1997 SUBARU LEGACY ABS

7B1CHECK INSTALLATION OF ABSCM&H/U
CONNECTOR.
Turn ignition switch to OFF.
: Is ABSCM&H/U connector inserted into
ABSCM until the clamp locks onto it?
: Go to step7B2.
: Insert ABSCM&H/U connector into ABSCM&H/U
until the clamp locks onto it.
B4M0800A
7B2
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 step7B3.
: Repair diagnosis terminal harness.
B4M1233A
7B3
CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal to diagnosis connector
(B82) No. 6.
3) Disconnect connector from ABSCM&H/U.
4) Measure resistance between ABSCM&H/U connector
and chassis ground.
: Connector & terminal
(F49) No. 4—Chassis ground:
Is the resistance less than 0.5Ω?
: Go to step7B4.
: Repair harness connector between ABSCM&H/U
and diagnosis connector.
22
4-4dBRAKES [ABS 5.3i TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0430
7B4
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 the voltage between 10 and 15 V?
: Go to step7B5.
: Repair generator.
7B5
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Is there poor contact at battery terminal?
: Repair battery terminal.
: Go to step7B6.
B4M1234A
7B6
CHECK POWER SUPPLY OF ABSCM.
1) Disconnect connector from ABSCM&H/U.
2) Start engine.
3) Idle the engine.
4) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 1 (+)—Chassis ground ():
: Is the voltage between 10 and 15 V?
: Go to step7B7.
: Repair ABSCM&H/U power supply circuit.
7B7
CHECK WIRING HARNESS.
1) Disconnect connector (F2) from connector (B100).
2) Turn ignition switch to ON.
: Does the ABS warning light remain off?
: Go to step7B8.
: Repair front wiring harness.
B4M1235A
7B8
CHECK PROJECTION AT ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Check for broken projection at the ABSCM&H/U termi-
nal.
: Are the projection broken?
: Go to step7B9.
: Replace ABSCM&H/U.
23
4-4dBRAKES [ABS 5.3i TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M1237A
7B9
CHECK ABSCM&H/U.
Measure resistance between ABSCM&H/U terminals.
Terminals
No. 21—No. 23:
: Is the resistance more than 1 MΩ?
: Go to step7B10.
: Replace ABSCM&H/U.
B4M1236A
7B10
CHECK WIRING HARNESS.
Measure resistance between connector (F2) and chassis
ground.
Connector & terminal
(F2) No. 9—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step7B11.
: Repair harness.
B4M1236A
7B11
CHECK WIRING HARNESS.
1) Connect connector to ABSCM&H/U.
2) Measure resistance between connector (F2) and chas-
sis ground.
Connector & terminal
(F2) No. 9—Chassis ground:
: Is the resistance more than 1 MΩ?
: Go to step7B12.
: Repair harness.
7B12CHECK POOR CONTACT IN ABSCM&H/U
CONNECTOR.
: Is there poor contact in ABSCM&H/U con-
nector?
: Repair connector.
: Replace ABSCM&H/U.
24
4-4dBRAKES [ABS 5.3i 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.
WIRING DIAGRAM:
B4M1230
25
4-4dBRAKES [ABS 5.3i TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

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.
B4M1233A
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&H/U.
4) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 4—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step7C3.
: Repair harness connector between ABSCM&H/U
and diagnosis connector.
7C3CHECK POOR CONTACT IN ABSCM&H/U
CONNECTOR.
: Is there poor contact in ABSCM&H/U con-
nector?
: Repair connector.
: Replace ABSCM&H/U.
26
4-4dBRAKES [ABS 5.3i TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

8. Diagnostics Chart with Trouble Code
by ABS Warning Light
A: LIST OF TROUBLE CODE
Trouble code Contents of diagnosis Ref. to
11Start code

Trouble code is shown after start code.

Only start code is shown in normal condition.—
21
Abnormal ABS sensor
(Open circuit or input voltage too high)Front right ABS sensor 4-4d [T8B0]
23 Front left ABS sensor 4-4d [T8C0]
25 Rear right ABS sensor 4-4d [T8D0]
27 Rear left ABS sensor 4-4d [T8E0]
22
Abnormal ABS sensor
(Abnormal ABS sensor signal)Front right ABS sensor 4-4d [T8F0]
24 Front left ABS sensor 4-4d [T8G0]
26 Rear right ABS sensor 4-4d [T8H0]
28 Rear left ABS sensor 4-4d [T8I0]
29 Any one of four 4-4d [T8J0]
31
Abnormal solenoid valve circuit(s) in ABS
control module and hydraulic unitFront right inlet valve 4-4d [T8K0]
32 Front right outlet valve 4-4d [T8O0]
33 Front left inlet valve 4-4d [T8L0]
34 Front left outlet valve 4-4d [T8P0]
35 Rear right inlet valve 4-4d [T8M0]
36 Rear right outlet valve 4-4d [T8Q0]
37 Rear left inlet valve 4-4d [T8N0]
38 Rear left outlet valve 4-4d [T8R0]
41 Abnormal ABS control module 4-4d [T8S0]
42 Source voltage is abnormal. 4-4d [T8T0]
44 A combination of AT control abnormal 4-4d [T8U0]
51 Abnormal valve relay4-4d [T8V0]
52 Abnormal motor and/or motor relay 4-4d [T8W0]
54 Abnormal stop light switch 4-4d [T8X0]
56 Abnormal G sensor output voltage 4-4d [T8Y0]
27
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B: TROUBLE CODE 21 (FRONT RH)
C: TROUBLE CODE 23 (FRONT LH)
D: TROUBLE CODE 25 (REAR RH)
E: TROUBLE CODE 27 (REAR LH)
—ABNORMAL ABS SENSOR (OPEN CIRCUIT
OR INPUT VOLTAGE TOO HIGH)—
DIAGNOSIS:

Faulty ABS sensor (Broken wire, input voltage too high)

Faulty harness connector
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1238
28
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light

B4M0806E
B4M1036C
8E1
CHECK ABS SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABS sensor.
3) Measure resistance of ABS sensor connector terminals.
Terminal
Front RH No. 1—No. 2:
Front LH No. 1—No. 2:
Rear RH No. 1—No. 2:
Rear LH No. 1—No. 2:
: Is the resistance between 0.8 and 1.2 kΩ?
: Go to step8E2.
: Replace ABS sensor.
B4M0807E
B4M1037C
8E2CHECK BATTERY SHORT OF ABS SEN-
SOR.
1) Disconnect connector from ABSCM&H/U.
2) Measure voltage between ABS sensor and chassis
ground.
Terminal
Front RH No. 1 (+)—Chassis ground ():
Front LH No. 1 (+)—Chassis ground ():
Rear RH No. 1 (+)—Chassis ground ():
Rear LH No. 1 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step8E3.
: Replace ABS sensor.
29
4-4dBRAKES [ABS 5.3i TYPE]
8. Diagnostics Chart with Trouble Code by ABS Warning Light