1997 SUBARU LEGACY sensor

4. Diagnostics Chart for On-board
Diagnostic System
A: BASIC DIAGNOSTICS PROCEDURE
1) Airbag warning light comes “ON”.
2) Turn ignition switch to “ON”, (engine “OFF”) and observe airbag warning light.
3) If airbag warning light stays “ON” after about 7 seconds or remains “OFF”, or comes back “ON” after 30 seconds, this indicates a
current problem. Proceed to step 8).
If airbag warning light comes “ON” for about 7 seconds, then goes out and stays out, this indicates normal system operation at this
time. Check the memory for intermittent problems by performing the procedure outlined in 5-5b [T4B0] “ON-BOARD DIAGNOSTICS”.
Proceed to step 4).
4) If trouble code indicated, proceed to step 5).
If normal code indicated, proceed to step 6).
5) Repair and replacement, proceed to step 7).
6) Repair and replacement, proceed to step 7).
7) Turn ignition switch “ON”, (engine “OFF”) and observe airbag warning light. If airbag warning light stays “ON” after about 7 seconds
or comes back “ON” after 30 seconds, proceed to step 8).
If airbag warning light comes “ON” for about 7 seconds, then goes out and stays out, proceed to step 9).
8) Repair and replacement. Proceed to step 10).
9) Clear memory. Proceed to step 10).
10) END
B5M0115B
B: ON-BOARD DIAGNOSTIC
When the airbag system is in functioning condition, the
airbag warning light will remain on for about 7 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.
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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
4. Diagnostics Chart for On-board Diagnostic System

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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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
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
04 Provided.1) Airbag main harness circuit is shorted.
2) Airbag module harness (Ps) circuit is shorted.
3) Airbag control module is faulty.16
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.17
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.20
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.21
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) (AB6) is not connected properly to airbag control
module.22
21 Provided. Airbag control module is faulty. 24
22 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Ps) circuit is open.
3) Airbag control module is faulty.25
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.26
33 Provided. Airbag module is inflated. 28
34 Provided.1) Airbag main harness circuit (Ps) is shorted to
power supply.
2) Airbag module harness (Ps) is shorted to power
supply.
3) Airbag control module is faulty.29
41 Provided.1) Airbag main harness circuit (Dr) is shorted to
ground.
2) Airbag module harness circuit (Dr) is shorted to
ground.
3) Roll connector circuit is shorted to ground.
4) Airbag control module is faulty.30
42 Provided.1) Airbag main harness circuit (Ps) is shorted to
ground.
2) Airbag module harness circuit (Ps) is shorted to
ground.
3) Airbag control module is faulty.31
43 Provided.1) Airbag main harness circuit (Dr) is shorted to
power supply.
2) Airbag module harness (Dr) is shorted to power
supply.
3) Roll connector is shorted to power supply.
4) Airbag control module is faulty.32
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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
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 (B39) are not connected properly.33
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.36
Warning light indicates trouble code,
then normal code. (Flashing trouble
code.)Provided. Airbag system component parts are faulty. 38
Warning light indicates trouble code,
then normal code. (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.41
[NOTE] Dr: Driver side Ps: Passenger side
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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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
4. Diagnostics Chart for On-board Diagnostic System

