SUBARU LEGACY 1997 Service Repair Manual

B4M0833B
10U9CHECK BATTERY SHORT OF SOLENOID
VA LV E .
1) Turn ignition switch to OFF.
2) Disconnect two connectors (ABS1, F9) from hydraulic
unit.
3) Disconnect connector from ABSCM.
4) Turn ignition switch to ON.
5) Measure voltage between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
32/to (F9) No. 8 (+)—Chassis ground ()
34/to (F9) No. 5 (+)—Chassis ground ()
36/to (F9) No. 6 (+)—Chassis ground ()
38/to (F9) No. 7 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace hydraulic unit.
6) Turn ignition switch to OFF.
7) Measure voltage between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
32/to (F9) No. 8 (+)—Chassis ground ()
34/to (F9) No. 5 (+)—Chassis ground ()
36/to (F9) No. 6 (+)—Chassis ground ()
38/to (F9) No. 7 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step10U10.
: Replace hydraulic unit.
B4M0834A
10U10
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM connector and chas-
sis ground.
: Trouble code/Connector & terminal
32/(F49) No. 3 (+)—Chassis ground ()
34/(F49) No. 51 (+)—Chassis ground ()
36/(F49) No. 50 (+)—Chassis ground ()
38/(F49) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between ABSCM and hydraulic
unit.
3) Turn ignition switch to OFF.
4) Measure voltage between ABSCM connector and chas-
sis ground.
176
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

: Trouble code/Connector & terminal
32/(F49) No. 3 (+)—Chassis ground ()
34/(F49) No. 51 (+)—Chassis ground ()
36/(F49) No. 50 (+)—Chassis ground ()
38/(F49) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Replace ABSCM.
: Repair harness between ABSCM and hydraulic
unit.
B4M0831B
10U11CHECK RESISTANCE OF SOLENOID
VA LV E .
1) Turn ignition switch to OFF.
2) Disconnect two connectors (ABS1, F9) from hydraulic
unit.
3) Measure resistance between hydraulic unit connector
terminals.
: Trouble code/Connector & terminal
32/to (F9) No. 8—to (ABS1) No. 2
34/to (F9) No. 5—to (ABS1) No. 2
36/to (F9) No. 6—to (ABS1) No. 2
38/to (F9) No. 7—to (ABS1) No. 2
Is resistance 4.3±0.5Ω?
: Go to step10U12.
: Replace hydraulic unit.
B4M0832B
10U12CHECK GROUND SHORT OF SOLENOID
VA LV E .
Measure resistance between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
32/to (F9) No. 8—Chassis ground
34/to (F9) No. 5—Chassis ground
36/to (F9) No. 6—Chassis ground
38/to (F9) No. 7—Chassis ground
Is resistance more than 1 MΩ?
: Go to step10U13.
: Replace hydraulic unit.
177
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

B4M0833B
10U13CHECK BATTERY SHORT OF SOLENOID
VA LV E .
1) Disconnect connector from ABSCM.
2) Turn ignition switch to ON.
3) Measure voltage between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
32/to (F9) No. 8 (+)—Chassis ground ()
34/to (F9) No. 5 (+)—Chassis ground ()
36/to (F9) No. 6 (+)—Chassis ground ()
38/to (F9) No. 7 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace hydraulic unit.
4) Turn ignition switch to OFF.
5) Measure voltage between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
32/to (F9) No. 8 (+)—Chassis ground ()
34/to (F9) No. 5 (+)—Chassis ground ()
36/to (F9) No. 6 (+)—Chassis ground ()
38/to (F9) No. 7 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step10U14.
: Replace hydraulic unit.
B4M0834A
10U14
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM connector and chas-
sis ground.
: Trouble code/Connector & terminal
32/(F49) No. 3 (+)—Chassis ground ()
34/(F49) No. 51 (+)—Chassis ground ()
36/(F49) No. 50 (+)—Chassis ground ()
38/(F49) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between ABSCM and hydraulic
unit.
3) Turn ignition switch to OFF.
4) Measure voltage between ABSCM connector and chas-
sis ground.
178
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

: Trouble code/Connector & terminal
32/(F49) No. 3 (+)—Chassis ground ()
34/(F49) No. 51 (+)—Chassis ground ()
36/(F49) No. 50 (+)—Chassis ground ()
38/(F49) No. 4 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step10U15.
: Repair harness between ABSCM and hydraulic
unit.
B4M0835A
10U15
CHECK GROUND SHORT OF HARNESS.
Measure resistance between ABSCM connector and chas-
sis ground.
: Trouble code/Connector & terminal
32/(F49) No. 3—Chassis ground
34/(F49) No. 51—Chassis ground
36/(F49) No. 50—Chassis ground
38/(F49) No. 4—Chassis ground
Is resistance more than 1 MΩ?
: Go to step10U16.
: Repair harness between ABSCM and hydraulic
unit.
B4M0836A
10U16CHECK HARNESS CONNECTOR
BETWEEN ABSCM AND HYDRAULIC
UNIT.
1) Connect connector to hydraulic unit.
2) Measure resistance between ABSCM connector termi-
nals.
: Trouble code/Connector & terminal
32/(F49) No. 3—No. 1
34/(F49) No. 51—No. 1
36/(F49) No. 50—No. 1
38/(F49) No. 4—No. 1
Is resistance 4.8±0.5Ω?
: Go to step10U17.
: Repair harness connector between ABSCM and
hydraulic unit.
179
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

10U17CHECK POOR CONTACT IN CONNEC-
TOR BETWEEN ABSCM AND HYDRAU-
LIC UNIT.
: Is there poor contact in connectors between
ABSCM and hydraulic unit?
: Repair connector.
: Go to step10U18.
10U18
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.
180
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

B4M0962
V: 41 ECU
—ABNORMAL ABS CONTROL MODULE—
DIAGNOSIS:

Faulty ABSCM
TROUBLE SYMPTOM:

ABS does not operate.
10V1.Check ground circuit of ABSCM.
10V2.Check poor contact in connector between
battery, ignition switch and ABSCM.
10V3.Check sources of signal noise.
10V4.Check ABSCM.
WIRING DIAGRAM:
B4M0837



181
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

B4M0838A
10V1
CHECK GROUND CIRCUIT OF ABSCM.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABSCM.
3) Measure resistance between ABSCM and chassis
ground.
: Connector & terminal
(F49) No. 1—Chassis ground
(F49) No. 55—Chassis ground
Is resistance less than 0.5Ω?
: Go to step10V2.
: Repair ABSCM ground harness.
10V2CHECK POOR CONTACT IN CONNEC-
TORS BETWEEN BATTERY, IGNITION
SWITCH AND ABSCM.
: Is there poor contact in connectors between
battery, ignition switch and ABSCM?
: Repair connector.
: Go to step10V3.
10V3
CHECK SOURCES OF SIGNAL NOISE.
: Is the car telephone or the wireless trans-
mitter properly installed?
: Go to next.
: Properly install the car telephone or the wireless
transmitter.
: Are noise sources (such as an antenna)
installed near the sensor harness?
: Install the noise sources apart from the sensor
harness.
: Go to step10V4.
182
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

10V4
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.
183
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

B4M0963
W: 42 LOW VOLTAGE
—SOURCE VOLTAGE IS LOW.—
DIAGNOSIS:

Power source voltage of the ABSCM is low.
TROUBLE SYMPTOM:

ABS does not operate.
10W1.Check generator.
10W2.Check battery terminal.
10W3.Check input voltage of ABSCM.
10W4.Check ground circuit of ABSCM.
10W5.Check poor contact in connector between
generator, battery and ABSCM.
10W6.Check ABSCM.





184
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

WIRING DIAGRAM:
B4M1039
185
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor