after
it
illuminates,
the
ABS
system
operates
nor-

mally
when
the
warning
light
goes
out
while
driving
at

approximately
12
km/h
(7
MPH)
.
However,
the
Anti-lock

brakes
do
not
work
while
the
ABS
warning
light
is
illumi-

nated
.

3

4-4d
[Taoo1
BRAKES
[ABS
5
.31
TYPE]

3
.
Electrical
Components
Location

3
.
Electrical
Components
Location

84M
1225A

ABS
control
module
and
hydraulic
control
unit

(ABSCM&H/U)
~2
Proportioning
valve

03
Diagnosisconnector

~4
ABS
warning
light

~5
Data
link
connector
(for
Subaru
select
monitor)

~6
Transmission
control
module
(only
AT
vehicle)

Tone
wheel

%
ABS
sensor

Wheel
cylinder

(*
G
sensor
(only
AWD
vehicle)

~t
Brake
switch

#
Master
cylinder

4

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

3
.
Electrical
Components
Location

O

.a
4

.OeF
r~
~
12p
Y1
"
N,
~
'
o~
~~
m
en
.
7
2
1
O

---~
4

~-
)~
134M1226A
134100230D
I
134M0786C

7I
I
~
~
~l
\

°o

i

5
~-~s~v

'
Diag
.
terminal

3
terminal
6
terminal

B4M0646D
1341002311341002
1)
311)
84M06451)

5

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

4
.
Schematic

4
.
Schematic

10

14

BATTERY
16

-----I

---
IGN

17
----I

=
O_
.__J

C5
19

U6

--
-
------
H
!
20

-----------
g

10

1
-
~
11

----------
----
r
12
23
`
"
...
.,`
@
.

Twisted
w
ire

B
4M1227A

ABS
control
module
and
hydraulic
control
unit

(ABSCM&H/U)

~2
ABS
control
module
area

~3
Valve
relay

~a
Motor
relay

~5
Motor

06
Front
left
inlet
solenoid
valve

07
Front
left
outlet
solenoid
valve

~8
Front
right
inlet
solenoid
valve

Front
right
outlet
solenoid
valve
~o
Rear
left
inlet
solenoid
valve

Rear
left
outlet
solenoid
valve

g
Rear
right
inlet
solenoid
valve

Rear
right
outlet
solenoid
valve

~a
Transmission
control
module
(only
AT
model)

~5
Diagnosis
connector

~s
Data
link
connector

ABS
warning
light

Qe
Stop
light
switch

Stop
light

~o
G
sensor
(only
AWD
model)

Front
left
ABS
sensor

~2
Front
right
ABS
sensor

Rear
left
ABS
sensor

Rear
right
ABS
sensor

6

4-4d
[TSOi1
BRAKES
[ABS
5
.31
TYPE]

5
.
Control
Module
I/OSignal
5
.
Control
Module
I/O
Signal

1
.
I/O
SIGNAL
VOLTAGE

ABS
control
moduleand
hydraulic
control
unit
connector

Ell

30000000

00000

Connector
switch

i

F49

1
21314
5
1
6
1
7
1
8
1
9
1
10
1
11
1
12
1
13
1
14
1
15

16
171819
20
2122
232425
26
1
27
1
28
1
29
1
30
1
31
1

84M1228A

NOTE
:

*
The
terminal
numbers
in
the
ABS
control
module
and

hydraulic
control
unit
connector
are
as
shown
in
the
fig-

ure
.

9
When
the
connector
is
removed
from
the
ABSCM&H/U,

the
connector
switchcloses
the
circuit
between
terminal

No
.
21
andNo
.
23
.
The
ABS
warning
light
illuminates
.

8