1996 SUBARU LEGACY Chassis

B4M0846A
8I2
CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect two connectors from AT control module.
3) Disconnect connector from ABSCM.
4) Measure resistance between ABSCM connector and
chassis ground.
: Connector & terminal
(F49) No. 12—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8I3.
: Repair harness between AT control module and
ABSCM.
B4M0847A
8I3
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 12 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between AT control module and
ABSCM.
3) Turn ignition switch to OFF.
4) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 12 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8I4.
: Repair harness between AT control module and
ABSCM.
68
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0848B
8I4
CHECK AT CONTROL MODULE.
1) Connect all connectors to AT control module.
2) Turn ignition switch to ON.
3) Measure voltage between AT control module connector
terminals.
: Connector & terminal
(B55) No. 1 (+)—(B56) No. 5 ()
Is voltage 10—13 V?
: Go to step8I5.
: Go to next step.
B4M0849B
4) Measure voltage between AT control module connector
and chassis ground.
: Connector & terminal
(B54) No. 6 (+)—Chassis ground ()
(B55) No. 1 (+)—Chassis ground ()
Is voltage 10—13 V?
: Replace AT control module.
: Repair harness connector between battery, igni-
tion switch and AT control module.
B4M0844A
8I5
CHECK OPEN CIRCUIT OF HARNESS.
Measure voltage between ABSCM connector and chassis
ground.
: Connector & terminal
(F49) No. 12 (+)—Chassis ground ()
(F49) No. 39 (+)—Chassis ground ()
Is voltage 10—13 V?
: Go to step8I6.
: Repair harness connector between AT control
module and ABSCM.
69
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0852B
8J2
CHECK GROUND SHORT OF G SENSOR.
Measure resistance between G sensor and bracket.
: Connector & terminal
To (P11) No. 3—Bracket
Is resistance more than 1 MΩ?
: Go to step8J3.
: Replace G sensor.
B4M0853A
8J3CHECK SHORT OF HARNESS BETWEEN
ABSCM AND G SENSOR.
1) Disconnect connector from ABSCM.
2) Measure resistance between ABSCM connector termi-
nals.
: Connector & terminal
(F49) No. 45—No. 8
Is resistance more than 1 MΩ?
: Go to step8J4.
: Repair harness between ABSCM and G sensor.
B4M0854A
8J4
CHECK GROUND SHORT OF HARNESS.
Measure resistance between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 8—Chassis ground
(F49) No. 45—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8J5.
: Repair harness between ABSCM and G sensor.
73
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0855A
8J5
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 8 (+)—Chassis ground ()
(F49) No. 45 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between ABSCM and G sensor.
3) Turn ignition switch to OFF.
4) Measure voltage between ABSCM and chassis ground.
: Connector & terminal
(F49) No. 8 (+)—Chassis ground ()
(F49) No. 45 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8J6.
: Repair harness between ABSCM and chassis
ground.
8J6CHECK POOR CONTACT IN CONNEC-
TOR BETWEEN ABSCM AND G SENSOR.
: Is there poor contact in connectors between
ABSCM and G sensor?
: Repair connector.
: Go to step8J7.
8J7
CHECK ABSCM.
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.
: Go to next.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
74
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0862B
8K4CHECK POWER SUPPLY VOLTAGE AT
VALVE RELAY CONTACT POINT.
1) Disconnect connector (F8) from relay box.
2) Measure voltage between relay box connector and
chassis ground.
: Connector & terminal
(F8) No. 1 (+)—Chassis ground ()
Is voltage 10—13 V?
: Go to step8K5.
: Repair harness connector between battery and
relay box. Check fuse No. 19.
B4M0863B
8K5CHECK GROUND CIRCUIT OF RELAY
BOX.
1) Disconnect connector (F50) from relay box.
2) Measure resistance between relay box connector and
chassis ground.
: Connector & terminal
(F50) No. 3—Chassis ground
Is resistance less than 0.5Ω?
: Go to step8K6.
: Repair relay box ground harness.
79
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0864
8K6CHECK BROKEN WIRE AND GROUND
SHORT IN POWER SUPPLY CIRCUIT OF
RELAY BOX.
1) Disconnect connector (ABS1) from hydraulic unit.
2) Connect connector (F8) to relay box.
3) Measure voltage of relay box.
: Connector & terminal
Valve relay installing point No. 87—Chas-
sis ground
Is voltage 10—13 V?
: Go to step8K7.
: Replace relay box. Check fuse No. 19.
B4M0865A
8K7CHECK BROKEN WIRE IN CONTACT
POINT CIRCUIT OF RELAY BOX.
Measure resistance between hydraulic unit connector and
valve relay installing point.
: Connector & terminal
(ABS1) No. 2—Valve relay installing point
No. 30
Is resistance less than 0.5Ω?
: Go to step8K8.
: Replace relay box.
B4M0866A
8K8CHECK GROUND SHORT IN CONTACT
POINT CIRCUIT OF RELAY BOX.
Measure resistance between hydraulic unit connector and
chassis ground.
: Connector & terminal
(ABS1) No. 2—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8K9.
: Replace relay box. Check fuse SBF6.
80
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0867A
8K9CHECK BATTERY SHORT IN CONTACT
POINT CIRCUIT OF RELAY BOX.
1) Disconnect connector from ABSCM.
2) Turn ignition switch to ON.
3) Measure voltage between hydraulic unit connector and
chassis ground.
: Connector & terminal
(ABS1) No. 2 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace relay box. Check fuse No. 19 and SBF6.
4) Turn ignition switch to OFF.
5) Measure voltage between hydraulic unit connector and
chassis ground.
: Connector & terminal
(ABS1) No. 2 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8K10.
: Replace relay box. Check fuse No. 19 and SBF6.
B4M0868B
8K10
CHECK DIODE OF RELAY BOX.
Measure resistance between relay box connector and
valve relay installing point.
: Connector & terminal
Valve relay installing point No. 30 (+)—To
(F50) No. 2 ()
Is resistance more than 1 MΩ?
: Go to step8K11.
: Replace relay box.
B4M0869B
8K11CHECK BROKEN WIRE IN GROUND CIR-
CUIT OF RELAY BOX.
Measure resistance between relay box connector and
valve relay installing point.
: Connector & terminal
To (F50) No. 3—Valve relay installing point
No. 87a
Is resistance less than 0.5Ω?
: Go to step8K12.
: Replace relay box.
81
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0870B
8K12CHECK BATTERY SHORT IN GROUND
CIRCUIT OF RELAY BOX.
1) Turn ignition switch to ON.
2) Measure voltage between relay box connector and
chassis ground.
: Connector & terminal
To (F50) No. 3 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace relay box and check all fuses.
3) Turn ignition switch to OFF.
4) Measure voltage between relay box connector and
chassis ground.
: Connector & terminal
To (F50) No. 3 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8K13.
: Replace relay box and check all fuses.
B4M0871B
8K13CHECK BROKEN WIRE IN CONTROL
CIRCUIT OF RELAY BOX.
1) Install valve relay to relay box.
2) Measure resistance between relay box connector termi-
nals.
: Connector & terminal
To (F50) No. 1—No. 5
Is resistance 103±10Ω?
: Go to step8K14.
: Replace relay box.
B4M0872B
8K14CHECK GROUND SHORT IN CONTROL
CIRCUIT OF RELAY BOX.
Measure resistance between relay box connector and
chassis ground.
: Connector & terminal
To (F50) No. 1—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8K15.
: Replace relay box and check all fuses.
82
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code