1996 SUBARU LEGACY Brakes

WIRING DIAGRAM:
B4M1034
7B1CHECK INSTALLATION OF ABSCM CON-
NECTOR.
Turn ignition switch to OFF.
: Is ABSCM connector inserted into ABSCM
until the clamp locks onto it?
: Go to step7B2.
: Insert ABSCM connector into ABSCM until the
clamp locks onto it.
19
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0430
7B2
CHECK GENERATOR.
1) Start the engine.
2) Idle the engine.
3) Measure voltage between generator and chassis
ground.
: Terminal
Generator B terminal (+)—Chassis ground
():
Is voltage 10—15 V?
: Go to step7B3.
: Repair generator.
7B3
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Is there poor contact at battery terminal?
: Repair battery terminal.
: Go to step7B4.
B4M0796A
7B4
CHECK POWER SUPPLY OF ABSCM.
1) Disconnect connector from ABSCM.
2) Start engine.
3) Idle the engine.
4) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 28 (+)—Chassis ground ():
Is voltage 10—15 V?
: Go to step7B5.
: Repair ABSCM power supply circuit.
20
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0797A
7B5
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:
(F49) No. 55—Chassis ground:
Is resistance less than 0.5Ω?
: Go to step7B6.
: Repair ABSCM ground harness.
7B6
CHECK WIRING HARNESS.
1) Disconnect connector (F50) from relay box.
2) Turn ignition switch to ON.
: Does the ABS warning light remain off?
: Go to step7B7.
: Repair front wiring harness.
7B7
CHECK RELAY BOX.
1) Turn ignition switch to OFF.
2) Connect connector (F50) to relay box.
3) Remove valve relay from relay box.
4) Disconnect connector (ABS1) from hydraulic control
unit.
5) Turn ignition switch to ON.
: Does the ABS warning light remain off?
: Go to step7B8.
: Repair relay box and check fuse.
21
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0798A
B4M0811A
7B8
CHECK VALVE RELAY.
1) Measure resistance between valve relay terminal and
terminal.
: Terminals
No. 30—No. 87:
Is resistance more than 1 MΩ?
No. 30—No. 87a:
Is resistance less than 0.5Ω?
: Go to next step.
: Replace valve relay.
2) Connect battery to valve relay terminal No. 85 and No.
86.
3) Measure resistance between valve relay terminals.
: Terminals
No. 30—No. 87:
Is resistance less than 0.5Ω?
No. 30—No. 87a:
Is resistance more than 1 MΩ?
: Go to step7B9.
: Replace valve relay.
7B9
CHECK HYDRAULIC CONTROL UNIT.
1) Turn ignition switch to OFF.
2) Connect connector (ABS1) to hydraulic control unit.
3) Turn ignition switch to ON.
: Is the ABS warning light off?
: Go to step7B10.
: Replace hydraulic control unit and check fuse No.
19.
22
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0800A
7B10
CHECK DIAGNOSIS TERMINAL.
Measure resistance between diagnosis terminals (B81)
and chassis ground.
: Terminals
Diagnosis terminal (A)—Chassis ground:
Diagnosis terminal (B)—Chassis ground:
Is the resistance less than 1Ω?
: Go to step7B11.
: Repair diagnosis terminal harness.
B4M0801A
7B11
CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal to diagnosis connector
(B82) No. 6.
3) Disconnect connector from ABSCM.
4) Measure resistance between ABSCM connector and
chassis ground.
: Connector & terminal
(F49) No. 13—Chassis ground:
Is the resistance less than 1Ω?
: Go to step7B12.
: Repair harness connector between ABSCM and
diagnosis connector.
7B12CHECK POOR CONTACT IN ABSCM
CONNECTOR.
: Is there poor contact in ABSCM connector?
: Repair connector.
: Replace ABSCM.
23
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

C: TROUBLE CODE DOES NOT APPEAR.
DIAGNOSIS:

Diagnosis circuit is open.
TROUBLE SYMPTOM:

The ABS warning light turns on or off normally but the
start code cannot be read out in the diagnostic mode.
7C1.Check diagnosis terminal.
7C2.Check diagnosis line.
7C3.Check poor contact in ABSCM connector.


24
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

WIRING DIAGRAM:
B4M1034
B4M0800A
7C1
CHECK DIAGNOSIS TERMINAL.
Measure resistance between diagnosis terminals (B81)
and chassis ground.
: Terminals
Diagnosis terminal (A)—Chassis ground:
Diagnosis terminal (B)—Chassis ground:
Is the resistance less than 0.5Ω?
: Go to step7C2.
: Repair diagnosis terminal harness.
25
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0801A
7C2
CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal to diagnosis connector
(B82) No. 6.
3) Disconnect connector from ABSCM.
4) Measure resistance between ABSCM connector and
chassis ground.
: Connector & terminal
(F49) No. 13—Chassis ground:
Is the resistance less than 0.5Ω?
: Go to step7C3.
: Repair harness connector between ABSCM and
diagnosis connector.
7C3CHECK POOR CONTACT IN ABSCM
CONNECTOR.
: Is there poor contact in ABSCM connector?
: Repair connector.
: Replace ABSCM.
26
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure