1997 SUBARU LEGACY battery

B4M1234A
10AE3CHECK INPUT VOLTAGE OF
ABSCM&H/U.
1) Run the engine at idle.
2) 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 step10AE4.
: Repair harness connector between battery, igni-
tion switch and ABSCM&H/U.
B4M1243A
10AE4CHECK 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 step10AE5.
: Repair ABSCM&H/U ground harness.
10AE5
CHECK MOTOR OPERATION.
Operate the sequence control.
NOTE:
Use the diagnosis connector to operate the sequence con-
trol.
: Can motor revolution noise (buzz) be heard
when carrying out the sequence control?
: Go to step10AE6.
: Replace hydraulic unit.
159
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

10AE6CHECK POOR CONTACT IN CONNEC-
TORS.
Turn ignition switch to OFF.
: Is there poor contact in connector between
generator, battery and ABSCM&H/U? to FOREWORD [T3C1].>
: Repair connector.
: Go to step10AE7.
10AE7
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 step10AE8.
10AE8CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
160
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0982
AH: TROUBLE CODE 56 G SENSOR +B
—BATTERY SHORT OF G SENSOR—
DIAGNOSIS:

Faulty G sensor output voltage
TROUBLE SYMPTOM:

ABS does not operate.
WIRING DIAGRAM:
B4M1260
171
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

B4M0927
10AH1CHECK OUTPUT OF G SENSOR USING
SELECT MONITOR.
1) Press [F], [1] and [0] on the select monitor.
2) Read the select monitor display.
: Is the indicated reading between 2.1 and 2.5
V when the G sensor is in horizontal posi-
tion?
: Replace ABSCM&H/U.
: Go to step10AH2.
B4M1263A
10AH2
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Remove console box.
3) Disconnect connector from G sensor.
4) Disconnect connector from ABSCM&H/U.
5) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 6 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step10AH3.
: Repair harness between G sensor and
ABSCM&H/U.
B4M1263A
10AH3
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM&H/U connector and
chassis ground.
Connector & terminal
(F49) No. 6 (+)—Chassis ground ():
: Is the voltage less than 1 V?
: Go to step10AH4.
: Repair harness between G sensor and
ABSCM&H/U.
172
4-4dBRAKES [ABS 5.3i TYPE]
10. Diagnostics Chart with Select Monitor

E: DIAGNOSTICS PROCEDURE
Airbag warning light stays on after 8 seconds.
1) Perform on-board diagnostic.
2) Are trouble codes 2, 4, 12, 13, 22, 23, 24 or 32 indicated?
Record trouble codes.
3) If“NO”, proceed with diagnostics and repair according to trouble code indicated then perform step 29).
4) If“YES”, proceed by turning ignition switch“OFF”, disconnect battery ground cable, and wait 20 seconds. If codes 12 or 13 are
indicated proceed to step 5). If codes 12 or 13 are not indicated proceed to step 6).
5) Remove driver side airbag module and connect test harness C
connector (1C) to (AB7).
Connect airbag resistor to test harness C connector (3C). Pro-
ceed to step 19).
G5M0430
6) If codes 4 or 22 are indicated, proceed to step 7). If codes 4 or 22 are not indicated proceed to step 11).
7) Turn ignition switch“OFF”, disconnect battery ground cable,
and wait 20 seconds. Disconnect passenger side airbag mod-
ule connector (AB9) to (AB10). Connect
test harness C connector (1C) to (AB9).
Connect airbag resistor to test harness C connector (3C).
B5M0118A
8) Reconnect battery ground cable and turn ignition switch“ON”, does airbag warning light go out after 8 seconds and remain“OFF”
for more than 30 seconds? See notes 1) and 2). (Refer to end of chart.)
9) If“YES”, turn ignition switch“OFF”, disconnect battery ground cable, and wait 20 seconds. Install a new passenger side airbag
module then proceed to step 29).
10) If“NO”proceed to step 1).
11) Remove lower cover panel and connect test harness C con-
nector (1C) to (AB8) with airbag resis-
tor attached to test harness C connector (3C).
Turn ignition switch“ON”. Does airbag warning light go“OFF”
after 8 seconds and remain off for more than 30 seconds?
See notes 1) and 2). (Refer to end of chart.)
If“YES”proceed to step 5).
If“NO”proceed to step 12).
G5M0429
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