E: DIAGNOSTICS PROCEDURE
1. AIRBAG WARNING LIGHT STAYS ON AFTER
ABOUT 7 SECONDS.
1) Perform on-board diagnostic.
2) Are trouble codes 4, 12, 13, 22, 34, 41, 42 or 43 indi-
cated?
Record trouble codes. If“YES”proceed to step 4). If“NO”
proceed to step 3).
3) Proceed with diagnostics and repair according to
trouble code indicated then perform step 15).
4) If codes 4, 22, 34, 42 are indicated, proceed to step 5).
If codes 4, 22, 34, 42 are not indicated, proceed to step
10).
5) If codes 12, 13, 41, 43 are indicated, proceed to step 6).
If codes 12, 13, 41, 43 are not indicated, proceed to step
11).
G5M0589
G5M0429
6) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Disconnect passenger side
airbag module connector (AB9) to (AB10). [W3A2].> Connect test harness C connector (1C) to (AB9).
Connect airbag resistor to test harness C connector (3C).
Remove lower cover panel and connect test harness C
connector (1C) to (AB8) with airbag
resistor attached to test harness C connector (3C).
Connect battery ground cable and turn ignition switch
“ON”. Does airbag warning light go“OFF”after about 7
seconds and remain off for more than 30 seconds?
See“NOTE:”.
If“YES”proceed to step 7).
If“NO”proceed to step 3).
G5M0429
7) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Connect passenger side air-
bag module connector (AB9) to (AB10). Connect battery
ground cable and turn ignition switch“ON”. Does airbag
warning light go“OFF”after about 7 seconds and remain
off for more than 30 seconds?
See“NOTE:”.
If“YES”proceed to step 8).
If“NO”proceed to step 13).
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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
4. Diagnostics Chart for On-board Diagnostic System

G5M0430
8) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Connect connector (AB8) to
(AB3). Remove driver side airbag module and connect test
harness C connector (1C) to (AB7).
Connect airbag resistor to test harness C connector (3C).
Connect battery ground cable and turn ignition switch
“ON”. Does airbag warning light go“OFF”after about 7
seconds and remain off for more than 30 seconds?
See“NOTE:”.
If“YES”proceed to step 9).
If“NO”proceed to step 14).
9) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Replace with a new driver side
airbag module. Proceed to step
15).
G5M0429
10) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Remove lower cover panel
and connect test harness C connector (1C) to (AB8) to 5-4 [W1A0].> with airbag resistor attached to test har-
ness C connector (3C).
Connect battery ground cable and turn ignition switch
“ON”. Does airbag warning light go“OFF”after about 7
seconds and remain off for more than 30 seconds?
See“NOTE:”.
If“YES”proceed to step 8).
If“NO”proceed to step 3).
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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
4. Diagnostics Chart for On-board Diagnostic System

G5M0589
11) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Disconnect passenger side
airbag module connector (AB9) to (AB10). [W3A2].>
Connect test harness C connector (1C) to (AB9). Connect
airbag resistor to test harness C connector (3C).
Connect battery ground cable and turn ignition switch
“ON”. Does airbag warning light go“OFF”after about 7
seconds and remain off for more than 30 seconds?
See“NOTE:”.
If“YES”proceed to step 12).
If“NO”proceed to step 3).
12) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Replace with a new passen-
ger side airbag module then pro-
ceed to step 15).
13) Turn ignition switch“OFF”, disconnect battery ground
cable and wait 20 seconds. Replace with a new passenger
side airbag module then proceed
to step 7).
14) Turn ignition switch“OFF”, disconnect battery ground
cable, and wait 20 seconds. Replace with a new combina-
tion switch, and install driver side
airbag module .
Connect battery ground cable and turn ignition switch
“ON”. Does airbag warning light go“OFF”after about 7
seconds and remain off for more than 30 seconds?
See“NOTE:”.
If“YES”proceed to step 16).
If“NO”proceed to step 9).
15) Connect battery ground cable and turn ignition switch
“ON”. Does airbag warning light go“OFF”after about 7
seconds and remain off for more than 30 seconds? See
“NOTE:”.
If“YES”proceed to step 16).
If“NO”proceed to step 1).
16) Perform clear memory procedure. [T4C0].>
If memory cannot be cleared, another trouble code exists.
Return to step 1).
If memory can be cleared, proceed to step 17).
17) END
NOTE:
Always remember to secure the green double locks
before turning the ignition switch“ON”.
In some cases the airbag warning light will go“OFF”
after about 7 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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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
4. Diagnostics Chart for On-board Diagnostic System

5. Diagnostics Chart with Trouble Code

A: 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
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.
: Connector & terminal
(5B) No. 6 — (5B) No. 7:
Is resistance more than 10 kΩ?
: Replace airbag control module.
: Replace airbag main harness.
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5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
5. Diagnostics Chart with Trouble Code