SUBARU LEGACY 1996 Service Repair Manual

B5M0115B
B: ON-BOARD DIAGNOSTIC
When the airbag system is in functioning condition, the
airbag warning light will remain on for 8 seconds and go out
when the ignition switch is set to ON.
If there is any malfunction, the airbag warning light will
either stay on or off continuously. In such cases, perform
on-board diagnostic in accordance with the specified pro-
cedure to determine trouble codes.
1) Turn ignition switch ON (with engine OFF).
2) Connect DIAG. terminal

1to No. 1 terminal of diagno-
sis connector

2located below lower cover.
3) Check in accordance with the trouble code indicated by
the AIRBAG warning light, and record the trouble codes.
4) Turn the ignition switch “OFF” and remove the DIAG.
terminal from No.1 terminal of diagnosis connector.
B5M0116B
C: CLEAR MEMORY
After eliminating problem as per trouble code, clear
memory as follows:
Make sure ignition switch is ON (and engine off). Connect
one DIAG. terminal

1on diagnosis connector
2terminal
No. 1.
While warning light is flashing, connect the other DIAG.
terminal

3on terminal No. 2 for at least three seconds.
After memory is cleared, normal warning light flashing rate
resumes. (Warning light flashes every 0.6 seconds ON-
OFF operation.) Memory cannot be cleared if any problem
exists.
After clear memory and then DIAG. terminals

1and
3,
extract from diagnosis connector

2.
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

D: LIST OF TROUBLE CODES
1. TROUBLE CODES
Trouble code/Contents of troubles Memory function Contents of diagnosis Page
02 Provided.1) Front sensor harness is shorted.
2) Airbag main harness is shorted.
3) Airbag module harness (Dr/Ps) is shorted.
4) Roll connector is shorted.
5) Airbag control module is faulty.16
03 Provided.1) Front sensor harness circuit is open.
2) Front sensor unit circuit is open.18
04 Provided.1) Airbag main harness circuit is shorted.
2) Airbag module harness (Ps) circuit is shorted.
3) Airbag control module is faulty.19
11 Provided.1) Airbag control module is faulty.
2) Airbag main harness circuit is open.
3) Fuse No. 8 is blown.
4) Body harness circuit is open.20
12 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Dr) circuit is open.
3) Roll connector circuit is open.
4) Airbag control module is faulty.22
13 Provided.1) Airbag main harness circuit is shorted.
2) Airbag module harness (Dr) is shorted.
3) Roll connector circuit is shorted.
4) Airbag control module is faulty.23
14 Not provided.1) (AB9) and (AB10) are not connected properly.
2) (AB2) and (AB7) are not connected properly.
3) (AB3) and (AB8) are not connected properly.
4) (AB4), (AB5) and (AB6) are not connected
properly to airbag control module.24
21 Provided. Airbag control module is faulty. 26
22 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Ps) circuit is open.
3) Airbag control module is faulty.27
23 Provided.1) Airbag main harness is shorted to power supply.
2) Front sensor harness is shorted to power supply.
3) Airbag module harness (Dr/Ps) is damaged.
4) Roll connector is shorted to power supply.
5) Airbag control module is faulty.28
24 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Dr) circuit is open.
3) Roll connector circuit is open.
4) Airbag control module is faulty.
5) Above diagnosis plus other faulty of airbag
modular parts.30
31 Not provided.1) Airbag control module is faulty.
2) Airbag main harness circuit is open.
3) Fuse No. 16 is blown.
4) Body harness circuit is open.32
32 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Ps) circuit is open.
3) Airbag control module is faulty.
4) Above diagnosis plus other faulty of airbag
modular parts.34
NOTE: Dr: Driver side Ps: Passenger side
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

Trouble code/Contents of troubles Memory function Contents of diagnosis Page
Airbag warning light remains on. Not provided.1) Airbag warning light is faulty.
2) Airbag control module to airbag warning light
harness circuit is shorted or open.
3) Grounding circuit is faulty.
4) Airbag control module is faulty.
5) (AB1) and (B31) are not connected properly.36
Airbag warning light remains off. Not provided.1) Fuse No. 15 is blown.
2) Body harness circuit is open.
3) Airbag warning light is faulty.
4) Airbag main harness is faulty.
5) Airbag control module is faulty.40
Warning light
indicates trouble
code, then normal
code.Flashing trouble
code.Provided. Airbag system component parts are faulty. 42
Flashing
normal code.
Not provided.1) Airbag connector is faulty.
2) Fuse No. 16 is blown.
3) Airbag main harness is faulty.
4) Airbag control module is faulty.
5) Body harness is faulty.45
2. HOW TO READ TROUBLE CODES
The AIRBAG warning light flashes a code corresponding to
the faulty parts.
The long segment (1.2 sec on) indicates a“ten”, and the
short segment (0.3 sec on) indicates a“one”.
B5M0117A
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

