SUBARU LEGACY 1997 Service Repair Manual

B4M0446A
6. CHECK HARNESS BETWEEN ABS/TCS CONTROL
MODULE AND VALVE RELAY.
1) Turn ignition switch OFF.
2) Disconnect valve relay.
3) Disconnect ABS/TCS control module.
4) Measure resistance between ABS/TCS control module
connector and body.
Connector & terminal / Specified resistance:
(P6) No. 6—body/1MΩor more
5) Connect valve relay.
6) Measure resistance between ABS/TCS control module
connector and body.
Connector & terminal / Specified resistance:
(P6) No. 6—body / 1Ωor less
B4M0447A
7. CHECK RESISTANCE OF VALVE RELAY TO ABS/
TCS CONTROL MODULE SIDE.
1) Turn ignition switch OFF.
2) Connect valve relay.
3) Disconnect ABS/TCS control module.
4) Measure resistance between ABS/TCS control module
connector terminals.
Connector & terminal / Specified resistance:
(P5) No. 1—(P6) No. 1 / 90±10Ω
B4M0729A
8. CHECK BODY SHORT OF HARNESS.
1) Turn ignition switch OFF.
2) Connect valve relay.
3) Disconnect ABS/TCS control module.
4) Turn ignition switch ON.
5) Measure voltage between ABS/TCS control module
connector and body.
Connector & terminal / Specified voltage:
(P6) No. 1—body / 10—13 V
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8. Diagnostics Chart with Trouble Code

J: TROUBLE CODE 52
—FAULTY MOTOR, MOTOR SENSOR AND/
OR MOTOR RELAY—
DIAGNOSIS:

Faulty motor relay

Faulty motor

Faulty motor sensor

Faulty harness/connector

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS does not operate.

TCS does not operate.
1. Check resistance of motor relay.
OK
Not OK
Replace motor relay.
2. Check input voltage of motor relay.
OK
Not OK
Repair harness/connector.
3. Check body short of harness.
OK
Not OK
Repair harness.
4. Check harness between ABS/TCS control
module and motor relay.
OK
Not OK
Repair harness/connector.
5. Check motor operation.
OK
Not OK
Go to step 10.
6. Check resistance of motor sensor.
OK
Not OK
Replace hydraulic unit.
7. Check body short of motor sensor.
OK
Not OK
Replace hydraulic unit.
8. Check harness between ABS/TCS control
module and motor sensor.
OK
Not OK
Repair harness/connector.
9. Check body short of motor sensor harness.
OK
Not OK
Repair harness.
Replace ABS/TCS control module.









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8. Diagnostics Chart with Trouble Code

10. Check contact point of motor relay.
OK
Replace motor relay.
11. Check harness between motor and motor
relay.
OK
Repair harness/connector.
12. Check body short of motor harness.
OK
Repair harness.
13. Check ground circuit of motor.
OK
Repair harness/connector.
Replace hydraulic unit.
B4M0741




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8. Diagnostics Chart with Trouble Code

B4M0730A
1. CHECK RESISTANCE OF MOTOR RELAY.
1) Turn ignition switch OFF.
2) Remove motor relay.
3) Measure resistance between motor relay terminals.
Terminal / Specified resistance:
No. a—b/57Ω
NOTE:
Apply + to b terminal.
Apply to a terminal.
B4M0451A
2. CHECK INPUT VOLTAGE OF MOTOR RELAY.
1) Turn ignition switch OFF.
2) Disconnect motor relay.
3) Measure voltage between motor relay connector and
body.
Connector & terminal / Specified voltage:
(F10) No. 1—body / 10—13 V
(F10) No. 3—body/0V
4) Turn ignition switch ON.
5) Measure voltage between motor relay connector and
body.
Connector & terminal / Specified voltage:
(F10) No. 1—body / 10—13 V
(F10) No. 3—body / 10—13 V (In 1 second after
turning ignition key ON.)
B4M0452A
3. CHECK BODY SHORT OF HARNESS.
1) Turn ignition switch OFF.
2) Disconnect motor relay.
3) Disconnect ABS/TCS control module.
4) Measure resistance between ABS/TCS control module
connector and body.
Connector & terminal / Specified resistance:
(P6) No. 9—body/1MΩor more
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8. Diagnostics Chart with Trouble Code

B4M0731A
4. CHECK HARNESS BETWEEN ABS/TCS CONTROL
MODULE AND MOTOR RELAY.
1) Turn ignition switch OFF.
2) Connect motor relay.
3) Disconnect ABS/TCS control module.
4) Measure resistance between ABS/TCS control module
connector and body.
NOTE:
Apply + to GND.
Applyto (P6) No. 9.
Connector & terminal / Specified resistance:
(P6) No. 9—body / 57±6Ω
5. CHECK MOTOR OPERATION.
1) Connect motor relay.
2) Connect ABS/TCS control module.
3) Operate the TCS sequence check.

