Subaru Legacy III (2000-2003 year). Manual - part 737

VDC-16

VDC

ABS SEQUENCE CONTROL

4. 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) Within 0.5 seconds after the ABS and VDC
warning light goes out, depress the brake pedal
and hold it immediately 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 VDC-16, 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
beside 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

VDC-17

VDC

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 diagnosis connector.
• HIGH means high voltage.
• LOW means low voltage.

VDC00086

Speed of all wheels

Terminal No. 5 and No. 8

Ignition key switch

ABS warning light

VDC warning light

VDC. OFF indicator light

Pressure sensor signal

AET

AEB

AEC

EAM

Valve relay

Secondary cut valve

Primary cut valve

Secondary suction valve

Primary suction valve

FL outlet valve

FL inlet valve

FR outlet valve

FR inlet valve

RR outlet valve

RR inlet valve

RL outlet valve

RL inlet valve

Pump motor

Pressure of master cylinder

Pressure of RR wheel cylinder

Pressure of FR wheel cylinder

Pressure of RL wheel cylinder 

Pressure of FL wheel cylinder

VDC operation indicator light

Operational
guide line of
sequence 
control

Operational 
pattern of 
sequence 
control

Operational 
pressure of
sequence 
control

2.75 km/h (2 MPH) or less

LOW

OFF

OFF

LIGHT

OFF

LIGHT

LOW

HIGH

LOW

HIGH

LOW

HIGH

OFF

ON

OFF

OFF

OFF

OFF

OFF

ON

OFF

ON

OFF

OFF

ON

0.4s

1s

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

ON

OFF

OFF

LIGHT

OFF

ON

ON

1.5s

1.5s

1.4s

1.0s

1.4s

0.6s

1s

Point A

10 km/h (6 MPH) or less

Within 0.5s

VDC-18

VDC

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.)

VDC-19

VDC

VDC SEQUENCE CONTROL

5. VDC Sequence Control

A: OPERATION

1) Under the VDC 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) VDC sequence control can be started by diagno-
sis connector or select monitor.

1. VDC 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) Turn ignition switch ON and start engine imme-
diately, confirming that ABS and VDC warning light
goes ON and then OFF. After ABS and VDC warn-
ing light goes OFF, within 0.5 seconds depress the
brake pedal once, then within 3 second depress the
brake pedal twice more and release it.

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 operate.
• If the VDC sequence control does not start, do
the procedure over again.
5) After completion of VDC sequence control, turn
ignition switch OFF.

2. VDC 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 “VDC SEQUENCE
CONTROL WITH DIAGNOSIS CONNECTOR”.
<Ref. to VDC-19, VDC SEQUENCE CONTROL
WITH DIAGNOSIS CONNECTOR, OPERATION,
VDC 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
beside 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) Select  “VDC Check Mode” in {Function check
sequence} menu to start `VDC sequence control'.

CAUTION:
Do not depress the clutch pedal.
6) When the message “Press YES” is displayed,
press «YES» key.
7) 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