Subaru Legacy III (2000-2003 year). Manual — part 692

ABS-8

ABS

ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT (ABSCM&H/U)

17) Connect the air bleeder screws to RL and RR
caliper bodies.
18) Bleed air from brake line.

2. CHECKING THE HYDRAULIC UNIT ABS
OPERATION WITH BRAKE TESTER

1) In the case of AWD AT vehicles, install a spare
fuse with the FWD connector in the main fuse box
to simulate FWD vehicles.

2) Prepare for operating ABS sequence control.
<Ref. to ABS-9, ABS Sequence Control.>
3) Set the front wheels or rear wheels on the brake
tester and set the select lever's position at “neutral”.

4) Operate the brake tester.
5) Perform ABS sequence control.
<Ref. to ABS-9, ABS Sequence Control.>
6) Hydraulic unit begins to work; and check the fol-
lowing working sequence.

(1) The FL wheel performs decompression,
holding, and compression in sequence, and
subsequently the FR wheel repeats the cycle.
(2) The RR wheel performs decompression,
holding, and compression in sequence, and
subsequently the RL wheel repeats the cycle.

7) Read values indicated on the brake tester and
check if the fluctuation of values, when decom-
pressed and compressed, meet the standard val-
ues.

8) After checking, also check if any irregular brake
pedal tightness is felt.

(1) FWD connector

(1) Brake tester

(1) Brake tester

( 1 )

ABS00158

( 1 )

ABS00136

( 1 )

ABS00137

Front wheel

Rear wheel

Initial value

981 N

(100 kgf, 221 lb)

981 N

(100 kgf, 221 lb)

When
decom-
pressed

490 N

(50 kgf, 110 lb)

or less

490 N

(50 kgf, 110 lb)

or less

When
com-
pressed

981 N

(100 kgf, 221 lb)

or more

981 N

(100 kgf, 221 lb)

or more

ABS-9

ABS

ABS SEQUENCE CONTROL

3. ABS Sequence Control

A: OPERATION

1) Under the ABS sequence control, after the hy-
draulic unit solenoid valve is driven, the operation
of the hydraulic unit can be checked by means of
the brake tester or pressure gauge.
2) ABS sequence control can be started by diagno-
sis connector or select monitor.

1. ABS SEQUENCE CONTROL WITH DIAG-
NOSIS CONNECTOR

1) Connect diagnosis terminals to terminals No. 5
and No. 8 of the diagnosis connector beside driv-
er's seat heater unit.

2) Set the speed of all wheels at 2.75 km/h (2 MPH)
or less.
3) Turn ignition switch OFF.
4) Depress the brake pedal within 0.5 seconds af-
ter the ABS warning light goes out and hold it im-
mediately after ignition switch is turned to ON.

CAUTION:
Do not depress the clutch pedal.

NOTE:
• When the ignition switch is set to on, the brake
pedal must not be depressed.
• Engine must not operate.
5) After completion of ABS sequence control, turn
ignition switch OFF.

2. ABS SEQUENCE CONTROL WITH SE-
LECT MONITOR

NOTE:
• In the event of any trouble, the sequence control
may not be operative. In such a case, activate the
sequence control, referring to “ABS SEQUENCE
CONTROL WITH DIAGNOSIS CONNECTOR”.
<Ref. to ABS-9, ABS SEQUENCE CONTROL
WITH DIAGNOSIS CONNECTOR, OPERATION,
ABS Sequence Control.>
• When the diagnosis terminal is connected to the
diagnosis connector, the sequence control will not
operate.
1) Connect select monitor to data link connector
under driver's seat instrument panel lower cover.
2) Turn ignition switch ON.
3) Turn select monitor switch ON.
4) Put select monitor to “BRAKE CONTROL”
mode.
5) When “Function check sequence” is selected,
`ABS sequence control' will start.
6) The message `Press Brake Pedal Firmly' is dis-
played as follows:

(1) When using the brake tester, depress brake
pedal with braking force of 981 N (100 kgf, 221
lb).
(2) When using the pressure gauge, depress
brake pedal so as to make the pressure gauge
indicate 3,432 kPa (35 kg/cm

2

, 498 psi).

CAUTION:
Do not depress the clutch pedal.
7) When the message “Press YES” is displayed,
press «YES» key.
8) Operation points will be displayed on select
monitor.

(1) Diagnosis connector

(2) Diagnosis terminal

(3) 8 terminal

(4) 5 terminal

( 1 )

( 2 )

( 3 )

( 4 )

ABS00159

ABS-10

ABS

ABS SEQUENCE CONTROL

3. CONDITIONS FOR ABS SEQUENCE CONTROL

NOTE:
• When select monitor is used, control operation
starts at point A. The patterns from IGN key ON to
the point A show that operation is started by diag-
nosis connector.
• HIGH means high voltage.
• LOW means low voltage.

ABS00160

Point A

Speed of all wheels

Terminal No.5 and No.8

Ignition key switch

Stop light switch

AT ABS signal

Valve relay

FL inlet valve

FL outlet valve

FR inlet valve

FR outlet valve

RR inlet valve

RR outlet valve

RL inlet valve

Pump motor

Pressure of master cylinder

Operational
pressure of
sequence
control

Operational
pattern of
sequence
control

Operational
guide line of
sequence
control

4 km/h
(2 MPH)
or less

10 km/h (6 MPH) or less

Unit: second

Either HI or LO possible, if using select monitor.

Within 0.5

1.5

1.5

1.4

0.4

0.4

1.4

1.0

1.0

1.0

1.0

0.6

Pressure of FL wheel cylinder
Pressure of FR wheel cylinder
Pressure of RR wheel cylinder
Pressure of RL wheel cylinder

RL outlet valve

ABS warning light

HIGH

LOW

HIGH

LOW

HIGH

LOW

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ABS-11

ABS

ABS SEQUENCE CONTROL

B: SPECIFICATION

1. CONDITIONS FOR COMPLETION OF
ABS SEQUENCE CONTROL

When the following conditions develop, the ABS
sequence control stops and ABS operation is re-
turned to the normal control mode.
1) When the speed of at least one wheel reaches
10 km/h (6 MPH).
2) When terminal No. 5 or No. 8 are separated from
diagnosis terminals. (When select monitor is not
used.)
3) When the brake pedal is released during se-
quence control and the braking lamp switch is set
to off.
4) When brake pedal is depressed after ignition key
is turned to ON, and before ABS warning light goes
out. (When select monitor is not used.)
5) When brake pedal is not depressed after ignition
key is turned to ON, and within 0.5 seconds after
ABS warning light goes out. (When select monitor
is not used.)
6) After completion of the sequence control.
7) When malfunction is detected. (When select
monitor is used.)