1997 SUBARU LEGACY speed sensor

BRAKES
IM13-21
4-4
13
.
Anti-lock
Brake
System
(ABS)
[5
.3i
Type]

2
.
FUNCTIONS
OF
SENSORS
AND
ACTUATORS

Name
Function

ABS
control
moduleand
hydraulic
ABSCM-
e
Calculates
and
determine
the
conditionsof
the
wheels
and
body
from
control
unit
(ABSCM&H/U)
section
the
wheel
speedsand
makes
a
proper
decision
suitable
for
the
current
situation
to
control
the
hydraulic
unit
.

In
the
ABS
operation
mode,
the
module
outputs
a
cooperative
control
signal
to
the
AT
control
module
.
(AT
vehicles
only)

Whenever
the
ignition
switch
is
placed
at
ON,
the
module
makes
a
self
diagnosis
.
When
anything
wrong
is
detected,
the
module
cuts
off
the
system
.

Communicates
with
the
Subaru
select
monitor
.

H/U-section
In
the
ABS
operation
mode,
the
H/U
changes
fluid
passages
to
control

the
fluid
pressure
of
the
wheel
cylinders
in
response
to
an
instruction
from
the
ABSCM
.

The
H/U
also
constitutes
thebrake
fluid
passage
from
the
master
cylin-
der
to
the
wheel
cylinders
together
with
pipings
.

Valve
relay-
Serves
asa
power
switch
for
the
solenoid
valve
and
motor
relay
coil
in
section
response
to
an
instruction
from
the
ABSCM
.

Motor
relay-
Serves
as
a
power
switch
for
the
pump
motor
in
response
to
an
instruc-
section
tion
from
the
ABSCM
.

Wheel
speed
sensor
(ABS
sensor)
Detects
the
wheel
speed
in
terms
of
a
change
in
the
magnetic
flux
den-
sity
passingthrough
the
sensor,
converts
it
into
an
electrical
signal,
and
outputs
the
electrical
signal
to
the
ABSCM
.

Tone
wheel
Gives
a
change
in
the
magnetic
flux
density
by
the
teeth
around
the
tone
wheel
to
let
the
ABS
sensor
generate
an
electrical
signal
.

G
sensor
(AWD
vehicle
only)
Detects
a
change
in
G
in
the
longitudinal
direction
of
the
vehicle
and
outputs
it
to
the
ABSCM
in
terms
of
a
change
in
voltage
.

Stop
light
switch
Transmits
the
information
on
whether
the
brakepedal
is
depressed
or
not
to
the
ABSCM
for
use
as
a
condition
in
determining
ABS
operation
.

ABS
warning
light
Alerts
the
driver
to
an
ABS
fault
.
When
the
diagnosis
connector
and
diagnosis
terminal
are
connected,
the
light
flashes
to
indicate
a
trouble
codes
in
response
to
an
instruction
from
the
ABSCM
.

AT
control
module
(TCM)
(AT
vehicles
only)
Provides
shift
controls
(fixing
the
speed
at
3rd
or
changing
front
and
rear
wheel
transmission
characteristics
on
4WD
vehicle)
in
response
to
an
instruction
fromthe
ABSCM
.

4-4
[M13-51
BRAKES
13
.
Anti-lock
Brake
System
(ABS)
[5
.3i
Type]

5
.
ABSCONTROLMODULEAND
HYDRAULIC
CONTROL
UNIT
(ABSCM&H/U)

*
ABS
CONTROL
MODULE
SECTION
(ABSCM)

The
ABSCM
is
a
digital
control
type
electronic
control
module
accommodating
two
microcontrol

modules
(MCMs)
;
master
and
slave
.
Both
MCMs
process
the
same
program
and
monitor
the

respective
outputs,
and
when
a
mismatch
occurs,
cut
off
the
system
to
activate
the
fail-safe
func-

tion
.

A
maximum
of
3
trouble
codes
are
stored
in
the
EEP
ROM
and
if
3or
more
areas
fail,
then
only
the

3
most
recent
failures
are
stored
.
The
trouble
codes
remain
stored
until
they
are
erased
.

This
ABSCM
inducesa
sequence
control
pattern
and
facilitates
the
checking
of
the
hydraulic
unit
.

"
ABS
control

Based
on
the
four
wheel
speed
signals,
the
ABSCM
calculates
a
simulated
body
speed
or
body

deceleration
rate,
whilereferencing
the
G
sensor
output
asan
auxiliary
means,
and
compares
them
with
the
wheel
speeds
and
wheel
deceleration
rates
.
If
it
determines
that
the
wheels
are

about
to
lock,
it
controls
the
solenoidvalve
or
motor
pump
of
the
H/U
to
adjustthe
brake
fluid
pres-

sures
that
act
on
the
wheel
cylinders,
thereby
preventing
the
wheels
from
locking
.

The
ABSCM
controls
the
right
and
left
front
wheel
fluid
pressures
independently
and
controls
the

rear
wheel
fluid
pressures
on
the
basis
of
the
wheel
which
is
more
likely
to
lock
(Select-low
control)
.

"
Select
monitor
associated
functions

The
Subaru
select
monitor
may
beused
to
perform
the
following
operations
.

O
To
read
out
analogdata
Toread
out
ON/OFF
data

O
Toread
out
or
erase
trouble
code

O
Toread
out
status
information
in
the
event
of
trouble
(Freeze
frame
data)

O
To
initiate
ABS
sequence
control
pattern

"
Indication
functions

The
ABS
warning
light
can
be
made
to
indicate
the
following
three
states
.

O
ABS
trouble

Flashes
to
indicate
trouble
codes
in
diagnosis
mode
.

O
Valve
ON/OFF
when
sequence
control
pattern
isin
effect

6

BRAKES
[ABS
5
.31
TYPE]
'
[T501]
4-4d

5
.
Control
Module
I/O
Signal

Terminal

N
Input/Output
signal
Contents
o
.

_)
Measured
value
andmeasuring
conditions

ABS
Front
left
wheel
9-10

sensor'2
Front
right
wheel
11-12
0
.12
-
1
V
(Wheel

speed
Rear
left
wheel
7-8
(When
it
is
20Hz
.)

sensor)
Rear
right
wheel
14-15

Valve
relay
power
supply
24-23
10
-
15
Vwhen
ignition
switch
is
ON
.

Motor
relay
power
supply
25-23
10
-
15
Vwhen
ignition
switch
is
ON
.

G
sensor'2
Power
supply
30-28
4
.75
-
5
.25
V

(AWD
model
ground
28
-

only)
output
6-28
2
.3f0
.2
V
when
vehicle
isin
horizontal
position
.

Stop
light
switch*1
2-23
Less
than
1
.5
V
when
the
stop
light
is
OFF
and,10
-
15
V

when
thestop
light
is
ON
.

ABS
warning
light`2
21-23
Less
than
1.5
V
during
1
.5
seconds
when
ignition
switch
is

ON,and
10
-
15
V
after
1.5
seconds
.

AT
ABS
signal'2

(AT
model
only)
31-23
Less
than
1
.5
V
when
the
ABS
control
does
not
operate
still

and
more
than5
.5
V
when
ABS
operates
.

ABS
operation
signal
monitor*2
3--23
Less
than
1
.5
V
when
the
ABS
control
does
not
operate
still

and
more
than5
.5
V
when
ABS
operates
.

Select
Data
is
received
.
20-23
Less
than
1
.5
V
when
no
data
is
received
.

monitor'2
Data
is
sent
.
5--23
4
.75
-
5
.25
V
when
no
data
is
sent
.

ABS
Terminal
No
.
3
29-23
10
-
15
V
when
ignition
switch
is
ON
.
diagnosis

connector*2
Terminal
No
.
6
4-23
10
-
15
V
when
ignition
switch
is
ON
.

