2003 SUBARU IMPREZA sensor

Seat, seatbelt and SRS airbags
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Seatbelt maintenance
To clean the seatbelts, use a mild soap and luke-
warm water. Never bleach or dye the belts because
this could seriously affect their strength. Inspect the seatbelts and attachments including the
webbing and all hardware periodically for cracks,
cuts, gashes, tears, damage, loose bolts or worn
areas. Replace the seatbelts even if only minor dam- age is found.
CAUTION
Keep the belts free of polishes, oils, chemi-
cals and particularly battery acid. Never attempt to make modifications or
changes that will prevent the seatbelt from op-
erating properly. 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
involving a moderate to severe frontal collision.
The pretensioner sensor also serves as the frontal
SRS airbag sensor. If the sensor detects a certain
predetermined amount of force during a frontal colli-
sion, the front seatbelt is quickly drawn back in by
the retractor to take up the slack so that the belt
more effectively restrains the front seat occupant.
When a seatbelt pretensioner is activated, an oper-

Seat, seatbelt and SRS airbags
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System monitors
A diagnostic system continually monitors the readi-
ness of the seatbelt pretensioner while the vehicle is
being driven. The seatbelt pretensioners share the
control module with the SRS airbag system. There-
fore, if any malfunction occurs in a seatbelt preten-
sioner, the SRS airbag system warning light will illu-
minate. The SRS airbag system warning light will
show normal system operation by lighting for about
6 seconds when the ignition key is turned to the
“ON” position.
The following components are monitored by the indi- cator:
Front sub sensor (Right hand side)
Front sub sensor (Left hand side)
Airbag control module (including impact sensors)
Seatbelt pretensioner (driver ’s side)
Seatbelt pretensioner (Passenger ’s side)
All related wiring
In the event of a malfunction indicated by any of fol-
lowing, the vehicle should be taken promptly to your
nearest SUBARU dealer to have the system
checked. Unless checked and repaired, the seatbelt
pretensioners and SRS airbag will not function reli- ably: Flashing or flickering of the indicator light.
No illumination of the warning light when the igni-
tion switch is first turned to the “ON” position.
Continuous illumination of the warning light.
Illumination of the warning light while driving.
System servicing
WARNING
When discarding a seatbelt retractor assem-
bly or scrapping the entire car damaged by a
collision, consult your SUBARU dealer. Tampering with or disconnecting the sys-
tem’ s wiring could result in accidental activa-

Seat, seatbelt and SRS airbags
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tion of the seatbelt pretensioner and/or SRS airbag or could make the system inoperative,
which may result in serious injury. The wiring
harnesses of the seatbelt pretensioner and
SRS airbag systems are covered with yellowinsulation and the connectors of the system are yellow for easy identification. Do not use
electrical test equipment on any circuit relatedto the seatbelt pretensioner and SRS airbag
systems. For required servicing of the seat-
belt pretensioner, see your nearest SUBARU
dealer.
CAUTION
The front sub sensors are located in both front fenders and the SRS airbag control mod-
ule including the impact sensors is located
under the center console. If you need service or repair in those areas or near the front seat-belt retractors, we recommend that you have
an authorized SUBARU dealer perform thework.
NOTE If the front part of the vehicle is damaged in an
accident to the extent that the seatbelt preten- sioner does not operate, contact your SUBARUdealer as soon as possible.
Precautions against vehicle modifica- tion
CAUTION
Do not perform any of the following modifica- tions. Such modifications can interfere with proper operation of the seatbelt pretension- ers.Attachment of any equipment (bush bar,
winches, snow plow, skid plate, etc.) otherthan SUBARU genuine accessory parts to thefront end. Modification of the suspension system or
front end structure. Installation of a tire of different size and
construction from the tires specified on thetire placard attached to the driver ’s door jamb.
Always consult your SUBARU dealer if you want to
install any accessory parts to your vehicle.

Seat, seatbelt and SRS airbags
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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) Side airbag module
(driver’ s side — if equipped)
7) Side airbag module (passenger’ s side — if
equipped)
8) Side airbag sensor (driver ’s
side — if equipped)
9) Side airbag sensor (passenger’ s side — if
equipped)
10) Airbag wiring (yellow)
11) Seatbelt pretensioner (driver ’s
side)
12) Seatbelt pretensioner (passenger’ s side)

Seat, seatbelt and SRS airbags
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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 dur-
ing a frontal collision, the control module sends sig-
nals to the frontal airbag modules instructing them to
inflate the SRS frontal airbags. Then both airbag
modules produce gas, which instantly inflates driv-er’ s and passenger ’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 airbag after deployment is
shorter than the blink of an eye.
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.
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 ob-
scuring vision 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 firein the vehicle.
CAUTION
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 com-ponents can be very hot as a result of deploy-ment.
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 neces-
sary protection can be achieved by the seatbelt
alone. Also, it is basically not designed to deploy in
side or rear impacts or in roll-over accidents be-
cause deployment of the SRS frontal airbag wouldnot help the occupant in those situations. The SRS
airbag is designed to function on a one-time-onlybasis.
SRS airbag deployment depends on the level of
force experienced in the passenger compartment
during a collision. That level differs from one type of

Seat, seatbelt and SRS airbags
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Operation
A) SRS side airbag deploys as soon as a collision
occurs.
B) After deployment, SRS side airbag starts to deflate immediately. The SRS side airbag can function only when the
ignition 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 de-
ploys independently of the frontal airbags in the steering wheel and instrument panel.
An impact sensor is incorporated into each of the
vehicle’ 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, instructing it to inflate the SRS side air-
bag. Then the side airbag module produces gas,which instantly inflates 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 oc- cupies the seat on the side on which an impact isapplied.
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 re-

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The SRS side airbag is basically not designed to
deploy if the vehicle is involved in a frontal collision
or is struck from behind. Examples of such acci-
dents are illustrated.
1) First impact 2) Second impact
In an accident where the vehicle is struck from the
side more than once, the SRS side airbag deploysonly once.
Example: In the case of a double side impact colli- sion, first with one vehicle and immediately followed
by another from the same direction, once the SRSside airbag is activated on the first impact, it will notbe activated on the second.
SRS airbag system monitors
A diagnostic system continually monitors the readi- ness of the SRS airbag system while the vehicle is
being driven. The SRS airbag system warning light
“AIRBAG” will show normal system operation by
lighting for about 6 seconds when the ignition key is
turned to the “ON” position.
The following components are monitored by the indi-cator: Front sub sensor (Right hand side)
Front sub sensor (Left hand side)
Airbag control module (including impact sensors)
Frontal airbag module (Driver ’s side)

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Frontal airbag module (Passenger ’s side)
Side airbag sensor (Driver ’s side — if equipped)
Side airbag sensor (Passenger ’s side — if
equipped) Side airbag module (Driver ’s side — if equipped)
Side airbag module (Passenger ’s side — if
equipped) Seatbelt pretensioner (Driver ’s side)
Seatbelt pretensioner (Passenger ’s side)
All related wiring
In the event of a malfunction indicated by any of fol-
lowing, the vehicle should be taken promptly to your
nearest SUBARU dealer to have the system
checked. Unless checked and repaired, the SRS
airbags will not function reliably: Flashing or flickering of the indicator light.
No illumination of the warning light when the igni-
tion switch is first turned to the “ON” position.
Continuous illumination of the warning light.
Illumination of the warning light while driving.
SRS airbag system servicing
WARNING
When discarding an airbag module or scrap-
ping the entire car damaged by a collision,
consult your SUBARU dealer. 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 withor 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 har-
nesses of the SRS airbag system are coveredwith yellow insulation and system connectorsare yellow for easy identification.