SUBARU LEGACY 1997 Service Repair Manual

B4M0523
2. V.RELAY OFF
—Valve relay OFF malfunction—
DIAGNOSIS:

Faulty valve relay

Faulty harness/connector

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS does not operate.

TCS does not operate.
1. Check resistance of valve relay.
<Ref. to 4-4b [T8I1].>
OK
Not OK
Replace valve relay.
2. Check contact point of valve relay.
<Ref. to 4-4b [T8I2].>
OK
Not OK
Replace valve relay.
3. Check input voltage of valve relay.
<Ref. to 4-4b [T8I4].>
OK
Not OK
Repair harness/connector.
4. Check harness between ABS/TCS control
module and valve relay.
<Ref. to 4-4b [T8I6].>
OK
Not OK
Repair harness/connector.
5. Check resistance of valve relay to ABS/TCS
control module side.
<Ref. to 4-4b [T8I7].>
OK
Not OK
Repair harness/connector.
Replace ABS/TCS control module.





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10. Diagnostic Chart with Select Monitor

B4M0524
X: TROUBLE CODE 52
1. MOTOR ON
—Motor relay ON malfunction—
DIAGNOSIS:

Faulty motor relay

Faulty motor

Faulty motor sensor

Faulty harness

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS does not operate.

TCS does not operate.
1. Check body short of harness.
<Ref. to 4-4b [T8J3].>
OK
Not OK
Repair harness.
2. Check motor operation.
<Ref. to 4-4b [T8J5].>
OK
Not OK
Replace motor relay.
3. Check body short of motor sensor.
<Ref. to 4-4b [T8J7].>
OK
Not OK
Replace hydraulic unit.
4. Check body short of motor sensor harness.
<Ref. to 4-4b [T8J9].>
OK
Not OK
Repair harness.
Replace ABS/TCS control module.




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10. Diagnostic Chart with Select Monitor

B4M0525
2. MOTOR OFF
—Motor relay OFF malfunction—
DIAGNOSIS:

Faulty motor relay

Faulty motor

Faulty motor sensor

Faulty harness/connector

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS and TCS do not operate.
1. Check resistance of motor relay.
<Ref. to 4-4b [T8J1].>
OK
Not OK
Replace motor relay.
2. Check input voltage of motor relay.
<Ref. to 4-4b [T8J2].>
OK
Not OK
Repair harness/connector.
3. Check harness between ABS/TCS control
module and motor relay.
<Ref. to 4-4b [T8J4].>
OK
Not OK
Repair harness/connector.
4. Check motor operation.
<Ref. to 4-4b [T8J5].>
OK
Not OK
Go to step 9.
5. Check resistance of motor sensor.
<Ref. to 4-4b [T8J6].>
OK
Not OK
Replace hydraulic unit.
6. Check body short of motor sensor.
<Ref. to 4-4b [T8J7].>
OK
Not OK
Replace hydraulic unit.
7. Check harness between ABS/TCS control
module and motor sensor.
<Ref. to 4-4b [T8J8].>
OK
Not OK
Repair harness/connector.
8. Check body short of motor sensor harness.
<Ref. to 4-4b [T8J9].>
OK
Not OK
Repair harness.
Replace ABS/TCS control module.








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10. Diagnostic Chart with Select Monitor

9. Check contact point of motor relay.
<Ref. to 4-4b [T8J10].>
OK
Not OK
Replace motor relay.
10. Check harness between motor and motor
relay.
<Ref. to 4-4b [T8J11].>
OK
Not OK
Repair harness/connector.
11. Check body short of motor harness.
<Ref. to 4-4b [T8J12].>
OK
Not OK
Repair harness.
12. Check ground circuit of motor.
<Ref. to 4-4b [T8J13].>
OK
Not OK
Repair harness/connector.
Replace hydraulic unit.
NOTE:
The check can also be made by analyzing the sensor out-
put signal with oscilloscope during the TCS sequence con-
trol operation. If the ECM female connector end gives cor-
rect value, skip steps 5 through 8.
If not, operate the TCS sequence control again and mea-
sure the value at motor sensor male connector end, with
the motor sensor connector disconnected. If the value is
OK, proceed with steps 7 through 8 above.