12) Turn ignition switch“OFF”, disconnect battery ground cable,
and wait 20 seconds. Connect connector (AB3) to (AB8). Dis-
connect passenger side airbag module connector (AB9) to
(AB10).
Connect test harness C connector (1C) to (AB9). Connect
airbag resistor to test harness C connector (3C).
B5M0118A
13) Reconnect battery ground cable and turn ignition switch“ON”. Does airbag warning light go“OFF”after 8 seconds and remain off
for more than 30 seconds? See notes 1) and 2). (Refer to end of chart.)
14) If“YES”, proceed to step 9).
15) If“NO”, turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Disconnect connector (AB3) to
(AB8). Connect test harness C connector (1C) to (AB8). Con-
nect airbag resistor to test harness C connector (3C).
G5M0429
16) Reconnect battery ground cable and turn ignition switch“ON”. Does airbag warning light go“OFF”after 8 seconds and remain off
for more than 30 seconds? See notes 1) and 2). (Refer to end of chart.)
17) If“YES”, turn ignition switch“OFF”, disconnect battery ground cable and wait 20 seconds. Install a new passenger side airbag
module then proceed to step 5).
18) If“NO”, proceed with diagnostics according to trouble code indicated during on-board diagnostic. Proceed to step 29).
19) Reconnect battery ground cable and turn ignition switch“ON”, does airbag warning light go out after 8 seconds and remain
“OFF”for more than 30 seconds? See notes 1) and 2). (Refer to end of chart.)
20) If“YES”, turn ignition switch“OFF”, disconnect battery ground cable and wait 20 seconds. Install driver side airbag module to 5-5 [W3B0].> and proceed to step 29).
21) If“NO”, remove lower cover panel and connect test harness
C connector (1C) to (AB8) with airbag
resistor attached to test harness C connector (3C).
Turn ignition switch“ON”. Does airbag warning light go“OFF”
after 8 seconds and remain off for more than 30 seconds?
See notes 1) and 2). (Refer to end of chart.)
If“YES”proceed to step 22).
If“NO”proceed to step 23).
G5M0429
22) If“YES”, replace combination switch, and proceed to step 26).
23) If“NO”, proceed with diagnostics and repair according to trouble code indicated, then perform step 24).
13
5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

24) Turn ignition switch“OFF”, disconnect battery ground cable,
and wait 20 seconds. Remove driver side airbag module and
connect test harness C connector (1C) to (AB7) [W3A1].> with airbag resistor attached to test harness C con-
nector (3C).
G5M0430
25) Reconnect battery ground cable and turn ignition switch“ON”. Does airbag warning light go“OFF”after 8 seconds and remain off
for more than 30 seconds? See notes 1) and 2). (Refer to end of chart.) If“YES”, proceed to step 26). If“NO”, proceed to step
27).
26) Turn ignition switch“OFF”, disconnect battery ground cable, and wait 20 seconds. Install driver side airbag module [W3B0].> and proceed to step 27).
27) Replace combination switch, and proceed to step 26).
28) Reconnect battery and turn ignition switch“ON”. Does airbag warning light go off after 8 seconds and remain off for more than 30
seconds? See notes 1) and 2). (Refer to end of chart.) If“YES”, proceed to step 29). If“NO”, proceed to step 31).
29) Perform clear memory procedure.
30) If memory cannot be cleared, another trouble code exists. Return to step 1).
31) Turn ignition switch“OFF”, disconnect battery ground cable, and wait 20 seconds. Replace driver side airbag module. 5-5 [W3A1].> Proceed to step 28).
NOTES:
1) Always remember to secure the green double locks before turning the ignition switch “ON”.
2) In some cases the airbag warning light will go “OFF” after 8 seconds but will turn “ON” again within 30 seconds. In this
case continue diagnostics with the basic diagnostics procedures or trouble code procedures.
14
5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

5. Diagnostics Chart with Trouble Code

A: TROUBLE CODE 02
DIAGNOSIS:
Front sensor harness is shorted.
Airbag main harness is shorted.
Airbag module harness (Driver or passenger) is
shorted.
Roll connector is shorted.
Airbag control module is faulty.
1. Front sensor and harness inspection
O.K.
Not O.K.
Replace front sensor.
2. Airbag main harness inspection
O.K.
Not O.K.
Replace airbag main harness.
Replace airbag control module.
CAUTION:
Before performing diagnostics on airbag system, turn
ignition switch“OFF”, disconnect battery ground ter-
minal and then wait at least 20 seconds.
After 20 seconds elapse, remove instrument panel
lower cover, and disconnect (AB3) and (AB8), (AB9)
and (AB10).


15
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code