SUBARU LEGACY 1997 Service Repair Manual

B4M0833B
8F3CHECK 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 step8F4.
: Replace hydraulic unit.
B4M0834A
8F4
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.
56
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

3) Turn ignition switch to OFF.
4) 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 step8F5.
: Repair harness between ABSCM and hydraulic
unit.
B4M0835A
8F5
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 step8F6.
: Repair harness between ABSCM and hydraulic
unit.
57
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0836A
8F6CHECK 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 step8F7.
: Repair harness connector between ABSCM and
hydraulic unit.
8F7CHECK 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 step8F8.
8F8
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.
58
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

G: TROUBLE CODE 41
—ABNORMAL ABS CONTROL MODULE—
DIAGNOSIS:

Faulty ABSCM
TROUBLE SYMPTOM:

ABS does not operate.
8G1.Check ground circuit of ABSCM.
8G2.Check poor contact in connector between
battery, ignition switch and ABSCM.
8G3.Check sources of signal noise.
8G4.Check ABSCM.
WIRING DIAGRAM:
B4M0837



59
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0838A
8G1
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 step8G2.
: Repair ABSCM ground harness.
8G2CHECK 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 step8G3.
8G3
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 step8G4.
60
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

8G4
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.
61
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

H: TROUBLE CODE 42
—SOURCE VOLTAGE IS LOW.—
DIAGNOSIS:

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

ABS does not operate.
8H1.Check generator.
8H2.Check battery terminal.
8H3.Check input voltage of ABSCM.
8H4.Check ground circuit of ABSCM.
8H5.Check poor contact in connector between
generator, battery and ABSCM.
8H6.Check ABSCM.





62
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:
B4M1039
63
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0430
8H1
CHECK GENERATOR.
1) Start engine.
2) Idling after warm-up.
3) Measure voltage between generator B terminal and
chassis ground.
: Terminal
Generator B terminal—Chassis ground
Is voltage 10—15 V?
: Go to step8H2.
: Repair generator.
8H2
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Are the positive and negative battery termi-
nals tightly clamped?
: Go to step8H3.
: Tighten the clamp of terminal.
B4M0842A
8H3
CHECK INPUT VOLTAGE OF ABSCM.
1) Disconnect connector from ABSCM.
2) Run the engine at idle.
3) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 28 (+)—Chassis ground ()
Is voltage 10—15 V?
: Go to step8H4.
: Repair harness connector between battery, igni-
tion switch and ABSCM.
64
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0843A
8H4
CHECK GROUND CIRCUIT OF ABSCM.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM connector and
chassis ground.
: Connector & terminal
(F49) No. 1—Chassis ground
Is resistance less than 0.5Ω?
: Go to step8H5.
: Repair ABSCM ground harness.
8H5CHECK POOR CONTACT IN CONNEC-
TOR BETWEEN GENERATOR, BATTERY
AND ABSCM.
: Is there poor contact in connectors between
generator, battery and ABSCM?
: Repair connector.
: Go to step8H6.
8H6
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.
65
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code