SUBARU LEGACY 1997 Service Repair Manual

B4M1250A
10Z1
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect two connectors from AT control module.
3) Disconnect connector from ABSCM&H/U.
4) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 3 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step10Z2.
: Repair harness between AT control module and
ABSCM&H/U.
B4M1250A
10Z2
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 3 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step10Z3.
: Repair harness between AT control module and
ABSCM&H/U.
145
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1252A
10Z3
CHECK OPEN CIRCUIT OF HARNESS.
1) Turn ignition switch to OFF.
2) Connect all connectors to TCM.
3) Turn ignition switch to ON.
4) 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 13 V?
: Go to step10Z4.
: Repair harness/connector between TCM and
ABSCM&H/U.
10Z4CHECK POOR CONTACT IN CONNEC-
TORS.
Turn ignition switch to OFF.
: Is there poor contact in connectors between
AT control module and ABSCM&H/U? to FOREWORD [T3C1].>
: Repair connector.
: Go to step10Z5.
10Z5
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 step10Z6.
10Z6CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
146
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0968
AA: TROUBLE CODE 51 V. RELAY
—ABNORMAL VALVE RELAY—
DIAGNOSIS:

Faulty valve relay
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1253
147
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1254A
10AA1CHECK 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 step10AA2.
: Repair harness connector between battery and
ABSCM&H/U.
B4M1243A
10AA2CHECK 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 step10AA3.
: Repair ABSCM&H/U ground harness.
10AA3CHECK 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 step10AA4.
148
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

10AA4
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 step10AA5.
10AA5CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
149
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0802
AB: TROUBLE CODE 51 V. RELAY ON
—VALVE RELAY ON FAILURE—
DIAGNOSIS:

Faulty valve relay
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1253
150
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1272A
10AB1
CHECK VALVE RELAY IN ABSCM&H/U.
Measure resistance between ABSCM&H/U terminals.
Terminals
No. 23 (+)—No. 24 ():
: Is the resistance more than 1 MΩ?
: Go to step10AB2.
: Replace ABSCM&H/U.
10AB2CHECK 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 step10AB3.
10AB3
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 step10AB4.
10AB4CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
151
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0969
AC: TROUBLE CODE 52 M. RELAY OPEN
—OPEN CIRCUIT OF MOTOR RELAY—
DIAGNOSIS:

Faulty motor

Faulty motor relay

Faulty harness connector
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1255
152
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1256A
10AC1CHECK 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 13 V?
: Go to step10AC2.
: Repair harness/connector between battery and
ABSCM&H/U and check fuse SBF6.
B4M1257A
10AC2
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 step10AC3.
: Repair ABSCM&H/U ground harness.
10AC3
CHECK MOTOR OPERATION.
Operate the check sequence.
NOTE:
Use the diagnosis connector to operate the sequence con-
trol.
: Can motor revolution noise (buzz) be heard
when carrying out the check sequence?
: Go to step10AC4.
: Replace ABSCM&H/U.
153
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

10AC4CHECK POOR CONTACT IN CONNEC-
TORS.
Turn ignition switch to OFF.
: Is there poor contact in connector between
hydraclic unit, relay box and ABSCM&H/U?

: Repair connector.
: Go to step10AC5.
10AC5
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 step10AC6.
10AC6CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
154
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor