SUBARU LEGACY 1996 Service Repair Manual

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

I: TROUBLE CODE 44
—A COMBINATION OF AT CONTROL
ABNORMALS—
DIAGNOSIS:

Combination of AT control faults
TROUBLE SYMPTOM:

ABS does not operate.
8I1.Check specifications of the ABSCM.
8I2.Check ground short of harness.
8I3.Check battery short of harness.
8I4.Check AT control module.
8I5.Check open circuit of harness.
8I6.Check poor contact in connector between AT
control module and ABSCM.
8I7.Check ABSCM.






66
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:
B4M1040
B4M0910A
8I1CHECK SPECIFICATIONS OF THE
ABSCM.
Check specifications of the plate attached to the ABSCM.
: Is an ABSCM for AT model installed on a MT
model?
: Replace ABSCM.
: Go to step8I2.
67
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

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

8I6CHECK POOR CONTACT IN CONNEC-
TOR BETWEEN AT CONTROL MODULE
AND ABSCM.
: Is there poor contact in connectors between
AT control module and ABSCM?
: Repair connector.
: Go to step8I7.
8I7
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.
70
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code