Power
supply'1
1-23
10
-
15
V
when
ignition
switch
is
ON
.

Grounding
line
23
-

Grounding
line
~26

*1
:
Measure
the
I/O
signal
voltage
after
removing
the
connector
from
the
ABSCM&H/U
terminal
.
'2
:
Measure
the
I/O
signal
voltage
at
connector
(F2)
or
(Fi)
.

9

4-4d
[TSOO1
BRAKES
[ABS
5
.31
TYPE]

9
.
Select
Monitor
Function
Mode

o

°~°

poo

I
\G2M0096

9
.
Select
Monitor
Function
Mode

Applicable
cartridge
of
select
monitor
:
No
.
498346300

A
:
LIST
OF
FUNCTION
MODE

1,
F
MODE
(ROM
ID,
ANALOG
DATA
ARE

DISPLAYED
.)

Function
code
it
M
i
C
easur
ng
ems
ontents
to
be
monitored
Scroll
Ref
.
to
Code
Abbreviation

F00
ROM
ID
ECM
identification
ROM
ID
number
of
ECM
is
read
and
enabled
possible
[T9B0]*10
communication
state
is
displayed
.

F01
FRFR
wheel
speedWheel
speed
detected
by
the
FR
ABS
sensor
is
possible
[T9COJ*10
(mile/h)
displayed
in
mile/h
.

F02
FLFL
wheelspeed
Wheel
speed
detected
by
the
FL
ABS
sensor
is
Possible
[T9D0]x10
(mile/h)
displayed
in
mile/h
.

F03
RR
RR
wheel
speedWheelspeed
detected
by
the
RR
ABS
sensor
is
possible
[T9E0]*10
(mile/h)
displayed
in
mile/h
.

F04
RLRL
wheel
speed
Wheel
speed
detected
by
the
RL
ABS
sensor
is
possible
[T9F0]*10
(mileJh)
displayed
in
mile/h
.

F05
FRFR
wheelspeed
Wheel
speed
detected
by
the
FR
ABS
sensor
is
possible
[T9C0j*10
(km/h)
displayed
in
km/h
.

F06
FL
FL
wheel
speedWheelspeed
detected
by
the
FL
ABS
sensor
is
possible
[T9D0]*10
(km/h)
displayed
in
km/h
.

F07
RRRR
wheel
speedWheelspeed
detected
by
the
RR
ABS
sensor
is
Possible
[T9E0]*10
(km/h)
displayed
in
km/h
.

F08
RLRL
wheel
speedWheelspeed
detected
by
the
RL
ABS
sensor
is
possible
[T9FO]w10
(km/h)
displayed
in
km/h
.

F09
BLS
Stop
light
switch
Stop
light
switch
monitor
voltage
is
displayed
.
Possible
[T9G0]d10
monitor

G
sensor
output
Refers
to
vehicleacceleration
detecting
by
the
[T9H0]*10
F10
G-SENS
voltage
(V)
analog
G
sensor
.
It
appears
on
theselect
moni-
Possible

for
display
in
volts
.

90

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

9
.
Select
Monitor
Function
Mode

4
.
FC
MODE
(TROUBLE
CODES
ARE
ERASED
.)

Function
code

Code
Abbreviation
Measuring
items
Contents
to
be
monitored
Scroll
Ref
.
to

Historyoftrouble
FCOD~CLR
Function
of
clearing
trouble
code
.
Possible
[T9J0]*10
codes
is
erased
.

5
.
FD
MODE
(ABS
SEQUENCE
CONTROL
MODE)

Function
code
M
i
Code
Abbreviation
easurng
items
Contents
to
be
monitored
Scroll
Ref
.
to

FD1A~CHK
ABS
sequence
con-
Perform
ABS
sequence
control
by
operating
impossible
4-4

tral
valve
and
pump
motor
sequentially
.
[W25D2]*10
6
.
FE
MODE
(FREEZE
FRAME
DATA)

NOTE
:

9
Data
stored
at
the
time
of
trouble
occurrence
is
shown

on
display
.

