Subaru Legacy III (2000-2003 year). Service manual — part 703

ABS-30

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

6

CHECK BATTERY SHORT OF ABS WARN-
ING LIGHT HARNESS.
1) Turn ignition switch to OFF.
2) Measure voltage between connector (F45)

or (F2) and chassis ground.

Connector & terminal

LHD: (F45) No. 5 (+) — Chassis ground
(

−−−−

):

RHD: (F2) No. 18 (+) — Chassis ground
(

−−−−

):

Is the measured value less than the speci-
fied value?

3 V

Go to step 7.

Repair wiring har-
ness.

7

CHECK BATTERY SHORT OF ABS WARN-
ING LIGHT HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between connector (F45)

or (F2) and chassis ground.

Connector & terminal

LHD: (F45) No. 5 (+) — Chassis ground
(

−−−−

):

RHD: (F2) No. 18 (+) — Chassis ground
(

−−−−

):

Is the measured value less than the speci-
fied value?

3 V

Go to step 8.

Repair wiring har-
ness.

8

CHECK GROUND CIRCUIT OF ABSCM&H/U.
Measure resistance between ABSCM&H/U
and chassis ground.

Connector & terminal

(F49) No. 23 — GND:

Is the measured value less than the specified
value?

0.5

Ω

Go to step 9.

Repair
ABSCM&H/U
ground harness.

9

CHECK WIRING HARNESS.
Measure resistance between connector (F45)
or (F2) and chassis ground.

Connector & terminal

LHD: (F45) No. 5 — Chassis ground:
RHD: (F2) No. 18— Chassis ground:

Is the measured value less than the specified
value?

0.5

Ω

Go to step 10.

Repair harness/
connector.

10

CHECK POOR CONTACT IN CONNECTORS.
Turn ignition switch to OFF.
Is there poor contact in connectors between
combination meter and ABSCM&H/U?

There is no poor contact.

Replace
ABSCM&H/U.
<Ref. to ABS-6,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>

Repair connector.

Step

Value

Yes

No

ABS-31

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

MEMO:

ABS-32

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

B: ABS WARNING LIGHT DOES NOT GO OFF.

DIAGNOSIS:
• ABS warning light circuit is open or shorted.
TROUBLE SYMPTOM:
• When starting the engine and while ABS warning light is kept ON.
WIRING DIAGRAM:

ABS00308

24

1

23

5

4

18

20

22

4

ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT

F49

B82

B81

8

DIAGNOSIS
TERMINAL

DIAGNOSIS
CONNECTOR

B36

B4 B5 B6

A4 A5 A6

C5 C6

F6

D4 D5 D6

F1

H1

C4

G6

G1

C2

K1

M1 M2

K6

L1

D1 D2

A1 A2
B1 B2

I6

J6

L2

I1

J1

H6

M4 M5 M6

L4 L5 L6

N5 N6

O4 O5 O6

N4

P4 P5

N2

O1 O2

P1 P2

N3

O3

P3

P6

A3

B3

C3

E4 E5 E6

E1 E2

i10

1 2 3 4 5 6 7

8 9 10 11 12 13 14

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

16 17 18 19 20 21 22

27 28 29 30 31

23

24

25

26

F49

B82

1 2
4 5 6 7

3
8

i12

1 2 3

4 5 6

7 8 9 10 11 12 13 14

NO

. 8 30A

NO

. 18 15A

BATTERY

SBF-1 100A

SBF-3 50A

SBF-4 50A

IGNITION
SWITCH

COMBINATION
METER

ABS

WARNING

LIGHT

B:

i11

C:

i12

A:

i10

G1

i1

B36

GENERATOR

B5

IGNITION
RELAY

NO

. 5 15A

F45

1 2 3

4 5 6 7

8 9 10 11

12 13 14 15 16

TB

1

*

2

*

3

*

4

*

RHD

LHD

1

*

2

*

3

*

:TURBO A8
NA C3

: LHD

RHD

: TURBO B2
NA C11

: TURBO
ENGINE
MODEL

4

*

: LHD

RHD

TB

F2

F45

B100

B62

1 2 3
8 9 10

4

11 12 13 14 15 16

5 6 7

B:

i11

F2

3 4

1 2

8 9 10 11

12 13 14 15 16 17 18 19 20 21 22 23 24

5 6

7

ABS-33

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK INSTALLATION OF ABSCM&H/U
CONNECTOR.
Turn ignition switch to OFF.
Is ABSCM&H/U connector inserted into
ABSCM until the clamp locks onto it?

Connector is locked securely.

Go to step 2.

Insert ABSCM&H/
U connector into
ABSCM&H/U until
the clamp locks
onto it.

2

CHECK DIAGNOSIS TERMINAL.
Measure resistance between diagnosis termi-
nals (B81) and chassis ground.

Terminals

Diagnosis terminal (A) — Chassis
ground:
Diagnosis terminal (B) — Chassis
ground:

Is the measured value less than the specified
value?

0.5

Ω

Go to step 3.

Repair diagnosis
terminal harness.

3

CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal (B81) to diag-

nosis connector (B82) No. 8.

3) Disconnect connector from ABSCM&H/U.
4) Measure resistance between ABSCM&H/U

connector and chassis ground.

Connector & terminal

(F49) No. 4 — Chassis ground:

Is the measured value less than the speci-
fied value?

0.5

Ω

Go to step 4.

Repair harness
connector
between
ABSCM&H/U and
diagnosis connec-
tor.

4

CHECK GENERATOR.
1) Start the engine.
2) Idle the engine.
3) Measure voltage between generator and

chassis ground.

Terminal

Generator B terminal (+) — Chassis
ground (

−−−−

):

Is the measured value within the specified
range?

10 - 15 V

Go to step 5.

Repair generator.
H4 engine model:
<Ref. to
SC(H4SO)-14,
Generator.>
H6 engine model:
<Ref. to
SC(H6DO)-14,
Generator.>

5

CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
Is there poor contact at battery terminal?

There is no poor contact.

Go to step 6.

Repair battery ter-
minal.

6

CHECK POWER SUPPLY OF ABSCM.
1) Disconnect connector from ABSCM&H/U.
2) Start engine.
3) Idle the engine.
4) Measure voltage between ABSCM&H/U

connector and chassis ground.

Connector & terminal

(F49) No. 1 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 - 15 V

Go to step 7.

Repair
ABSCM&H/U
power supply cir-
cuit.

7

CHECK WIRING HARNESS.
1) Disconnect connector (F45) from connector

(B62).

2) Turn ignition switch to ON.

Does the ABS warning light turn on?

ABS warning light remains off. Go to step 8.

Repair front wiring
harness.