SUBARU LEGACY 1995 Service Repair Manual

B4M0711A
1. CHECK INPUT SIGNAL OF A.B.S. SENSOR TO
A.B.S. CONTROL MODULE SIDE.
1) Raise all four wheels of ground.
2) Turn ignition switch OFF.
3) Disconnect connector from A.B.S. control module.
4) Disconnect connector cover from connector. <Ref. to
4-4a [T7C2].>
5) Connect connector to A.B.S. control module.
6) Connect the oscilloscope to the A.B.S. control module
connector in accordance with the trouble code.
7) Turn ignition switch ON.
8) Rotate wheels and measure voltage at specified fre-
quency.
NOTE:
When this inspection is completed, the A.B.S. control mod-
ule sometimes memorizes the trouble code 29.
TROUBLE CODE / Connector & terminal:
22 / (P3) No. 23 (+)—No. 21 ()
24 / (P3) No. 22 (+)—No.4()
26 / (P3) No. 24 (+)—No. 26 ()
28 / (P3) No. 8 (+)—No.9()
Specified voltage: 0.12—1 V (When it is 20 Hz.)
B4M0248B
2. CHECK RESISTANCE OF A.B.S. SENSOR.
1) Turn ignition switch OFF.
2) Disconnect connector from A.B.S. sensor.
3) Measure resistance between A.B.S. sensor connector
terminals.
TROUBLE CODE / Connector & terminal:
22 / (B6) No. 1—No. 2
24 / (B15) No. 1—No. 2
26 / (P8) No. 1—No. 2
28 / (P9) No. 1—No. 2
Specified resistance: 0.8—1.2 kΩ
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7. Diagnostics Chart with Trouble Code

G4M0700
G4M0701
3. CHECK A.B.S. SENSOR MECHANICAL TROUBLE.
1) Dismount brake as outlined in manual to gain access to
A.B.S. sensor and tone wheel for inspection.
2) Check pole piece and tone wheel for accumulation of
foreign particles. If necessary, remove foreign particles and
clean.
3) Check tone wheel teeth for cracks for deformities. If
necessary, replace tone wheel (No. of teeth: 44) with a new
one.
4) Check tone wheel for looseness.
Tightening torque:
10—16 N⋅m (1.0—1.6 kg-m, 7—12 ft-lb)
5) Measure tone wheel-to-pole piece gap over entire
perimeter of the wheel.
SpecificationsFront wheel Rear wheel
0.9—1.4 mm
(0.035—0.055 in)0.7—1.2 mm
(0.028—0.047 in)
If measurements check out“Not OK”, adjust the gap using
spacers (Part No. 26755AA000). If spacers cannot correct
the gap, replace worn sensor or worn tone wheel.
6) Check hub runout.
Specifications 0.05 mm (0.0020 in)
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7. Diagnostics Chart with Trouble Code

E: TROUBLE CODE 29
—FAULTY TONE WHEEL, ETC.—
DIAGNOSIS:

Faulty tone wheel

Faulty A.B.S. control module
TROUBLE SYMPTOM:

A.B.S. does not operate.
NOTE:
When the wheels turn freely for a long time, such as when
the vehicle is towed or jacked-up, or when steering wheel
is continuously turned all the way, this trouble code may
sometimes occur.
Check tire specifications, tire wear and air
pressure.
<Ref. to 4-2 [S1A0].>
OK
Not OK
Replace tire.
1. Check input signal of A.B.S. sensor to
A.B.S. control module side.
Not OK
OK
Check contact of A.B.S. control module connector
terminal.
Not OK OK
Repair A.B.S. control module connector.
Replace A.B.S. control module.
2. Check resistance of A.B.S. sensor.
Not OK
OK
Repair harness/connector.
3. Check A.B.S. sensor mechanical trouble.
Not OK
OK
Replace A.B.S. sensor.
Repair mechanical trouble.
NOTE:
When checking A.B.S. sensor, carefully bend or swing con-
nector and harness to check for improper contact or open
circuits.






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7. Diagnostics Chart with Trouble Code

B4M0583
27
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7. Diagnostics Chart with Trouble Code

B4M0711A
1. CHECK INPUT SIGNAL OF A.B.S. SENSOR TO
A.B.S. CONTROL MODULE SIDE.
1) Raise all four wheels of ground.
2) Turn ignition switch OFF.
3) Disconnect connector from A.B.S. control module.
4) Disconnect connector cover from connector. <Ref. to
4-4a [T7C2].>
5) Connect connector to A.B.S. control module.
6) Connect the oscilloscope to the A.B.S. control module
connector in accordance with the trouble code.
7) Turn ignition switch ON.
8) Rotate wheels and measure voltage at specified fre-
quency.
NOTE:
When this inspection is completed, the A.B.S. control mod-
ule sometimes memorizes the trouble code 29.
Connector & terminal:
(P3) No. 23 (+)—No. 21 ()
(P3) No. 22 (+)—No.4()
(P3) No. 24 (+)—No. 26 ()
(P3) No. 8 (+)—No.9()
Specified voltage: 0.12—1 V (When it is 20 Hz.)
B4M0248B
2. CHECK RESISTANCE OF A.B.S. SENSOR.
1) Turn ignition switch OFF.
2) Disconnect connector from A.B.S. sensor.
3) Measure resistance between A.B.S. sensor connector
terminals.
Connector & terminal:
(B6) No. 1—No. 2
(B15) No. 1—No. 2
(P8) No. 1—No. 2
(P9) No. 1—No. 2
Specified resistance: 0.8—1.2 kΩ
28
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7. Diagnostics Chart with Trouble Code

