SUBARU LEGACY 1996 Service Repair Manual

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.
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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
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8. Diagnostics Chart with Trouble Code

B4M0873B
8K15CHECK BATTERY SHORT IN CONTROL
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. 1 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace relay box. Check fuse No. 19 and
SBF45A.
3) Turn ignition switch to OFF.
4) Measure voltage between relay box connector and
chassis ground.
: Connector & terminal
To (F50) No. 1 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8K16.
: Replace relay box. Check fuse No. 19 and
SBF45A.
B4M0874A
8K16CHECK BROKEN WIRE IN CONTROL
SYSTEM HARNESS OF VALVE RELAY.
1) Connect connector (F50) to relay box.
2) Measure resistance between ABSCM connector termi-
nals.
: Connector & terminal
(F49) No. 27—No. 47
Is resistance 103±10Ω?
: Go to step8K17.
: Repair harness between ABSCM and relay box.
Check fuse No. 18.
B4M0875A
8K17CHECK GROUND SHORT IN CONTROL
SYSTEM HARNESS OF VALVE RELAY.
Measure resistance between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 27—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8K18.
: Repair harness between ABSCM and relay box.
Check fuse No. 18.
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8. Diagnostics Chart with Trouble Code

B4M0876A
8K18CHECK BATTERY SHORT IN CONTROL
SYSTEM HARNESS OF VALVE RELAY.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 27 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between ABSCM and relay box
and check all fuses.
3) Turn ignition switch to OFF.
4) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 27 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8K19.
: Repair harness between ABSCM and relay box
and check all fuses.
B4M0824B
8K19CHECK RESISTANCE OF INLET SOLE-
NOID VALVE.
1) Disconnect connector from hydraulic unit.
2) Measure resistance between hydraulic unit connector
terminals.
: Connector & terminal
To (F9) No. 4—to (ABS1) No. 2
To (F9) No. 1—to (ABS1) No. 2
To (F9) No. 2—to (ABS1) No. 2
To (F9) No. 3—to (ABS1) No. 2
Is resistance 8.5±0.7Ω?
: Go to step8K20.
: Replace hydraulic unit.
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8. Diagnostics Chart with Trouble Code

B4M0831B
8K20CHECK RESISTANCE OF OUTLET SOLE-
NOID VALVE.
Measure resistance between hydraulic unit connector ter-
minals.
: Connector & terminal
To (F9) No. 8—to (ABS1) No. 2
To (F9) No. 5—to (ABS1) No. 2
To (F9) No. 6—to (ABS1) No. 2
To (F9) No. 7—to (ABS1) No. 2
Is resistance 4.3±0.5Ω?
: Go to step8K21.
: Replace hydraulic unit.
B4M0879B
8K21CHECK GROUND SHORT OF SOLENOID
VA LV E .
Measure resistance between hydraulic unit connector and
chassis ground.
: Connector & terminal
To (F9) No. 4—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8K22.
: Replace hydraulic unit and check all fuses.
B4M0880B
8K22CHECK BATTERY SHORT OF SOLENOID
VA LV E .
1) Turn ignition switch to ON.
2) Measure voltage between hydraulic unit connector and
chassis ground.
: Connector & terminal
To (F9) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace hydraulic unit and check all fuses.
3) Turn ignition switch to OFF.
4) Measure voltage between hydraulic unit connector and
chassis ground.
: Connector & terminal
To (F9) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8K23.
: Replace hydraulic unit and check all fuses.
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8. Diagnostics Chart with Trouble Code

