Subaru Legacy III (2000-2003 year). Manual — part 711

ABS-62

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

U: DTC 41 ABNORMAL ABS CONTROL MODULE

DIAGNOSIS:
• Faulty ABSCM&H/U.
TROUBLE SYMPTOM:
• ABS does not operate.
WIRING DIAGRAM:

Step

Value

Yes

No

1

CHECK GROUND CIRCUIT OF ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABSCM&H/U.
3) Measure resistance between ABSCM&H/U

and chassis ground.

Connector & terminal

(F49) No. 23 — Chassis ground:

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

0.5

Ω

Go to step 2.

Repair
ABSCM&H/U
ground harness.

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

23

ABS CONTROL MODULE AND

HYDRAULIC CONTROL UNIT

F49

ABS00295

ABS-63

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

2

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between
battery, ignition switch and ABSCM&H/U?

There is no poor contact.

Go to step 3.

Repair connector.

3

CHECK SOURCES OF SIGNAL NOISE.
Is the car telephone or the wireless transmitter
properly installed?

Installed properly

Go to step 4.

Properly install the
car telephone or
the wireless trans-
mitter.

4

CHECK SOURCES OF SIGNAL NOISE.
Are noise sources (such as an antenna)
installed near the sensor harness?

Noise source is not installed
near the sensor harness.

Go to step 5.

Install the noise
sources apart from
the sensor har-
ness.

5

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 as in the current diagno-
sis still being output?

Same DTC is not indicated.

Go to step 6.

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

6

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-64

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

V: DTC 42 SOURCE VOLTAGE IS ABNORMAL.

DIAGNOSIS:
• Power source voltage of the ABSCM&H/U is low or high.
TROUBLE SYMPTOM:
• ABS does not operate.
WIRING DIAGRAM:

ABS00294

1

23

ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT

F49

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

BATTERY

NO

. 18 15A

SBF-4 50A

SBF-1 100A

GENERATOR

IGNITION
SWITCH

ABS-65

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

Step

Value

Yes

No

1

CHECK GENERATOR.
1) Start engine.
2) Idling after warm-up.
3) Measure voltage between generator B ter-

minal and chassis ground.

Terminal

Generator B terminal — Chassis
ground:

Is the measured value within the specified
range?

10 - 17 V

Go to step 2.

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

2

CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
Are the positive and negative battery terminals
tightly clamped?

Terminals are tightened
securely.

Go to step 3.

Tighten the clamp
of terminal.

3

CHECK INPUT VOLTAGE OF ABSCM&H/U.
1) Disconnect connector from ABSCM&H/U.
2) Run the engine at idle.
3) 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 - 17 V

Go to step 4.

Repair harness
connector
between battery,
ignition switch and
ABSCM&H/U.

4

CHECK GROUND CIRCUIT OF ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM&H/U

connector and chassis ground.

Connector & terminal

(F49) No. 23 — Chassis ground:

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

0.5

Ω

Go to step 5.

Repair
ABSCM&H/U
ground harness.

5

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between
generator, battery and ABSCM&H/U?

There is no poor contact.

Go to step 6.

Repair connector.

6

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 7.

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

7

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.