1997 SUBARU LEGACY light

O: AIRBAG WARNING LIGHT REMAINS OFF.
DIAGNOSIS:
Fuse No. 15 is blown.
Body harness circuit is open.
Airbag warning light is faulty.
Airbag main harness is faulty.
Airbag control module is faulty.
1. Fuse No. 15 inspection
2. Body harness inspection
3. Airbag warning light module (in combination
meter) inspection
4. Airbag main harness inspection
CAUTION:
Before performing diagnostics on airbag system, turn
ignition switch“OFF”, disconnect battery ground
terminal, and then wait at least 20 seconds.
G5M0460
1. FUSE No. 15 INSPECTION
Remove and visually check fuse No. 15.
: Is fuse No. 15 blown?
: Replace fuse No. 15.
If fuse No. 15 blows again, go to step2.
: Go to step2.
2. BODY HARNESS INSPECTION
Turn ignition switch“ON”(engine off) to make sure other
warning lights (in combination meter) illuminate.
: Do all the warning lights (in combination
meter) except airbag warning light come
on?
: Go to step3.
: Repair body harness.



36
5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
5. Diagnostics Chart with Trouble Code

B5M0122B
3. AIRBAG WARNING LIGHT MODULE (IN
COMBINATION METER) INSPECTION
1) Turn ignition switch“OFF”, disconnect battery ground
cable and then wait at least 20 seconds.
2) Disconnect body harness connector (B31) from connec-
tor (AB1).
B5M0124A
3) Connect battery ground cable and turn ignition switch
“ON”(engine off) to make sure airbag warning light illumi-
nates.
: Does the airbag warning light come on?
: Go to step4.
: Replace airbag warning light module
1.
G5M0312
4. AIRBAG MAIN HARNESS INSPECTION
1) Turn ignition switch“OFF”, disconnect battery ground
cable and then wait at least 20 seconds.
2) Connect body harness connector (B31) and connector
(AB1).
3) Disconnect connectors (AB3) and (AB8) below steering
column.
G5M0313
4) Disconnect connector (AB6) from airbag control mod-
ule.
5) Connect battery ground cable and turn ignition switch
“ON”to make sure airbag warning light illuminates.
: Does the airbag warning light come on?
: Replace airbag control module.
: Replace airbag main harness.
37
5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
5. Diagnostics Chart with Trouble Code

P: WARNING LIGHT INDICATES TROUBLE
CODE, THEN NORMAL CODE.
—FLASHING TROUBLE CODE.—
DIAGNOSIS:
Airbag system component parts are faulty.
1. Airbag component parts appearance
inspection
2. Airbag component parts vibration inspection
3. Showering inspection to body
CAUTION:
Before performing diagnostics on airbag system, turn
ignition switch“OFF”, disconnect battery ground
cable, and then wait at least 20 seconds.


38
5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
5. Diagnostics Chart with Trouble Code

Q: WARNING LIGHT INDICATES TROUBLE
CODE, THEN NORMAL CODE.
—FLASHING NORMAL CODE.—
DIAGNOSIS:
Airbag connector is faulty.
Fuse No. 16 is blown.
Airbag main harness is faulty.
Airbag control module is faulty.
Body harness is faulty.
1. Airbag connector appearance inspection
2. Airbag connector vibration inspection
3. Showering inspection to body
4. Fuse No. 16, airbag main harness, airbag
control module, body harness appearance
inspection
5. Fuse No. 16, airbag main harness, body
harness vibration inspection
6. Showering inspection to body
7. Warning light illumination check
CAUTION:
Before performing diagnostics on airbag system, turn
ignition switch“OFF”, disconnect battery ground
cable, and then wait at least 20 seconds.
1. AIRBAG CONNECTOR APPEARANCE INSPECTION
Conduct appearance inspection on airbag connectors
(AB2) through (AB8).
: Is there anything unusual about the appear-
ance of connectors (AB2) through (AB8)?
: Replace faulty airbag component parts.
: Go to step2.
NOTE:
Check terminals, case and wiring harnesses for damage.






