Subaru Legacy III (2000-2003 year). Manual — part 720

ABS-98

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR

19

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 20.

Repair
ABSCM&H/U
ground harness.

20

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

There is no poor contact.

Go to step 21.

Repair connector.

21

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

Installed properly.

Go to step 22.

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

22

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 23.

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

23

CHECK SHIELD CIRCUIT.
1) Connect all connectors.
2) Measure resistance between shield con-

nector and chassis ground.

Connector & terminal

DTC 22 / LHD: (F45) No. 13 — Chassis
ground:
RHD: (F2) No. 14 — Chassis ground:
DTC 24 / LHD: (F45) No. 10 — Chassis
ground:
RHD: (F2) No. 17 — Chassis ground:

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

NOTE:

For the DTC 26 and 28:
Go to step 24.

0.5

Ω

Go to step 24.

Repair shield har-
ness.

24

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 25.

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

25

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

Other DTC is not indicated.

A temporary noise
interference.

Proceed with the
diagnosis corre-
sponding to the
DTC.

Step

Value

Yes

No

ABS-99

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR

MEMO:

ABS-100

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR

K: DTC 29 ABNORMAL ABS SENSOR SIGNAL ON ANY ONE OF FOUR SEN-

SOR

DIAGNOSIS:
• Faulty ABS sensor signal (noise, irregular signal, etc.)
• Faulty tone wheel
• Wheels turning freely for a long time
TROUBLE SYMPTOM:
• ABS does not operate.
WIRING DIAGRAM:

ABS00309

R73

R72

F49

FRONT

ABS

SENSOR LH

FRONT

ABS

SENSOR RH

ABS CONTROL MODULE AND HYDRAULIC CONTROL UNIT

F49

2

1

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

9

10

11

12

1

2

1

2

1

4

7

8

1

2

5

6

14

15

1

2

23

F55

R49

B15

B6

R73

R72

REAR

ABS

SENSOR LH

REAR

ABS

SENSOR RH

B6

B15

F55

15

16

14

12

13

17

8

9

13

11

12

10

F45

1

*

2

*

RHD

LHD

1

*

2

*

: LHD

RHD

: LHD

RHD B100

B62

F2

F45

1 2 3

4 5 6 7

8 9 10 11

12 13 14 15 16

1

2 3

4 5 6 7 8

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-101

ABS (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR

Step

Value

Yes

No

1

CHECK WHEELS FOR FREE TURNING.
Have wheels been turned freely for more than
one minute, such as when the vehicle is
jacked-up, under full-lock cornering or when
tire is not in contact with road surface.

Wheels have not turned freely. Go to step 2.

The ABS is nor-
mal. Erase the
diagnostic trouble
code.

NOTE:
When the wheels
turn freely for a
long time, such as
when the vehicle is
towed or jacked-
up, or when steer-
ing wheel is contin-
uously turned all
the way, this trou-
ble code may
sometimes occur.

2

CHECK TIRE SPECIFICATIONS.
Turn ignition switch to OFF.
Are the tire specifications correct?

Correct specification.

Go to step 3.

Replace tire.

3

CHECK WEAR OF TIRE.
Is the tire worn excessively?

Not worn excessively.

Go to step 4.

Replace tire.

4

CHECK TIRE PRESSURE.
Is the tire pressure correct?

Correct tire pressure.

Go to step 5.

Adjust tire pres-
sure.

5

CHECK INSTALLATION OF ABS SENSOR.
Are the ABS sensor installation bolts tightened
with the specified torque?

33

±

10 N·m (3.4

±

1.0 kgf-m,

25

±

7 ft-lb)

Go to step 6.

Tighten ABS sen-
sor installation
bolts securely.

6

CHECK ABS SENSOR GAP.
Measure tone wheel to ABS sensor piece gap
over entire perimeter of the wheel.
Is the measured value within the specified
range?

Front wheel 0.3 — 0.8 mm
(0.012 — 0.031 in) and Rear
wheel 0.44 — 0.94 mm
(0.0173 — 0.0370 in)

Go to step 7.

Adjust the gap.

NOTE:
Adjust the gap us-
ing spacer (Part
No. 26755AA000).
If spacers cannot
correct the gap, re-
place worn sensor
or worn tone
wheel.

7

PREPARE OSCILLOSCOPE.
Is an oscilloscope available?

Available.

Go to step 8.

Go to step 9.