G4M0700
G4M0701
3. CHECK A.B.S. SENSOR MECHANICAL TROUBLE.
1) Dismount brake as outlined in manual to gain access to
A.B.S. sensor and tone wheel for inspection.
2) Check pole piece and tone wheel for accumulation of
foreign particles. If necessary, remove foreign particles and
clean.
3) Check tone wheel teeth for cracks for deformities. If
necessary, replace tone wheel (No. of teeth: 44) with a new
one.
4) Check tone wheel for looseness.
Tightening torque:
10—16 N⋅m (1.0—1.6 kg-m, 7—12 ft-lb)
5) Measure tone wheel-to-pole piece gap over entire
perimeter of the wheel.
SpecificationsFront wheel Rear wheel
0.9—1.4 mm
(0.035—0.055 in)0.7—1.2 mm
(0.028—0.047 in)
If measurements check out“Not OK”, adjust the gap using
spacers (Part No. 26755AA000). If spacers cannot correct
the gap, replace worn sensor or worn tone wheel.
6) Check hub runout.
Specifications 0.05 mm (0.0020 in)
29
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7. Diagnostics Chart with Trouble Code

F: TROUBLE CODE 31, 33 AND 39
—FAULTY SOLENOID VALVE CIRCUIT(S) IN
HYDRAULIC CONTROL UNIT—
DIAGNOSIS:

Faulty harness/connector

Faulty solenoid valve in hydraulic control unit

Faulty A.B.S. control module
TROUBLE SYMPTOM:

A.B.S. does not operate.
1. Check resistance of solenoid valve
to A.B.S. control module side.
OK
Not OK
4. Check resistance of sole-
noid valve.
OK
Not OK
Replace hydraulic control unit.
Repair harness/connector.
2. Check voltage of solenoid valve to
A.B.S. control module side.
OK
Not OK
5. Check GND short of
hydraulic control unit.
OK
Not OK
Replace hydraulic control unit.
Repair harness/connector.
3. Check voltage of solenoid valve to
A.B.S. control module side.
OK
Not OK
6. Check battery short of
hydraulic control unit.
OK
Not OK
Replace hydraulic control unit.
Replace A.B.S. control module.Repair harness/connector.
B4M0712





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7. Diagnostics Chart with Trouble Code

B4M0256B
1. CHECK RESISTANCE OF SOLENOID VALVE TO
A.B.S. CONTROL MODULE SIDE.
1) Turn ignition switch OFF.
2) Disconnect connector from A.B.S. control module.
3) Measure resistance between A.B.S. control module
connector terminals.
TROUBLE CODE / Connector & terminal:
31 / (P3) No. 35—No. 32
33 / (P3) No. 2—No. 32
39 / (P3) No. 18—No. 32
Specified resistance: approx. 1Ω
B4M0257B
2. CHECK VOLTAGE OF SOLENOID VALVE TO A.B.S.
CONTROL MODULE SIDE.
1) Turn ignition switch OFF.
2) Disconnect valve relay from hydraulic control unit.
3) Turn ignition switch ON.
4) Measure voltage between A.B.S. control module con-
nector terminals.
TROUBLE CODE / Connector & terminal:
31 / (P3) No. 35—No. 20
33 / (P3) No. 2—No. 20
39 / (P3) No. 18—No. 20
Specified voltage: 10—12 V
B4M0257B
3. CHECK VOLTAGE OF SOLENOID VALVE TO A.B.S.
CONTROL MODULE SIDE.
1) Turn ignition switch OFF.
2) Disconnect combination meter fuse No. 15.
3) Turn ignition switch ON.
4) Measure voltage between A.B.S. control module con-
nector terminals.
TROUBLE CODE / Connector & terminal:
31 / (P3) No. 35—No. 20
33 / (P3) No. 2—No. 20
39 / (P3) No. 18—No. 20
Specified voltage: 0 V
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7. Diagnostics Chart with Trouble Code

B4M0259B
4. CHECK RESISTANCE OF SOLENOID VALVE.
1) Turn ignition switch OFF.
2) Disconnect connector from hydraulic control unit.
3) Measure resistance between hydraulic control unit ter-
minals.
TROUBLE CODE / Connector & terminal:
31 / to (F9) No. 4—No. 11
33 / to (F9) No. 3—No. 11
39 / to (F9) No. 1—No. 11
Specified resistance: approx. 1Ω
B4M0702A
5. CHECK GND SHORT OF HYDRAULIC CONTROL
UNIT.
1) Turn ignition switch OFF.
2) Disconnect connector from hydraulic control unit.
3) Measure resistance between hydraulic control unit ter-
minals.
Connector & terminal / Specified resistance:
(F9) No. 11—body/1MΩ
(F9) No. 11—No.8/1MΩ
B4M0259B
B4M0703A
6. CHECK BATTERY SHORT OF HYDRAULIC
CONTROL UNIT.
1) Turn ignition switch OFF.
2) Disconnect connector from hydraulic control unit.
3) Measure resistance between hydraulic control unit ter-
minals.
TROUBLE CODE / Connector & terminal:
31 / to (F9) No. 4—No. 11
33 / to (F9) No. 3—No. 11
39 / to (F9) No. 1—No. 11
Specified resistance: approx. 1Ω
4) Turn ignition ON.
5) Measure voltage between hydraulic control unit termi-
nals.
Connector & terminal / Specified voltage:
(F9) No. 11—body/0V
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7. Diagnostics Chart with Trouble Code

G: TROUBLE CODE 41
—FAULTY A.B.S. CONTROL MODULE—
DIAGNOSIS:

Faulty A.B.S. control module
TROUBLE SYMPTOM:

A.B.S. does not operate.
Replace A.B.S. control module.
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7. Diagnostics Chart with Trouble Code