Each
time
trouble
occurs,
the
latest
information
is

stored
in
the
freeze
frame
data
in
memory
.

Function
code
Measuring
items
Contents
to
be
monitored
Scroll
Ref
.
to
Code
Abbreviation

FE1
FR
FR
wheel
speedWheelspeed
detected
by
the
FR
ABS
sensor
is
possible
[T9K0]*10
(milelh)
displayed
in
mile/h
.

FE2
FL
FL
wheelspeed
Wheelspeed
detected
by
the
FL
ABS
sensor
is
possible
[T9L0]*10
(mile/h)
displayed
in
mile/h
.

FE3
RRRR
wheelspeed
Wheelspeed
detected
by
the
RR
ABS
sensor
is
possible
[T9MO]*10
(milelh)
displayed
in
mite/h
.

FE4
RLRL
wheel
speedWheel
speed
detected
by
the
RL
ABS
sensor
is
possible
[T91V0]*10
(mile/h)
displayed
in
mite/h
.

FE5
FRFR
wheel
speedWheelspeed
detected
by
the
FR
ABS
sensor
is
possible
[T9K0]fr10
(km/h)
displayed
in
km/h
.

FE6
FL
Ft
wheel
speed
Wheel
speed
detected
by
the
FL
ABS
sensor
is
Possible
[T9L0]~10
(km/h)
displayed
in
km/h
.

FE7
RRRR
wheel
speed
Wheel
speed
detected
by
the
RR
RBS
sensor
is
possible
[T9M0]*10
(km/h)
displayed
in
km/h
.

FE8
RLRL
wheel
speedWheelspeed
detected
by
the
RL
ABS
sensor
is
possible
[T9N0]t`r10
(km/h)
displayed
in
km/h
.

FE13
POWER
ABSCM&H/U
power
Power
(in
volts)
supplied
to
ABSCM&H/U
Possible
[T900]*10
supply
voltage
(V)
appears
on
the
select
monitor
display
.

G
sensor
output
Refers
to
vehicleacceleration
detected
by
the

FE14
G-SENS
voltage
(V)
analog
G
sensor
.
It
appears
on
the
select
moni-
Possible
[T9P0]*10

for
display
in
volts
.

MM
Motor
relay
monitor
LED
1
comes
on
when
motor
relay
is
on
.

131
Stop
light
switch
LED
2
comes
on
with
the
stop
light
switch
on
(with
the
brakepedal
depressed)
.
FE15
ATAT
ABS
signal
LED
3
comes
an
when
ABS
control
is
on
.
Possible
[T9Q0]~10

CM
CCM
signal
LED
4
comes
on
when
ABS
control
is
on
.

AO
ABS
control
LED
5
comes
on
when
ABS
control
is
on
.

FE16
CODE
trouble
code
The
most
recent
trouble
code
appears
on
select
Possible
(T9R0]*10
monitor
display
.

92

4-4d
[T9F0]
BRAKES
[ABS
5
.3i
TYPE]
9
.
Select
Monitor
Function
Mode

RL
(F08)

50
km/h

B4M0925

BLS
(FQ9)

12
.00
V

B4M1265

G-SENS
(F
10)
2
.30
V

B4M0927I

F
:
MODE
F04
AND
F08

-
REAR
LEFT
WHEEL
SPEED
SIGNAL
(RL)
-

Compare
speedometer
with
monitor
indications
.

"
F04
:
RL
wheelspeed
is
indicated
in
mile
per
hour
(mile/

h)
.

*
F08
:
RL
wheel
speed
is
indicated
in
kilometerper
hour

(km/h)
.

NOTE
:

The
monitoras
shown,
indicates
that
RL
wheelspeed
is

50km/h
.

