2002 SUBARU IMPREZA WRX sensor

Seat, seatbelt and SRS airbags
1-24
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.
HB0373
When a seatbelt pretensioner is activated, an oper-
ating noise will be heard and a small amount of smoke will be released. These occurrences are nor-
mal 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. NOTE
Seatbelt pretensioners are not designed to
activate in minor frontal impacts, in side or rear
impacts or in roll-over accidents. The driver ’s seat and passenger ’s seat preten-
sioners and frontal SRS airbag operate simulta-
neously. 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
passenger’ s seatbelt retractor assemblies must
be replaced only by an authorized SUBARU
dealer. When replacing seatbelt retractor assem-
blies, use only genuine SUBARU parts. If either front seatbelt does not retract or can-
not be pulled out due to a malfunction or activa-
tion of the pretensioner, contact your SUBARUdealer as soon as possible. If the front seatbelt retractor assembly or sur-
rounding area has been damaged, contact your

Seat, seatbelt and SRS airbags
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SUBARU dealer as soon as possible. When you sell your vehicle, we urge you to
explain to the buyer that it has seatbelt preten-sioners by alerting him to the contents of thissection.
WARNING
To obtain maximum protection, the occu-
pants should sit in an upright position with their seatbelts properly fastened. Refer to the
“Seatbelts” section in this chapter.
Do not modify, remove or strike the front
seatbelt retractor assemblies or surrounding
area. This could result in accidental activationof the seatbelt pretensioners or could makethe system inoperative, possibly resulting in
serious injury. Seatbelt pretensioners have no
user-serviceable parts. For required servicingof front seatbelt retractors equipped with seat-
belt pretensioners, see your nearest SUBARU
dealer. When discarding front seatbelt retractor
assemblies or scrapping the entire car due to
collision damage or for other reasons, consult
your SUBARU dealer.
System monitors
HG1016BA
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)

Seat, seatbelt and SRS airbags
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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-
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 systemare yellow for easy identification. Do not use
electrical test equipment on any circuit related to 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-

Seat, seatbelt and SRS airbags
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HG1034BB
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)
9) Side airbag sensor (passenger’ s side)
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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Operation
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 de-
flating SRS airbag after deployment is shorter thanthe 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 airbagwould 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.

Seat, seatbelt and SRS airbags
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deploys between the occupant and the door panel
and supplements the seatbelt by reducing the im-pact on the occupant’s chest.
Operation
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 deflating of the SRS side airbag after de-
ployment is shorter than the blink of an eye.

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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.
HG1016BA
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)
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.

Seat, seatbelt and SRS airbags
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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.
CAUTION
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. Under the center console
Inside each front fender
Steering wheel and column and nearby
areas Top of the dashboard on front passenger ’s
side and nearby areas Each front seat and nearby area (only for ve-
hicle with SRS side airbags) Inside each center pillar
In the event that the SRS airbag is deployed, re-
placement of the system should be performed
only by an authorized SUBARU dealer. When the
components of the SRS airbag system are re-
placed, use only genuine SUBARU parts.
To ensure their long-term reliability, the SRS airbags must be inspected by a SUBARU dealer ten years
after the date of manufacture, which is shown on the
certification plate attached to the driver ’s door jamb.