41
5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
5. Diagnostics Chart with Trouble Code

5. FUSE No. 16, AIRBAG MAIN HARNESS, BODY
HARNESS VIBRATION INSPECTION
Conduct vibration inspection on fuse No. 16, airbag main
harness and body harness.
CAUTION:
Do not shake or vibrate airbag control module.
: Do fuse No. 16, airbag main harness or body
harness malfunction again when shaking?
: Replace faulty airbag component parts.
: Go to step6.
NOTE:
Gently shake each part.
G5M0461
6. SHOWERING INSPECTION TO BODY
Spray water on vehicle body.
CAUTION:
Do not directly spray water on each part.
: Does water leak into the passenger com-
partment when showering vehicle?
: Replace faulty airbag component parts.
: Go to step7.
NOTE:
If leaks are noted, check wiring harnesses as water may
leak along them and get parts wet.
7. WARNING LIGHT ILLUMINATION CHECK
Turn ignition switch“ON”(engine off) and observe airbag
warning light.
: Does the airbag warning light comes on for
about 7 seconds, then go out and stay out?
: Clear memory.
:Goto“DIAGNOSTICS PROCEDURE”.

43
5-5bSUPPLEMENTAL RESTRAINT SYSTEM (ELECTRIC SENSOR TYPE)
5. Diagnostics Chart with Trouble Code

5. Control Module I/O Signal
G6M0015
ContentTerminal
No.Measuring conditions and I/O signals (ignition switch ON and engine idling)
Main power supply 2
Battery voltage is present when main power is turned ON.

“0”volt is present when main power is turned OFF.
Inhibitor switch (AT) (U.S.A.)
N position switch (AT) (CANADA)4
“0”volt is present when selector lever is set to P or N position (CANADA: N position only).

Battery voltage is present when selector lever is other than P or N position (CANADA: N
position only).
Air valve 5
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
GND 6—
Vacuum pump motor 7
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
Data link connector 8—
RESUME/ACCEL switch 9
Battery voltage is present when switch is turned ON.

“0”volt is present when switch is turned OFF.
SET/COAST switch 10
Battery voltage is present when switch is turned ON.

“0”volt is present when switch is turned OFF.
Ignition switch 12
Battery voltage is present when ignition switch is turned ON.

“0”volt is present when ignition switch is turned OFF.
Release valve 13
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
Power supply to vacuum pump
motor, air valve, release valve14
“0”volt is present when vehicle is stopped.

Battery voltage is present while cruise control is operating.
Cruise main switch 15
Battery voltage is present during pressing the main switch, and then approx. 12 V is
present while switch is turned ON.

“0”volt is present when switch is turned OFF.
Brake switch 16Turn the cruise main switch to ON and leave clutch pedal released (MT).
Then check that;

“0”volt is present when brake pedal is depressed.

Battery voltage is present when brake pedal is released.
Additionally only in MT vehicle, keep the cruise main switch to ON and leave brake pedal
released.
Then check that;

“0”volt is present when clutch pedal is depressed.

Battery voltage is present when clutch pedal is released.
Data link connector 17—
Data link connector 18—
Vehicle speed sensor 2 19Lift-up the vehicle until all four wheels are raised off ground, and then rotate any wheel manu-
ally.
Approx. 5 and 0 volt pulse signals are alternately input to cruise control module.
Stop light switch 20Turn ignition switch to OFF.
Then check that;

Battery voltage is present when brake pedal is depressed.

“0”volt is present when brake pedal is released.
NOTE:
Voltage at terminals 5, 7, 13 and 14 cannot be checked unless vehicle is driving by cruise control operation.
7
6-2BODY ELECTRICAL SYSTEM
5. Control Module I/O Signal

7. Diagnostics Chart for Power Line
A: BASIC DIAGNOSTICS PROCEDURE
Drive at cruise speed.
Cruise speed can be set.
(Cruise control is available.)Cruise speed cannot be set.
(Cruise control is not available.)
Check cruise control main switch
light and circuit.
Check cruise control main
switch circuit.
OK
Not OK
Repair.
Check cruise control main
switch.
OK
Not OK
Repair.
Faulty cruise control module.



11
6-2BODY ELECTRICAL SYSTEM
7. Diagnostics Chart for Power Line

B: CHECK INDICATOR AND CIRCUIT IN
CRUISE CONTROL MAIN SWITCH
DIAGNOSIS:

Bulb failure or open harness of the indicator circuit in the
cruise control main switch.
TROUBLE SYMPTOM:

Cruise control can be set, normally indicator does not
come on. (When main switch is pressed.)
1. Check cruise control main switch.
OK
Not OK
Replace bulb.
2. Check circuit between cruise control module
and cruise control main switch indicator light.
OK
Not OK

Repair or replace wiring harness.

If no output from the cruise control module,
replace the cruise control module.
Failure of the cruise control module.
B6M0275


12
6-2BODY ELECTRICAL SYSTEM
7. Diagnostics Chart for Power Line