G
:
MODE
F09

-
STOP
LIGHT
SWITCH
MONITOR
(BLS)
-

9
Stop
light
switch
monitor
voltage
is
displayed
.

H
:
MODE
F10

-
G
SENSOR
OUTPUTVOLTAGE
(G-SENS)
-

*
Refers
to
vehicle
accelerationdetecting
bythe
analog

G
sensor
.
It
appears
on
the
select
monitor
display
in
volts
.

NOTE
:

Only
AWD
model

96

4-4d
[T1oHyl
BRAKES
[ABS
5
.3i
TYPE]

10
.
Diagnostics
Chart
with
Select
Monitor

FR
(F05)

30
km/h

B4M0922

I1
0H1
(CHECK
OUTPUT

SELECT
MONITORF

ABS
SENSOR
USING

Read
the
ABS
sensoroutput
corresponding
to
the
faulty

system
in
the
select
monitor
function
mode
.

NOTE
:

The
select
monitor
display
shows
that
the
front
right
wheel

is
rotating
at
30km/h
.

CHECK
:
Does
the
speed
indicated
on
the
display

change
in
response
to
the
speedometer

reading
during
acceleration/deceleration

when
the
steering
wheel
isin
the
straight-

ahead
position?

YES
:
Go
to
step
10H2
.

No
:
Go
to
step
10H9
.

1OH2
I
HECK
INSTALLATION
OF
ABS
SENSOR
.

Tighteningtorque
:

32
f
10
N~
m
(3.3
f
1
.0
kg-m,
24
±
7
ft-Ib)

CHECK
:
Are
the
ABS
sensor
installation
bolts
tight-

ened
securely?

,rES
:
Go
to
step
10H3
.

No
:
Tighten
ABS
sensor
installation
bolts
securely
.

10H3
I
CHECK
INSTALLATION
OFTONE
WHEEL
.

Tightening
torque
:

13±3
N~m
(1
.3±0
.3
kg-m,
9±2
.2
ft-Ib)

CHECK
:
Are
the
tone
wheel
installation
bolts
tight-

ened
securely?

ves
:
Go
to
step
10H4
.

No
:
Tightentone
wheel
installation
bolts
securely
.

114

4-4d
[T1
01-111
BRAKES
[ABS
5
.31
TYPE]

10
.
Diagnostics
Chart
withselect
monitor

FR
(F05)

30
km/h

B4M0922

(SELECT

CHECK
OUTPUT
MONITOR

F
ABS
SENSOR
USING

Read
the
ABS
sensor
output
corresponding
to
the
faulty

system
in
the
select
monitor
function
mode
.

NOTE
:

The
select
monitor
display
shows
that
the
front
right
wheel

is
rotating
at
30
km/h
.

CHECK
:
Does
the
speed
indicated
on
the
display

change
in
response
to
the
speedometer

reading
during
acceleration/deceleration

when
the
steering
wheel
is
in
the
straight-

ahead
position?

Go
to
step
1012
.

No
:
Go
to
step
10L8
.

I1011-2
CHECK
POOR
CONTACT
IN
CONNECTORS
.

Turn
ignition
switch
to
OFF
.

CHECK
:
Is
there
poor
contact
in
connectors
between

ABSCM&HfU
and
ABS
sensor?

,rES
:
Repair
connector
.

No
:
Go
to
step
10L3
.

10L3
I
CHECK
SOURCES
OF
SIGNAL
NOISE
.

CHECK
:
Is
the
cartelephone
orthe
wireless
transmit-

ter
properly
installed?

Go
to
step
10L4
.

No
:
Properly
install
the
car
telephone
or
the
wireless

transmitter
.

1
10L4
I
CHECK
SOURCES
OF
SIGNAL
NOISE
.

Are
noise
sources
(such
as
an
antenna)

installed
near
the
sensorharness?

Install
the
noise
sources
apartfromthe
sensor

harness
.

No
:
Go
to
step
10L5
.

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