1997 SUBARU LEGACY ABS

B4M1252A
8U7
CHECK OPEN CIRCUIT OF HARNESS.
Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 3 (+)—Chassis ground ():
(F49) No. 31 (+)—Chassis ground ():
: Is the voltage between 10 V and 15 V?
: Go to step8U8.
: Repair harness/connector between TCM and
ABSCM&H/U.
8U8CHECK POOR CONTACT IN CONNEC-
TORS.
: Is there poor contact in connectors between
TCM and ABSCM&H/U? WORD [T3C1].>
: Repair connector.
: Go to step8U9.
8U9
CHECK ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Connect all connectors.
3) Erase the memory.
4) Perform inspection mode.
5) Read out the trouble code.
: Is the same trouble code as in the current
diagnosis still being output?
: Replace ABSCM&H/U.
: Go to step8U10.
8U10CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
62
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

V: TROUBLE CODE 51
—ABNORMAL VALVE RELAY—
DIAGNOSIS:

Faulty valve relay
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1253
63
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M1254A
8V1CHECK INPUT VOLTAGE OF
ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABSCM&H/U.
3) Run the engine at idle.
4) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 1 (+)—Chassis ground ():
(F49) No. 24 (+)—Chassis ground ():
: Is the voltage between 10 V and 15 V?
: Go to step8V2.
: Repair harness connector between battery and
ABSCM&H/U.
B4M1243A
8V2CHECK GROUND CIRCUIT OF
ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 23—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step8V3.
: Repair ABSCM&H/U ground harness.
B4M1272A
8V3
CHECK VALVE RELAY IN ABSCM&H/U.
Measure resistance between ABSCM&H/U and terminals.
Terminals
No. 23 (+)—No. 24 ():
: Is the resistance more than 1 MΩ?
: Go to step8V4.
: Replace ABSCM&H/U.
64
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

8V4CHECK POOR CONTACT IN CONNEC-
TORS.
: Is there poor contact in connectors between
generator, battery and ABSCM&H/U? to FOREWORD [T3C1].>
: Repair connector.
: Go to step8V5.
8V5
CHECK ABSCM&H/U.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the trouble code.
: Is the same trouble code as in the current
diagnosis still being output?
: Replace ABSCM&H/U.
: Go to step8V6.
8V6CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
65
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

W: TROUBLE CODE 52
—ABNORMAL MOTOR AND/OR MOTOR
RELAY—
DIAGNOSIS:

Faulty motor

Faulty motor relay

Faulty harness connector
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1255
66
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M1256A
8W1CHECK INPUT VOLTAGE OF
ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABSCM&H/U.
3) Turn ignition switch to ON.
4) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 25 (+)—Chassis ground ():
: Is the voltage between 10 V and 15 V?
: Go to step8W2.
: Repair harness/connector between battery and
ABSCM&H/U and check fuse SBF6.
B4M1257A
8W2
CHECK GROUND CIRCUIT OF MOTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 26—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step8W3.
: Repair ABSCM&H/U ground harness.
67
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M1234A
8W3CHECK INPUT VOLTAGE OF
ABSCM&H/U.
1) Run the engine at idle.
2) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 1 (+)—Chassis ground ():
: Is the voltage between 10 V and 15 V?
: Go to step8W4.
: Repair harness connector between battery, igni-
tion switch and ABSCM&H/U.
B4M1243A
8W4CHECK GROUND CIRCUIT OF
ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 23—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step8W5.
: Repair ABSCM&H/U ground harness.
8W5
CHECK MOTOR OPERATION.
Operate the sequence control.
NOTE:
Use the diagnosis connector to operate the sequence con-
trol.
: Can motor revolution noise (buzz) be heard
when carrying out the sequence control?
: Go to step8W6.
: Replace ABSCM&H/U.
68
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

8W6CHECK POOR CONTACT IN CONNEC-
TORS.
Turn ignition switch to OFF.
: Is there poor contact in connector between
generator, battery and ABSCM&H/U? to FOREWORD [T3C1].>
: Repair connector.
: Go to step8W7.
8W7
CHECK ABSCM&H/U.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the trouble code.
: Is the same trouble code as in the current
diagnosis still being output?
: Replace ABSCM&H/U.
: Go to step8W8.
8W8CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
69
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light