B4M0881A
8K23
CHECK BATTERY SHORT OF HARNESS.
1) Disconnect connector from hydraulic unit.
2) Turn ignition switch to ON.
3) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 30 (+)—Chassis ground ()
(F49) No. 24 (+)—Chassis ground ()
(F49) No. 23 (+)—Chassis ground ()
(F49) No. 31 (+)—Chassis ground ()
(F49) No. 3 (+)—Chassis ground ()
(F49) No. 51 (+)—Chassis ground ()
(F49) No. 50 (+)—Chassis ground ()
(F49) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between hydraulic unit and
ABSCM and check all fuses.
4) Turn ignition switch to OFF.
5) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 30 (+)—Chassis ground ()
(F49) No. 24 (+)—Chassis ground ()
(F49) No. 23 (+)—Chassis ground ()
(F49) No. 31 (+)—Chassis ground ()
(F49) No. 3 (+)—Chassis ground ()
(F49) No. 51 (+)—Chassis ground ()
(F49) No. 50 (+)—Chassis ground ()
(F49) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8K24.
: Repair harness between hydraulic unit and
ABSCM and check all fuses.
86
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8. Diagnostics Chart with Trouble Code

B4M0882A
8K24
CHECK GROUND SHORT OF HARNESS.
Measure resistance between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 30—Chassis ground
(F49) No. 24—Chassis ground
(F49) No. 23—Chassis ground
(F49) No. 31—Chassis ground
(F49) No. 3—Chassis ground
(F49) No. 51—Chassis ground
(F49) No. 50—Chassis ground
(F49) No. 4—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8K25.
: Repair harness between hydraulic unit and
ABSCM.
B4M0883A
8K25CHECK HARNESS CONNECTOR
BETWEEN ABSCM AND HYDRAULIC
UNIT.
1) Connect connector to hydraulic unit.
2) Measure resistance between ABSCM connector termi-
nals.
: Connector & terminal
(F49) No. 30—No. 1
(F49) No. 24—No. 1
(F49) No. 23—No. 1
(F49) No. 31—No. 1
Is resistance 9.0±0.7Ω?
: Go to next.
: Repair harness connector between hydraulic unit
and ABSCM.
B4M0884A
: Connector & terminal
(F49) No. 3—No. 1
(F49) No. 51—No. 1
(F49) No. 50—No. 1
(F49) No. 4—No. 1
Is resistance 4.8±0.5Ω?
: Go to step8K26.
: Repair harness connector between hydraulic unit
and ABSCM.
87
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

8K26CHECK POOR CONTACT IN CONNEC-
TOR BETWEEN ABSCM AND HYDRAU-
LIC UNIT.
: Is there poor contact in connector between
ABSCM and hydraulic unit?
: Repair connector.
: Go to step8K27.
8K27
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.
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8. Diagnostics Chart with Trouble Code

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

Faulty motor

Faulty motor relay

Faulty harness connector
TROUBLE SYMPTOM:

ABS does not operate.
8L1.Check resistance of motor relay.
8L2.Check contact point of motor relay.
8L3.Check short of motor relay.
8L4.Check input voltage of relay box.
8L5.Check input voltage of motor relay.
8L6.Check broken wire in contact point circuit of
relay box.
8L7.Check ground short in contact point circuit of
relay box.
8L8.Check battery short in contact point circuit of
relay box.
8L9.Check broken wire in monitor system circuit of
relay box.
8L10.Check broken wire in control circuit of relay
box.
8L11.Check ground short in control circuit of relay
box.
8L12.Check battery short in control circuit of relay
box.
8L13.Check broken wire in monitor system harness.
8L14.Check broken wire in relay control system
harness.
8L15.Check ground short between relay box and
ABSCM.
Continues to next page.















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8. Diagnostics Chart with Trouble Code

From the former page.
8L16.
Check battery short between relay box and
ABSCM.
8L17.Check ground short at ABSCM monitor
terminal.
8L18.Check battery short at ABSCM monitor
terminal.
8L19.Check motor ground.
8L20.Check ABSCM motor drive terminal.
8L21.Check motor operation.
8L22.Check poor contact in connector between
hydraulic unit, relay box and ABSCM.
8L23.Check ABSCM.








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8. Diagnostics Chart with Trouble Code