1997 SUBARU LEGACY ignition

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
68
4-4bBRAKES
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
69
4-4bBRAKES
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
70
4-4bBRAKES
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.
71
4-4bBRAKES
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
74
4-4bBRAKES
8. Diagnostics Chart with Trouble Code

B4M0464A
3. CHECK STROKE SENSOR OPERATION.
1) Turn ignition switch OFF.
2) Disconnect stroke sensor connectors.
3) Remove stroke sensor.
4) Measure the stroke sensor resistance against the rod
stroke.
Terminal:
No. 3—No. 2
Stroke
Unit: mm (in)Specified
resistance
0—3.1±0.5 (0—0.122±0.020) 95—105Ω
3.1—5.5±0.5 (0.122—0.217±0.020) 190—210Ω
5.5—7.9±0.5 (0.217—0.311±0.020) 285—315Ω
7.9—10.3±0.5 (0.311—0.406±0.020) 380—420Ω
10.3—18±0.5 (0.406—0.709±0.020) 475—525Ω
NOTE:
Stroke = 0 when the stroke sensor rod is completely drawn
into the sensor unit.
B4M0465A
4. CHECK BODY SHORT OF STROKE SENSOR.
1) Turn ignition switch OFF.
2) Disconnect stroke sensor connectors.
3) Remove stroke sensor.
4) Measure resistance between stroke sensor terminal
and stroke sensor threads.
Terminal / Specified resistance:
No. 1—stroke sensor threads/ 1 MΩor more
No. 2—stroke sensor threads/ 1 MΩor more
No. 3—stroke sensor threads/ 1 MΩor more
B4M0466A
5. CHECK CONTACT POINT OF STOP LIGHT
SWITCH.
1) Turn ignition switch OFF.
2) Disconnect stroke sensor connectors.
3) Remove stroke sensor.
4) Measure resistance between stroke sensor terminals.
Terminal:
No. 2—No. 3
Stroke
Unit mm (in)Specified
resistance
0—2.2±1.0 (0—0.087±0.039) 1 MΩor more
2.2±1.0—18.0±0.5 (0.087±0.039—0.709±0.020) 1Ωor less
NOTE:
Stroke = 0 when the rod is completely drawn in.
75
4-4bBRAKES
8. Diagnostics Chart with Trouble Code

B4M0467A
6. CHECK BODY SHORT OF STOP LIGHT SWITCH.
1) Turn ignition switch OFF.
2) Disconnect stroke sensor connectors.
3) Remove stroke sensor.
4) Measure resistance between stroke sensor terminal
and stroke sensor threads.
Terminal / Specified resistance:
No. 2—stroke sensor threads/1MΩor more
No. 3—stroke sensor threads/1MΩor more
B4M0468A
7. CHECK POWER SUPPLY OF STOP LIGHT
SWITCH.
1) Turn ignition switch OFF.
2) Disconnect stroke sensor connector.
3) Measure voltage between stroke sensor connector and
body.
Connector & terminal / Specified voltage:
(B67) No. 3—body / 10—13 V
B4M0469A
8. CHECK INPUT VOLTAGE OF ABS/TCS CONTROL
MODULE.
1) Turn ignition switch OFF.
2) Install stroke sensor.
3) Connect stop light switch connector.
4) Disconnect ABS/TCS control module connector.
5) Measure voltage between ABS/TCS control module
connector and body.
Connector & terminal / Specified voltage:
(P7) No. 7—body / 10—13 V (With brake pedal
depressed)
(P7) No. 7—body/0V(Without brake pedal
depressed)
9. CHECK STOP LIGHT CIRCUIT.
1) Turn ignition switch OFF.
2) Install stroke sensor.
3) Connect stroke sensor connector.
4) Connect ABS/TCS control module connector.
5) Depress brake pedal and check that the stop light
comes on.
76
4-4bBRAKES
8. Diagnostics Chart with Trouble Code

B4M0470A
10. CHECK HARNESS BETWEEN STROKE SENSOR
AND ABS/TCS CONTROL MODULE.
1) Turn ignition switch OFF.
2) Install stroke sensor.
3) Connect stroke sensor connector.
4) Disconnect ABS/TCS control module connector.
5) Measure resistance between ABS/TCS control module
connector terminals.
Connector & terminal / Specified resistance:
(P7) No. 4—No. 14 / 570—630Ω
(P7) No. 5—No. 14 / 95—105Ω
NOTE:
Do not depress brake pedal.
B4M0471A
11. CHECK BODY SHORT OF STROKE SENSOR
HARNESS.
1) Turn ignition switch OFF.
2) Connect stroke sensor connector.
3) Disconnect ABS/TCS control module connector.
4) Measure resistance between ABS/TCS control module
connector and body.
Connector & terminal / Specified resistance:
(P7) No. 4—body/1MΩor more
(P7) No. 5—body/1MΩor more
(P7) No. 14—body/1MΩor more
12. CHECK PUMP UNIT OPERATION.
1) Turn ignition switch OFF.
2) Connect stroke sensor connector.
3) Connect stop light switch connector.
4) Connect ABS/TCS control module connector.
5) Operate the TCS sequence control and check that the
front brake fluid pressure increases and decreases cor-
rectly.
77
4-4bBRAKES
8. Diagnostics Chart with Trouble Code