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).
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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.
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

G5M0558
1. FRONT SENSOR AND HARNESS INSPECTION
1) Disconnect connectors (AB4) and (AB5) from airbag
control module.
2) Connect connectors (AB4) and (AB5) to connector (8B)
of test harness B2.
3) Measure resistance between connector (5B) terminal
indicated.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17 — No. 18 / 1.4 — 1.6 kΩ
(LH: AB5): No. 15 — No. 16 / 1.4 — 1.6 kΩ
4) Measure resistance between each connector (5B) ter-
minal and body.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17 — Body/1MΩ, or more
No.18—Body/1MΩ, or more
(LH: AB5): No. 15 — Body/1MΩ, or more
No.16—Body/1MΩ, or more
G5M0559
2. AIRBAG MAIN HARNESS INSPECTION
1) Disconnect connector (AB6) from airbag control module
, and connect (AB6) to test harness
B2 connector (8B).
2) Measure resistance between each (5B) terminal and
body.
(5B) Terminal / Specified resistance:
No.1—Body/1MΩ, or more
No.14—Body/1MΩ, or more
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

B: TROUBLE CODE 03
DIAGNOSIS:
Front sensor harness circuit is open.
Front sensor unit circuit is open.
1. Front sensor (LH and RH) inspectionIdentify faulty sensor and replace front sensor.
CAUTION:
Before performing the diagnostics on airbag system,
turn ignition switch“OFF”, disconnect battery ground
terminal and then wait at least 20 seconds.
G5M0558
1. FRONT SENSOR (LH AND RH) INSPECTION
1) Disconnect connectors (AB4) and (AB5) from airbag
control module.
2) Connect connectors (AB4) and (AB5) to test harness
B2 connector (8B).
3) Measure resistance between connector (5B) terminal.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17—No. 18 / 1.4—1.6 kΩ
(LH: AB5): No. 15—No. 16 / 1.4—1.6 kΩ
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5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

C: TROUBLE CODE 04
DIAGNOSIS:
Airbag main harness circuit is shorted.
Airbag module harness (Passenger) circuit is shorted.
Airbag control module is faulty.
1. 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
cable and then wait at least 20 seconds.
After 20 seconds elapse, remove instrument panel
lower cover, and disconnect (AB3) and (AB8), (AB9)
and (AB10).
G5M0559
1. AIRBAG MAIN HARNESS INSPECTION
1) Disconnect connector (AB6) from airbag control module
, and connect it to test harness B2
connector (8B).
2) Measure resistance between test harness B2 connec-
tor (5B) terminal.
(5B) Terminal / Specified resistance:
No. 6—No.7/10kΩ, or more

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

D: TROUBLE CODE 11
DIAGNOSIS:
Airbag control module is faulty.
Airbag main harness circuit is open.
Fuse No. 8 is blown.
Body harness circuit is open.
1. Airbag control module inspection
Not O.K.
O.K.
Replace airbag control module.
2. Airbag main harness inspection
O.K.
Not O.K.
Replace airbag main harness.
3. Fuse No. 8 inspection
O.K.
Not O.K.
Replace fuse No. 8.
Repair body harness.
CAUTION:
Before performing diagnostics on airbag system, turn
ignition switch“OFF”, disconnect battery ground
cable and then wait at least 20 seconds.
After 20 seconds elapse, remove instrument panel
lower cover, and disconnect (AB3) and (AB8), (AB9)
and (AB10).
G5M0559
1. AIRBAG CONTROL MODULE INSPECTION
1) Disconnect connector (AB6) from airbag control module
and connect it to test harness B2
connector (8B).
2) Connect battery ground cable and turn ignition switch
“ON”. (engine off)
3) Measure voltage across connector (5B) terminal and
body.
(5B) Terminal / Specified voltage:
No. 2—Body / 10 V, or more
2. AIRBAG MAIN HARNESS INSPECTION
1) Go to step 2) below after performing diagnostics on air-
bag system as per flowchart under“1. AIRBAG CON-
TROL MODULE INSPECTION”previously outlined.
2) Turn ignition switch“OFF”, disconnect battery ground
terminal and then wait at least 20 seconds.



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