1997 SUBARU LEGACY ignition

B4M0430
7B4
CHECK GENERATOR.
1) Start the engine.
2) Idle the engine.
3) Measure voltage between generator and chassis
ground.
Terminal
Generator B terminal (+)—Chassis ground ():
: Is the voltage between 10 and 15 V?
: Go to step7B5.
: Repair generator.
7B5
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Is there poor contact at battery terminal?
: Repair battery terminal.
: Go to step7B6.
B4M1234A
7B6
CHECK POWER SUPPLY OF ABSCM.
1) Disconnect connector from ABSCM&H/U.
2) Start engine.
3) Idle the engine.
4) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 1 (+)—Chassis ground ():
: Is the voltage between 10 and 15 V?
: Go to step7B7.
: Repair ABSCM&H/U power supply circuit.
7B7
CHECK WIRING HARNESS.
1) Disconnect connector (F2) from connector (B100).
2) Turn ignition switch to ON.
: Does the ABS warning light remain off?
: Go to step7B8.
: Repair front wiring harness.
B4M1235A
7B8
CHECK PROJECTION AT ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Check for broken projection at the ABSCM&H/U termi-
nal.
: Are the projection broken?
: Go to step7B9.
: Replace ABSCM&H/U.
23
4-4dBRAKES [ABS 5.3i TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0800A
7C1
CHECK DIAGNOSIS TERMINAL.
Measure resistance between diagnosis terminals (B81)
and chassis ground.
Terminals
Diagnosis terminal (A)—Chassis ground:
Diagnosis terminal (B)—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step7C2.
: Repair diagnosis terminal harness.
B4M1233A
7C2
CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal to diagnosis connector
(B82) No. 6.
3) Disconnect connector from ABSCM&H/U.
4) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 4—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step7C3.
: Repair harness connector between ABSCM&H/U
and diagnosis connector.
7C3CHECK POOR CONTACT IN ABSCM&H/U
CONNECTOR.
: Is there poor contact in ABSCM&H/U con-
nector?
: Repair connector.
: Replace ABSCM&H/U.
26
4-4dBRAKES [ABS 5.3i TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0806E
B4M1036C
8E1
CHECK ABS SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABS sensor.
3) Measure resistance of ABS sensor connector terminals.
Terminal
Front RH No. 1—No. 2:
Front LH No. 1—No. 2:
Rear RH No. 1—No. 2:
Rear LH No. 1—No. 2:
: Is the resistance between 0.8 and 1.2 kΩ?
: Go to step8E2.
: Replace ABS sensor.
B4M0807E
B4M1037C
8E2CHECK BATTERY SHORT OF ABS SEN-
SOR.
1) Disconnect connector from ABSCM&H/U.
2) Measure voltage between ABS sensor and chassis
ground.
Terminal
Front RH No. 1 (+)—Chassis ground ():
Front LH No. 1 (+)—Chassis ground ():
Rear RH No. 1 (+)—Chassis ground ():
Rear LH No. 1 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step8E3.
: Replace ABS sensor.
29
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M0807E
B4M1037C
8E3CHECK BATTERY SHORT OF ABS SEN-
SOR.
1) Turn ignition switch to ON.
2) Measure voltage between ABS sensor and chassis
ground.
Terminal
Front RH No. 1 (+)—Chassis ground ():
Front LH No. 1 (+)—Chassis ground ():
Rear RH No. 1 (+)—Chassis ground ():
Rear LH No. 1 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step8E4.
: Replace ABS sensor.
B4M1239A
8E4CHECK HARNESS/CONNECTOR
BETWEEN ABSCM&H/U AND ABS SEN-
SOR.
1) Turn ignition switch to OFF.
2) Connect connector to ABS sensor.
3) Measure resistance between ABSCM&H/U connector
terminals.
Connector & terminal
Trouble code 21 / (F49) No. 11—No. 12:
Trouble code 23 / (F49) No. 9—No. 10:
Trouble code 25 / (F49) No. 14—No. 15:
Trouble code 27 / (F49) No. 7—No. 8:
: Is the resistance between 0.8 and 1.2 kΩ?
: Go to step8E5.
: Repair harness/connector between ABSCM&H/U
and ABS sensor.
30
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M1240A
8E5
CHECK BATTERY SHORT OF HARNESS.
Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
Trouble code 21 / (F49) No. 11 (+)—Chassis ground
():
Trouble code 23 / (F49) No. 9 (+)—Chassis ground
():
Trouble code 25 / (F49) No. 14 (+)—Chassis ground
():
Trouble code 27 / (F49) No. 7 (+)—Chassis ground
():
: Is the voltage less than 1 V?
: Go to step8E6.
: Repair harness between ABSCM&H/U and ABS
sensor.
B4M1240A
8E6
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
Trouble code 21 / (F49) No. 11 (+)—Chassis ground
():
Trouble code 23 / (F49) No. 9 (+)—Chassis ground
():
Trouble code 25 / (F49) No. 14 (+)—Chassis ground
():
Trouble code 27 / (F49) No. 7 (+)—Chassis ground
():
: Is the voltage less than 1 V?
: Go to step8E7.
: Repair harness between ABSCM&H/U and ABS
sensor.
8E7CHECK INSTALLATION OF ABS SEN-
SOR.
Tightening torque:
32±10 N⋅m (3.3±1.0 kg-m, 24±7 ft-lb)
: Are the ABS sensor installation bolts tight-
ened securely?
: Go to step8E8.
: Tighten ABS sensor installation bolts securely.
31
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M0818E
B4M1042C
8E11CHECK GROUND SHORT OF ABS SEN-
SOR.
1) Turn ignition switch to ON.
2) Measure resistance between ABS sensor and chassis
ground.
Terminal
Front RH No. 1—Chassis ground:
Front LH No. 1—Chassis ground:
Rear RH No. 1—Chassis ground:
Rear LH No. 1—Chassis ground:
: Is the resistance more than 1 MΩ?
: Go to step8E12.
: Replace ABS sensor and ABSCM&H/U.
B4M1241A
8E12
CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Connect connector to ABS sensor.
3) Measure resistance between ABSCM&H/U connector
terminal and chassis ground.
Connector & terminal
Trouble code 21 / (F49) No. 11—Chassis ground:
Trouble code 23 / (F49) No. 9—Chassis ground:
Trouble code 25 / (F49) No. 14—Chassis ground:
Trouble code 27 / (F49) No. 7—Chassis ground:
: Is the resistance more than 1 MΩ?
: Go to step8E13.
: Repair harness between ABSCM&H/U and ABS
sensor.
Replace ABSCM&H/U.
8E13CHECK POOR CONTACT IN CONNEC-
TORS.
: Is there poor contact in connectors between
ABSCM&H/U and ABS sensor? FOREWORD [T3C1].>
: Repair connector.
: Go to step8E14.
33
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