11 8
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10. Diagnostic Chart with Select Monitor

B4M0526
Y: TROUBLE CODE 54
1. B.SW HARD
—Break and short circuit at stroke sensor or its
wiring—
DIAGNOSIS:

Faulty stroke sensor

Faulty harness/connector

Faulty stop light switch

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS and TCS do not operate.
NOTE:
Operate the function F09 in select monitor TCS mode, and
read the sensor output step.
If system is normal, the output reading is 1 when brake
pedal is not depressed, and it changes from 2 to 3, 4 and
5 in accordance with the brake pedal depressing. If so, skip
check steps 1 through 5.
1. Check resistance of stroke sensor.
<Ref. to 4-4b [T8K2].>
OK
Not OK
Replace stroke sensor.
2. Check stroke sensor operation.
<Ref. to 4-4b [T8K3].>
OK
Not OK
Replace stroke sensor.
3. Check body short of stroke sensor.
<Ref. to 4-4b [T8K4].>
OK
Not OK
Replace stroke sensor.
4. Check harness between stroke sensor and
ABS/TCS control module.
<Ref. to 4-4b [T8K10].>
OK
Not OK
Repair harness/connector.
5. Check body short of stroke sensor harness.
<Ref. to 4-4b [T8K11].>
OK
Not OK
Repair harness.
Replace ABS/TCS control module.





11 9
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10. Diagnostic Chart with Select Monitor

B4M0527
2. B.SW SOFT (G)
—Irregular value in comparison stroke sensor and
vehicle acceleration comparison—
DIAGNOSIS:

Faulty stroke sensor

Faulty harness/connector

Faulty stop light switch

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS and TCS do not operate.
NOTE:
Operate the function F09 in select monitor TCS mode, and
read the sensor output step.
If system is normal, the output reading is 1 when brake
pedal is not depressed, and it changes from 2 to 3, 4 and
5 in accordance with the brake pedal depressing. If so, skip
check steps 2 through 4.
1. Check correct installation of stroke sensor.
<Ref. to 4-4b [T8K1].>
OK
Not OK
Repair stroke sensor.
2. Check resistance of stroke sensor.
<Ref. to 4-4b [T8K2].>
OK
Not OK
Replace stroke sensor.
3. Check stroke sensor operation.
<Ref. to 4-4b [T8K3].>
OK
Not OK
Replace stroke sensor.
4. Check harness between stroke sensor and
ABS/TCS control module.
<Ref. to 4-4b [T8K10].>
OK
Not OK
Repair harness/connector.
Replace ABS/TCS control module.




120
4-4bBRAKES
10. Diagnostic Chart with Select Monitor

B4M0528
3. B.SW SOFT (B)
—Irregular value in stroke sensor and brake light
switch comparison—
DIAGNOSIS:

Faulty stroke sensor

Faulty stop light switch

Faulty harness/connector

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

ABS and TCS do not operate.
NOTE:
Operate the function F09 in select monitor TCS mode, and
read the sensor output step.
If system is normal, the output reading is 1 when brake
pedal is not depressed, and it changes from 2 to 3, 4 and
5 in accordance with the brake pedal depressing. If so, skip
check steps 1 and 2 through 7.
Then, operate the function FA0 and check the stop and
brake switches by B1 LED ON/OFF. If system is normal,
LED comes on when depressing brake pedal, and goes off
when not depressing. If so, skip check steps 3 through 6.
1. Check resistance of stroke sensor.
<Ref. to 4-4b [T8K2].>
OK
Not OK
Replace stroke sensor.
2. Check stroke sensor operation.
<Ref. to 4-4b [T8K3].>
OK
Not OK
Replace stroke sensor.
3. Check contact point of stop light switch.
<Ref. to 4-4b [T8K5].>
OK
Not OK
Replace stroke sensor.
4. Check body short of stop light switch.
<Ref. to 4-4b [T8K6].>
OK
Not OK
Replace stroke sensor.
5. Check power supply of stop light switch.
<Ref. to 4-4b [T8K7].>
OK
Not OK
Repair harness/connector.
6. Check input voltage of ABS/TCS control mod-
ule.
<Ref. to 4-4b [T8K8].>
OK
Not OK
Repair harness/connector.
7. Check harness between stroke sensor and
ABS/TCS control module.
<Ref. to 4-4b [T8K10].>
OK
Not OK
Repair harness/connector.
Replace ABS/TCS control module.







