SUBARU LEGACY 1997 Service Repair Manual

B4M0963
W: TROUBLE CODE 42 LOW VOLTAGE
—SOURCE VOLTAGE IS LOW—
DIAGNOSIS:

Power source voltage of the ABSCM&H/U is low.
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1245
135
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0430
10W1
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 the voltage between 10 V and 15 V?
: Go to step10W2.
: Repair generator.
10W2
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Are the positive and negative battery termi-
nals tightly clamped?
: Go to step10W3.
: Tighten the clamp of terminal.
B4M1234A
10W3CHECK INPUT VOLTAGE OF
ABSCM&H/U.
1) Disconnect connector from ABSCM&H/U.
2) Run the engine at idle.
3) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 1 (+)—Chassis ground ():
: Is the voltage between 10 V and 15 V?
: Go to step10W4.
: Repair harness connector between battery, igni-
tion switch and ABSCM&H/U.
136
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1243A
10W4CHECK GROUND CIRCUIT OF
ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 23—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step10W5.
: Repair ABSCM&H/U ground harness.
10W5CHECK POOR CONTACT IN CONNEC-
TORS.
: Is there poor contact in connectors between
generator, battery and ABSCM&H/U? <Ref.
to FOREWORD [T3C1].>
: Repair connector.
: Go to step10W6.
10W6
CHECK ABSCM&H/U.
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&H/U.
: Go to step10W7.
10W7CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
137
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1268
X: TROUBLE CODE 42 LOW VOLTAGE
—SOURCE VOLTAGE IS HIGH—
DIAGNOSIS:

Power source voltage of the ABSCM&H/U is high.
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1245
138
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0430
10X1
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 the voltage between 10 V and 17 V?
: Go to step10X2.
: Repair generator.
10X2
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Are the positive and negative battery termi-
nals tightly clamped?
: Go to step10X3.
: Tighten the clamp of terminal.
B4M1234A
10X3CHECK INPUT VOLTAGE OF
ABSCM&H/U.
1) Disconnect connector from ABSCM&H/U.
2) Run the engine at idle.
3) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 1 (+)—Chassis ground ():
: Is the voltage between 10 V and 17 V?
: Go to step10X4.
: Repair harness connector between battery, igni-
tion switch and ABSCM&H/U.
139
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M1243A
10X4CHECK GROUND CIRCUIT OF
ABSCM&H/U.
1) Turn ignition switch to OFF.
2) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 23—Chassis ground:
: Is the resistance less than 0.5Ω?
: Go to step10X5.
: Repair ABSCM&H/U ground harness.
10X5CHECK POOR CONTACT IN CONNEC-
TORS.
: Is there poor contact in connectors between
generator, battery and ABSCM&H/U? <Ref.
to FOREWORD [T3C1].>
: Repair connector.
: Go to step10X6.
10X6
CHECK ABSCM&H/U.
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&H/U.
: Go to step10X7.
10X7CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
140
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0964
Y: TROUBLE CODE 44 CCM LINE
—A COMBINATION OF AT CONTROL
ABNORMALS—
DIAGNOSIS:

Combination of AT control faults
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1247
141
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

H4M1117
10Y1CHECK SPECIFICATIONS OF
ABSCM&H/U USING SELECT MONITOR.
1) Press [F], [0] and [0] on the select monitor.
2) Read the select monitor display.
: Is an ABSCM&H/U for AT model installed on
a MT model?
: Replace ABSCM&H/U.
: Go to step10Y2.
B4M1249A
10Y2
CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect two connectors from TCM.
3) Disconnect connector from ABSCM&H/U.
4) Measure resistance between ABSCM&H/U connector
and chassis ground.
Connector & terminal
(F49) No. 3—Chassis ground:
: Is the resistance more than 1 MΩ?
: Go to step10Y3.
: Repair harness between TCM and ABSCM&H/U.
B4M1251A
10Y3
CHECK TCM.
1) Connect all connectors to TCM.
2) Turn ignition switch to ON.
3) Measure voltage between TCM connector terminal and
chassis ground.
Connector & terminal
(B55) No. 5 (+)—Chassis ground ():
: Is the voltage between 10 V and 15 V?
: Go to step10Y5.
: Go to step10Y4.
142
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

10Y4
CHECK AT.
: Is the AT functioning normally?
: Replace TCM.
: Repair AT.
B4M1252A
10Y5
CHECK OPEN CIRCUIT OF HARNESS.
Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 3 (+)—Chassis ground ():
(F49) No. 31 (+)—Chassis ground ():
: Is the voltage more than 10 V?
: Go to step10Y6.
: Repair harness/connector between AT control
module and ABSCM&H/U.
10Y6CHECK POOR CONTACT IN CONNEC-
TORS.
: Is there poor contact in connectors between
AT control module and ABSCM&H/U? <Ref.
to FOREWORD [T3C1].>
: Repair connector.
: Go to step10Y7.
10Y7
CHECK ABSCM&H/U.
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&H/U.
: Go to step10Y8.
10Y8CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
143
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0965
Z: TROUBLE CODE 44 CCM OPEN
—A COMBINATION OF AT CONTROL
ABNORMALS—
DIAGNOSIS:

Combination of AT control faults
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1247
144
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor