2004 SUBARU LEGACY sensor

1-34
Seat, seatbelt and SRS airbags
Front seatbelt pretensioners
The driver’s and front passenger’s seatbelts have a
seatbelt pretensioner. The seatbelt pretensioners are
designed to be activated in the event of an accident in-
volving a moderate to severe frontal collision.
The pretensioner sensor also serves as a SRS frontal
airbag sensor. If the sensor detects a certain predeter-
mined amount of force during a frontal collision, the
front seatbelt is quickly drawn back in by the retractor
to take up the slack so that the belt more effectively re-
strains the front seat occupant.
When a seatbelt pretensioner is activated, an operat-
ing noise will be heard and a small amount of smoke
will be released. These occurrences are normal and
not harmful. This smoke does not indicate a fire in the vehicle.
Once the seatbelt pretensioner has been activated,
the seatbelt retractor remains locked. Consequently,
the seatbelt can not be pulled out and retracted and
therefore must be replaced.
NOTE y
Seatbelt pretensioners are not designed to acti-
vate in minor frontal impacts, in side or rear im-
pacts or in roll-over accidents. y The driver’s seat and passenger’s seat preten-
sioners and frontal airbag operate simultaneous- ly. y Pretensioners are designed to function on a
one-time-only basis. In the event that a preten-
sioner is activated, both the driver’s and front pas-
senger’s seatbelt retractor assemblies must be re-
placed and only by an authorized SUBARU dealer.
When replacing seatbelt retractor assemblies, use
only genuine SUBARU parts. y If either front seatbelt does not retract or cannot
be pulled out due to a malfunction or activation of
the pretensioner, contact your SUBARU dealer as
soon as possible.
HS1067BA

1-36
Seat, seatbelt and SRS airbags
the ignition key is turned to the “ON” position.
The following components are monitored by the indi- cator: y
Front sub sensor (Right hand side)
y Front sub sensor (Left hand side)
y Airbag control module (including impact sensors)
y Seatbelt pretensioner (Driver’s side)
y Seatbelt pretensioner (Passenger’s side)
y All related wiring
In the event of a malfunction indicated by any of follow-
ing, the vehicle should be taken promptly to your near-
est SUBARU dealer to have the system checked. Un-
less checked and repaired, the seatbelt pretensioners
and airbags will not function reliably:y Flashing or flickering of the indicator light.
y No illumination of the warning light when the ignition
switch is first turned to the “ON” position.y Continuous illumination of the warning light.
y Illumination of the warning light while driving.
„ System servicing
yWhen discarding a seatbelt retractor assem-
bly or scrapping the entire car damaged by a collision, consult your SUBARU dealer. y
Tampering with or disconnecting the sys-
tem’s wiring could result in accidental activa-
tion of the seatbelt pretensioner and/or airbag
or could make the system inoperative, which
may result in serious injury. The wiring har-
nesses of the seatbelt pretensioner and SRS
airbag systems are covered with yellow insula-
tion and the connectors of the system are yel-
low for easy identification. Do not use electrical
test equipment on any circuit related to the
seatbelt pretensioner and airbag systems. For
required servicing of the seatbelt pretensioner,
see your nearest SUBARU dealer.
The front sub sensors are located in both front
fenders and the airbag control module includ-
ing the impact sensors is located under the
center console. If you need service or repair in
those areas or near the front seatbelt retrac-
tors, we recommend that you have an autho-
rized SUBARU dealer perform the work.

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Seat, seatbelt and SRS airbags
– CONTINUED –
TComponents
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2
43
5
7
11
9
12
6
10
8
UB1079DB
1) Airbag control module (including
impact sensors)
2) Airbag module (driver’s side)
3) Airbag module (passenger’s
side)
4) Front sub sensor (left hand side)
5) Front sub sensor (right hand
side)
6) Seatbelt pretensioner (driver’s side)
7) Seatbelt pretensioner (passen- ger’s side)
8) Side airbag module (driver’s
side – if equipped)
9) Side airbag module (passen- ger’s side – if equipped)
10) Side airbag sensor (driver’s side)
11) Side airbag sensor (passenger’s
side)
12) Airbag wiring (yellow)

1-66
Seat, seatbelt and SRS airbags
The SRS airbag can function only when the ignition
switch is in the “ON” position.
If the front sub sensors inside the both front fenders
and the impact sensors in the airbag control module
detect a certain predetermined amount of force during
a frontal collision, the control module sends signals to
the frontal airbag modules instructing them to inflate
the SRS frontal airbags. Then both airbag modules
produce gas, which instantly inflates driver’s and pas-
senger’s SRS frontal airbags. After the deployment,
the SRS airbags immediately start to deflate so that
the driver’s vision is not obstructed. The time required
from detecting impact to the deflation of the SRS air-
bag after deployment is shorter than the blink of aneye.
The front passenger’s SRS frontal airbag deploys to-
gether with driver’s SRS frontal airbag even when no
one occupies the front passenger’s seat.
When the SRS frontal airbags deploy, the driver’s and
front passenger’s seatbelt pretensioners operate at
the same time.
Although it is highly unlikely that the SRS airbag would
activate in a non-accident situation, should it occur,
the SRS airbag will deflate quickly, not obscuring vi-
sion and will not interfere with the driver’s ability to
maintain control of the vehicle.
When the SRS airbag deploys, a sudden, fairly loud
inflation noise will be heard and some smoke will be
released. These occurrences are normal result of the
deployment. This smoke does not indicate a fire in thevehicle.
Do not touch the SRS airbag system compo-
nents around the steering wheel and dash-
board with bare hands right after deployment.
Doing so can cause burns because the compo-
nents can be very hot as a result of deployment.
The SRS frontal airbag is designed to deploy in the
event of an accident involving a moderate to severe
frontal collision. It is basically not designed to deploy
in lesser frontal impacts because the necessary pro-
tection can be achieved by the seatbelt alone. Also, it
is basically not designed to deploy in side or rear im-
pacts or in roll-over accidents because deployment of
the SRS frontal airbag would not help the occupant in
those situations. The SRS airbag is designed to func-
tion on a one-time-only basis.
SRS airbag deployment depends on the level of force

1-74
Seat, seatbelt and SRS airbags
T
Operation
A) SRS side airbag deploys as soon as a collision oc- curs.
B) After deployment, SRS side airbag starts to deflate im- mediately. The SRS side airbag can function only when the igni-
tion switch is in the “ON” position.
The driver’s and front passenger’s SRS side airbags
deploy independently of each other since each has its
own impact sensor. Also, the SRS side airbag deploys
independently of the frontal airbags in the steering
wheel and instrument panel.
An impact sensor is incorporated into each of the ve-
hicle’s center pillars. If either sensor detects a certain
predetermined amount of force during a side impact
collision, the control module sends a signal to the side
airbag module on the impacted side of the vehicle, in-
structing it to inflate the SRS side airbag. Then the
side airbag module produces gas, which instantly in-
flates the SRS side airbag. After the deployment, the
SRS side airbag immediately starts to deflate. The
time required from detecting impact to the deflation of
the SRS side airbag after deployment is shorter than
the blink of an eye.
The SRS side airbag deploys even when no one occu-
pies the seat on the side of which an impact is applied.
When the SRS side airbag deploys, a sudden, fairly
loud inflation noise will be heard and some smoke will
be released. These occurrences are normal result of
the deployment. This smoke does not indicate a fire in
A B
UB0359

1-79
Seat, seatbelt and SRS airbags
– CONTINUED –
cator: yFront sub sensor (Right hand side)
y Front sub sensor (Left hand side)
y Airbag control module (including impact sensors)
y Frontal airbag module (Driver’s side)
y Frontal airbag module (Passenger’s side)
y Side airbag sensor (Driver’s side – if equipped)
y Side airbag sensor (Passenger’s side – if equipped)
y Side airbag module (Driver’s side – if equipped)
y Side airbag module (Passenger’s side – if
equipped)y Seatbelt pretensioner (Driver’s side)
y Seatbelt pretensioner (Passenger’s side)
y All related wiring
In the event of a malfunction indicated by any of follow-
ing, the vehicle should be taken promptly to your near-
est SUBARU dealer to have the system checked. Un-
less checked and repaired, the SRS airbags will not
function reliably: y Flashing or flickering of the indicator light.
y No illumination of the warning light when the ignition
switch is first turned to the “ON” position.y Continuous illumination of the warning light.
y Illumination of the warning light while driving. „
SRS airbag system servicing
yWhen discarding an airbag module or scrap-
ping the entire car damaged by a collision, con-
sult your SUBARU dealer. y The SRS airbag has no user-serviceable
parts. Do not use electrical test equipment on
any circuit related to the SRS airbag system.
For required servicing of the SRS airbag, see
your nearest SUBARU dealer. Tampering with
or disconnecting the system’s wiring could re-
sult in accidental inflation of the SRS airbag or
could make the system inoperative, which may
result in serious injury. The wiring harnesses of
the SRS airbag system are covered with yellow
insulation and system connectors are yellow
for easy identification.
If you need service or repair in areas listed be-
low, we recommend that you have an autho-
rized SUBARU dealer perform the work. The
SRS airbag control module, impact sensors
and airbag modules are stored in these areas.

2-15
Keys and doors
– CONTINUED –
Security system (if equipped)
The security system helps to protect your vehicle and
valuables from theft. The horn sounds and the turn
signal lights flash if someone attempts to break into
your vehicle. The starter motor is also interrupted to
prevent starting the vehicle without a key.
The system can be armed and disarmed with the re-
mote transmitter.
The system does not operate when the key is inserted
into the ignition switch. „System operation
The security system will give the following alarm indi-
cations when triggered: y The turn signal lights will flash and the horn will
sound intermittently. In addition, the starter motor will
not operate. y The alarm automatically resets after 30 seconds;
however, the alarm will reactivate if the vehicle is tam-
pered with again. The alarm will continue for six times
if any sensor continues to be activated.
The alarm is triggered by: y Opening a door, the rear gate or trunk lid.
y Application of physical shock to the vehicle (e.g. breaking glass or forced entry). Note that there are two
alarm levels for shock: warning and alarm. In warning
mode, the alarm detects lower level vibrations and
triggers 2 warning chirps on the horn and two flashes
on the lights as a deterrent to would be vandals. In
alarm mode, higher levels of shock are detected and
the system will go into full alarm. y
Ignition switch being turned on while in armed state.
NOTE
With the valet mode selected, the security system
does not operate and the parking lights do not
flash when the remote transmitter is used for lock-
ing and unlocking.
The security system indicator light in the combi-
nation meter flashes twice per second to show
that the valet mode is selected.
For details, refer to “Valet mode” in this section. „ Arming the system
T To arm the system using remote transmitter
1. Close all windows and moonroofs (if so equipped).
2. Remove the key from the ignition switch.
3. Open the doors and get out of the vehicle.
4. Make sure that the engine hood (and the trunk lid)
are locked.

2-21
Keys and doors
– CONTINUED –
3. Open the doors and get out of the vehicle.
4. Before closing the doors, lock all doors with the in-
side door lock levers.
5. Close the doors. The system will automatically arm
after one minute.
In the passive mode, the system can also be armed
with the remote transmitter or with the power door
locking switches. If the remote transmitter or power
door lock switch is used to lock the vehicle, arming will
take place immediately regardless of whether or not
the passive mode has been selected. TDisarming the system
To disarm the system, briefly press the “UNLOCK/ DISARM” button on the transmitter.T
Tripped sensor identification
If an electronic chirp sounds four times and the turn
signal lights flash four times when you disarm the sys-
tem, this indicates that the alarm was triggered. The
number of times the indicator light flashes indicates
what sensor caused the alarm condition.
To enter identification mode:
1. Open the driver’s door and leave it open.
2. Turn the ignition switch to the “ON” position two times. (“LOCK” “ON” “LOCK” “ON”
“LOCK”)
3. The indicator light will start flashing.
The indicator light provides the following indications.
Flashing one time: Any door, the rear gate or the
trunk lid has been opened.
Flashing three times: The impact sensor in the sys-
tem’s unit has been activated. This may indicate that
your vehicle has been shocked or tampered with by
some outside force and/or unauthorized person.
Flashing four times: The ignition switch has been
turned on or the battery has been disconnected.
NOTE
The battery must be reconnected before the indi-
cator light will flash.
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UB2024DB