4) By the whirring sound check that the motor rotates.
B4M0454A
6. CHECK RESISTANCE OF MOTOR SENSOR.
1) Turn ignition switch OFF.
2) Disconnect motor sensor connector.
3) Measure resistance between motor sensor connector
terminals.
Connector & terminal / Specified resistance:
(F14) No. 1—No.2/72—98Ω
B4M0455A
7. CHECK BODY SHORT OF MOTOR SENSOR.
1) Turn ignition switch OFF.
2) Disconnect motor sensor connector.
3) Measure resistance between motor sensor connector
and body.
Connector & terminal / Specified resistance:
(F14) No. 1—body/1MΩor more
(F14) No. 2—body/1MΩor more
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8. Diagnostics Chart with Trouble Code

B4M0456A
8. CHECK HARNESS BETWEEN ABS/TCS CONTROL
MODULE AND MOTOR SENSOR.
1) Turn ignition switch OFF.
2) Connect motor sensor connector.
3) Disconnect ABS/TCS control module.
4) Measure resistance between ABS/TCS control module
connector terminals.
Connector & terminal / Specified resistance:
(P7) No. 3—No. 13 / 72—98Ω
B4M0457A
9. CHECK BODY SHORT OF MOTOR SENSOR
HARNESS.
1) Turn ignition switch OFF.
2) Connect motor sensor connector.
3) Disconnect ABS/TCS control module.
4) Measure resistance between ABS/TCS control module
and body.
Connector & terminal / Specified resistance:
(P7) No. 3—body/1MΩor more
(P7) No. 13—body/1MΩor more
B4M0458A
10. CHECK CONTACT POINT OF MOTOR RELAY.
1) Connect motor relay.
2) Connect ABS/TCS control module.
3) Operate the TCS sequence check. [W20F0].>
4) Measure voltage between motor relay connector and
body.
Connector & terminal / Specified voltage:
(F10) No. 4—body / 10—14 V (While TCS oper-
ating indicator light is ON.)
B4M0459A
11. CHECK HARNESS BETWEEN MOTOR AND
MOTOR RELAY.
1) Turn ignition switch OFF.
2) Disconnect motor relay.
3) Disconnect motor connector.
4) Measure resistance between motor relay connector and
motor connector.
Connector & terminal / Specified resistance:
(F13) No. 2—(F10) No.4/1Ωor less
B4M0460A
12. CHECK BODY SHORT OF MOTOR HARNESS.
1) Turn ignition switch OFF.
2) Disconnect motor relay.
3) Disconnect motor connector.
4) Measure resistance between motor connector and
body.
Connector & terminal / Specified resistance:
(F13) No. 2—body/1MΩor more
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8. Diagnostics Chart with Trouble Code

B4M0461A
13. CHECK GROUND CIRCUIT OF MOTOR.
1) Turn ignition switch OFF.
2) Disconnect motor connector.
3) Measure resistance between motor connector and
body.
Connector & terminal / Specified resistance:
(F13) No. 1—body / 1Ωor less
NOTE:
The check can also be made by analyzing the waves of the
motor sensor output signal with oscilloscope during the
TCS sequence control operation. If the ECM female con-
nector end gives correct value, skip steps 6 through 9
above.
If not, operate the TCS sequence control again and mea-
sure the value at motor sensor male connector end with the
motor sensor connector removed. If the value is OK, pro-
ceed with steps 8 and 9 above.
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8. Diagnostics Chart with Trouble Code

K: TROUBLE CODE 54
—FAULTY STROKE SENSOR AND/OR STOP
LIGHT SWITCH—
DIAGNOSIS:

Faulty stroke sensor

Faulty stop light switch

Faulty pump unit in hydraulic unit

Faulty ABS/TCS control module

Faulty harness/connector
TROUBLE SYMPTOM:

ABS and TCS do not operate.

No kick-back ocuurs while ABS is functioning.

Only when the stop light switch circuit is broken, the ABS
functions while TCS does not. (TCS warning light only illu-
minates.)
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8. Diagnostics Chart with Trouble Code

1. Check correct installation of stroke sensor.
OK
Not OK
Repair stroke sensor.
2. Check resistance of stroke sensor.
OK
Not OK
Replace stroke sensor.
3. Check stroke sensor operation.
OK
Not OK
Replace stroke sensor.
4. Check body short of stroke sensor.
OK
Not OK
Replace stroke sensor.
5. Check contact point of stop light switch.
OK
Not OK
Replace stroke sensor.
6. Check body short of stop light switch.
OK
Not OK
Replace stroke sensor.
7. Check power supply of stop light switch.
OK
Not OK
Repair harness/connector.
8. Check input voltage of ABS/TCS control mod-
ule.
OK
Not OK
Repair harness/connector.
9. Check stop light circuit.
OK
Not OK
Repair harness/connector.
Replace stop light bulb and/or fuse.
10. Check harness between stroke sensor and
ABS/TCS control module.
OK
Not OK
Repair harness/connector.
11. Check body short of stroke sensor harness.
OK
Not OK
Repair harness.
12. Check pump unit operation.
OK
Not OK
Replace hydraulic unit.
Replace ABS/TCS control module.












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8. Diagnostics Chart with Trouble Code

B4M0732
1. CHECK CORRECT INSTALLATION OF STROKE
SENSOR.
1) Check that the stroke sensor is firmly installed without
play.
2) Check that the stop lamp does not remain illuminated.
B4M0463A
2. CHECK RESISTANCE OF STROKE SENSOR.
1) Turn ignition switch OFF.
2) Disconnect stroke sensor connectors.
3) Remove stroke sensor.
4) Measure resistance between stroke sensor terminals.
Terminal / Specified resistance:
No. 1—No. 3 / 570—630Ω
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8. Diagnostics Chart with Trouble Code