121
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10. Diagnostic Chart with Select Monitor

B4M0529
4. B.SW SOFT (P)
—Comparison between stroke sensor and pump
output—
DIAGNOSIS:

Faulty stroke sensor

Faulty harness/connector

Faulty pump unit in hydraulic unit

Faulty stop light switch

Faulty ABS/TCS control module
NOTE:
Operate the function F09 in select monitor TCS mode, and
read the sensor output step.
If system is normal, the output reading is 1 when brake
pedal is not depressed, and it changes from 2 to 3, 4 and
5 in accordance with the brake pedal depressing. If so, skip
check steps 2 through 4.
1. Check correct installation of stroke sensor.
<Ref. to 4-4b [T8K1].>
OK
Not OK
Repair stroke sensor.
2. Check resistance of stroke sensor.
<Ref. to 4-4b [T8K2].>
OK
Not OK
Replace stroke sensor.
3. Check stroke sensor operation.
<Ref. to 4-4b [T8K3].>
OK
Not OK
Replace stroke sensor.
4. Check harness between stroke sensor and
ABS/TCS control module.
<Ref. to 4-4b [T8K10].>
OK
Not OK
Repair harness/connector.
5. Check pump unit operation.
<Ref. to 4-4b [T8K12].>
OK
Not OK
Replace hydraulic unit.
Replace ABS/TCS control module.





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10. Diagnostic Chart with Select Monitor

B4M0530
5. B.SW SOFT (O)
—Broken brake light switch—
DIAGNOSIS:

Faulty stop light switch

Faulty harness/connector

Faulty stroke sensor

Faulty ABS/TCS control module
TROUBLE SYMPTOM:

TCS does not operate.
NOTE:
Operate the function FA0 in select monitor TCS mode, and
check the stop and brake switches by B1 LED ON/OFF. If
system is normal, LED comes on when depressing brake
pedal, and goes off when not depressing. If so, skip check
steps 2 through 4.
1. Check correct installation of stroke sensor.
<Ref. to 4-4b [T8K1].>
OK
Not OK
Repair stroke sensor.
2. Check contact point of stop light switch.
<Ref. to 4-4b [T8K5].>
OK
Not OK
Replace stroke sensor.
3. Check input voltage of ABS/TCS control mod-
ule.
<Ref. to 4-4b [T8K8].>
OK
Not OK
Repair harness/connector.
4. Check stop light circuit.
<Ref. to 4-4b [T8K9].>
OK
Not OK
Repair harness/connector.
Replace stop light bulb and/or fuse.
Replace ABS/TCS control module.




123
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10. Diagnostic Chart with Select Monitor

B4M0531
Z: TROUBLE CODE 57
FLUID LEVEL SS
—Irregular signal from fluid level sensor—
DIAGNOSIS:

Faulty fluid level sensor circuit

Faulty harness/connector

Faulty ABS/TCS control module

Faulty generator
TROUBLE SYMPTOM:

ABS and TCS do not operate.
1. Check generator function.
<Ref. to 4-4b [T8L5].>
OK
Not OK
Repair generator.
2. Check input voltage of ABS/TCS control mod-
ule.
<Ref. to 4-4b [T8L6].>
OK
Not OK
Repair harness/connector.
Replace ABS/TCS control module.


124
4-4bBRAKES
10. Diagnostic Chart with Select Monitor