Subaru Legacy III (2000-2003 year). Manual - part 715

ABS-78

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

7

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM&H/U 

connector and chassis ground.

Connector & terminal

(F49) No. 6 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 8.

Repair harness 
between G sensor 
and ABSCM&H/U.

8

CHECK GROUND SHORT OF HARNESS.
Measure resistance between ABSCM&H/U 
connector and chassis ground.

Connector & terminal

(F49) No. 28 — Chassis ground:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 9.

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

9

CHECK G SENSOR.
1) Turn ignition switch to OFF.
2) Remove G sensor from vehicle.
3) Connect connector to G sensor.
4) Connect connector to ABSCM&H/U.
5) Turn ignition switch to ON.
6) Measure voltage between G sensor con-

nector terminals.

Connector & terminal

(R70) No. 2 (+) — No. 3 (

−−−−

):

Is the measured value within the specified 
range  when G sensor is horizontal?

2.1 - 2.5 V

Go to step 10.

Replace G sen-
sor.  <Ref. to ABS-
21, G Sensor.> 

10

CHECK G SENSOR.
Measure voltage between G sensor connector 
terminals.

Connector & terminal

(R70) No. 2 (+) — No. 3 (

−−−−

):

Is the measured value within the specified 
range when G sensor is inclined forward to 
90

°

?

3.7 - 4.1 V

Go to step 11.

Replace G sen-
sor.  <Ref. to ABS-
21, G Sensor.>

11

CHECK G SENSOR.
Measure voltage between G sensor connector 
terminals.

Connector & terminal

(R70) No. 2 (+) — No. 3 (

−−−−

):

Is the measured value within the specified 
range when G sensor is inclined backward to 
90

°

?

0.5 - 0.9 V

Go to step 12.

Replace G sen-
sor.  <Ref. to ABS-
21, G Sensor.>

12

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connector between 
ABSCM&H/U and G sensor?

There is no poor contact.

Go to step 13.

Repair connector.

13

CHECK ABSCM&H/U.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the DTC.

Is the same DTC still being output?

Same DTC is not indicated.

Go to step 14.

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

Step

Value

Yes

No

ABS-79

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

14

CHECK ANY OTHER DTC APPEARANCE.
Are other DTC being output?

Other DTC is not indicated.

A temporary poor 
contact.

Proceed with the 
diagnosis corre-
sponding to the 
DTC.

Step

Value

Yes

No

ABS-80

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR

13.Diagnostics Chart with Subaru Select Monitor

A: COMMUNICATION FOR INITIALIZING IMPOSSIBLE 

DIAGNOSIS:
• Faulty harness connector
TROUBLE SYMPTOM:
• ABS warning light remains on.
WIRING DIAGRAM:

ABS00313

BATTERY

1

23

20

5

ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT

F49

NO

. 18 15A

SBF-4 50A

SBF-1 100A

DATA LINK
CONNECTOR

5

4

B40

21

22

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

F2

1

2

B40

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

GENERATOR

IGNITION 
SWITCH

F45

1 2
8 9

3

4 5 6 7

10 11 12 13 14 15 16

F49

3 4

1 2

8 9 10 11

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

5 6

7

RHD

LHD

1

*

1

*

2

*

F45

LHD

:

F2

RHD

2

*

B62

LHD

:

B100

RHD

:

ABS-81

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR

Step

Value

Yes

No

1

CHECK IGNITION SWITCH. 
Is ignition switch to ON? 

Ignition switch is to ON.

Go to step 2.

Turn ignition 
switch to ON, and 
select ABS mode 
using the select 
monitor.

2

CHECK BATTERY.
1) Turn ignition switch to OFF.
2) Measure battery voltage.

Does the measured value exceed the spec-
ified value?

11 V

Go to step 3.

Charge or replace 
battery.

3

CHECK BATTERY TERMINAL.
Is there poor contact at battery terminal? 

There is no poor contact.

Go to step 4.

Repair or tighten 
battery terminal.

4

CHECK COMMUNICATION OF SELECT 
MONITOR.
1) Turn ignition switch to ON.
2) Using the select monitor, check whether 

communication to other systems can be 
executed normally.
Are the name and year of the system dis-
played on the select monitor?

Name and year of the system 
are displayed.

Go to step 7.

Go to step 5.

5

CHECK COMMUNICATION OF SELECT 
MONITOR.
1) Turn ignition switch to OFF.
2) Disconnect ABSCM&H/U connector.
3) Check whether communication to other 

systems can be executed normally.
Are the name and year of the system dis-
played on the select monitor?

Name and year of the system 
are displayed.

Go to step 7.

Go to step 6.

6

CHECK HARNESS CONNECTOR BETWEEN 
EACH CONTROL MODULE AND DATA LINK 
CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect ABSCM&H/U, cruise control 

module and immobilizer control module 
connectors.

3) Measure resistance between data link con-

nector and chassis ground.

Connector & terminal

(B40) No. 5 — Chassis ground:
(B40) No. 4 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 7.

Repair harness 
and connector 
between each 
control module 
and data link con-
nector.

7

CHECK OUTPUT SIGNAL FOR ABSCM&H/
U.
1) Turn ignition switch to ON.
2) Measure voltage between data link connec-

tor and chassis ground.

Connector & terminal

(B40) No. 5 (+) — Chassis ground (

−−−−

):

(B40) No. 4 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

1 V

Repair harness 
and connector 
between each 
control module 
and data link con-
nector.

Go to step 8.