8I5
CHECK ABS SENSOR SIGNAL.
1) Raise all four wheels of ground.
2) Turn ignition switch OFF.
3) Connect the oscilloscope to the connector (F1) or con-
nector (B100).
4) Turn ignition switch ON.
B4M1242A
5) Rotate wheels and measure voltage at specified fre-
quency.
NOTE:
When this inspection is completed, the ABS control mod-
ule sometimes stores the trouble code 29.
Connector & terminal
Trouble code 22 / (B100) No. 12 (+)—No. 13 ():
Trouble code 24 / (B100) No. 3 (+)—No.4():
Trouble code 26 / (F1) No. 4 (+)—No.5():
Trouble code 28 / (F1) No. 1 (+)—No.2():
Specified voltage: 0.12—1 V (When it is 20 Hz.)
: Is oscilloscope pattern smooth, as shown in
figure?
: Go to step8I9.
: Go to step8I6.
8I6CHECK CONTAMINATION OF ABS SEN-
SOR OR TONE WHEEL.
Remove disc rotor or drum from hub in accordance with
trouble code.
: Is the ABS sensor pole piece or the tone
wheel contaminated by dirt or other foreign
matter?
: Thoroughly remove dirt or other foreign matter.
: Go to step8I7.
8I7CHECK DAMAGE OF ABS SENSOR OR
TONE WHEEL.
: Are there broken or damaged in the ABS
sensor pole piece or the tone wheel?
: Replace ABS sensor or tone wheel.
: Go to step8I8.
37
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

8I8
CHECK HUB RUNOUT.
Measure hub runout.
: Is the runout less than 0.05 mm (0.0020 in)?
: Go to step8I9.
: Repair hub.
B4M0806E
B4M1036C
8I9
CHECK RESISTANCE OF ABS SENSOR.
1) Turn ignition switch OFF.
2) Disconnect connector from ABS sensor.
3) Measure resistance between ABS sensor connector ter-
minals.
Terminal
Front RH No. 1—No. 2:
Front LH No. 1—No. 2:
Rear RH No. 1—No. 2:
Rear LH No. 1—No. 2:
: Is the resistance between 0.8 and 1.2 kΩ?
: Go to step8I10.
: Replace ABS sensor.
B4M0818E
B4M1042C
8I10CHECK GROUND SHORT OF ABS SEN-
SOR.
Measure resistance between ABS sensor and chassis
ground.
Terminal
Front RH No. 1—Chassis ground:
Front LH No. 1—Chassis ground:
Rear RH No. 1—Chassis ground:
Rear LH No. 1—Chassis ground:
: Is the resistance more than 1 MΩ?
: Go to step8I11.
: Replace ABS sensor.
38
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light