2006 SUBARU IMPREZA WRX sensor

1-20 Seat, seatbelt and SRS airbags
Front seatbelt pretensioners
The driver ’s and front passenger ’s seat-
belts 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 colli-
sion.
The pretensioner sensor also serves as
the frontal SRS airbag sensor. If the sen-
sor detects a certain predetermined
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 restrains the front
seat occupant.
When a seatbelt pretensioner is activated, an operating 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 there-
fore must be replaced.
NOTE
Seatbelt pretensioners are not de-
signed to activate in minor frontal im-
pacts, in side or rear impacts or in roll-
over accidents.
The driver ’s seat and passenger ’s
seat pretensioners and frontal SRS air-
bag operate simultaneously.
Pretensioners are designed to func-
tion on a one-time-only basis. In the
event that a pretensioner is activated,
both the driver ’s and front passenger ’s
seatbelt retractor assemblies must be
replaced only by an authorized
SUBARU dealer. When replacing seat-
belt retractor assemblies, use only
genuine SUBARU parts.
If either front seatbelt does not re-
tract or cannot be pulled out due to a
malfunction or activation of the preten-
sioner, contact your SUBARU dealer as soon as possible.
If the front seatbelt retractor assem-
bly or surrounding area has been dam-
aged, contact your SUBARU dealer as
soon as possible.
When you sell your vehicle, we urge
you to explain to the buyer that it has
seatbelt pretensioners by alerting him
to the contents of this section.
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To obtain maximum protection,
the occupants should sit in an up-
right position with their seatbelts
properly fastened. Refer to the “ Seatbelts ” section in this chap-
ter.
Do not modify, remove or strike
the front seatbelt retractor assem-
blies or surrounding area. This
could result in accidental activa-
tion of the seatbelt pretensioners
or could make the system inoper-
ative, possibly resulting in seri-
ous injury. Seatbelt pretensioners
have no user-serviceable parts.
For required servicing of front
seatbelt retractors equipped with
seatbelt pretensioners, see your
nearest SUBARU dealer.

Seat, seatbelt and SRS airbags 1-21
– CONTINUED –
System monitors
A diagnostic system continually monitors
the readiness of the seatbelt pretensioner
while the vehicle is being driven. The seat-
belt pretensioners share the control mod-
ule with the SRS airbag system. There-
fore, if any malfunction occurs in a seat-
belt pretensioner, the SRS airbag system
warning light will illuminate. The SRS air-
bag system warning light will show normal
system operation by lighting for approxi-
mately 6 seconds when the ignition switch is turned to the
“ON ” position.
The following components are monitored
by the indicator:
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 (Front passen-
ger ’s side)
Side airbag sensor (Center pillar right
hand side)
Side airbag sensor (Center pillar left
hand side)
Side airbag module (Driver ’s side)
Side airbag module (Front passenger ’s
side)
Seatbelt pretensioner (Driver ’s side)
Seatbelt pretensioner (Front passen-
ger ’s side)
Seatbelt buckle switch (Driver ’s side)
Seatbelt buckle switch (Front passen-
ger ’s side)
Driver ’s seat position sensor
Front passenger ’s seatbelt tension sen-
sor
Front passenger ’s occupant detection
system weight sensor
Front passenger ’s occupant detection
control module
Front passenger ’s frontal airbag ON
and OFF indicator
All related wiringWhen discarding front seatbelt re-
tractor assemblies or scrapping
the entire vehicle due to collision
damage or for other reasons, con-
sult your SUBARU dealer.
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If the warning light exhibits any of
the following conditions, there may
be a malfunction in the seatbelt pre-
tensioners and/or SRS airbag sys-
tem. Immediately take your vehicle
to your nearest SUBARU dealer to
have the system checked. Unless
checked and properly repaired, the
seatbelt pretensioners and/or SRS
airbag will not operate properly in
the event of a collision, which may
increase the risk of injury.
Flashing or flickering of the indi-
cator light
No illumination of the warning
light when the ignition switch is
first turned to the “ON ” position
Continuous illumination of the
warning light
Illumination of the warning light
while driving

1-22 Seat, seatbelt and SRS airbags
System servicing
NOTE
If the front part of the vehicle is dam-
aged in an accident to the extent that
the seatbelt pretensioner does not op-
erate, contact your SUBARU dealer as
soon as possible.
Precautions against vehicle
modification
Always consult your SUBARU dealer if
you want to install any accessory parts to
your vehicle.
When discarding a seatbelt retrac-
tor assembly or scrapping the en-
tire vehicle damaged by a colli-
sion, consult your SUBARU deal-
er.
Tampering with or disconnecting
the system ’s wiring could result in
accidental activation of the seat-
belt pretensioner and/or SRS air-
bag or could make the system in-
operative, which may result in se-
rious injury. The wiring harnesses
of the seatbelt pretensioner and
SRS airbag systems are covered
with yellow insulation 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 SRS airbag sys-
tems. For required servicing of
the seatbelt pretensioner, see
your nearest SUBARU dealer.
The front sub sensors are located in
both front fenders and the SRS air-
bag control module including the
impact sensors is located under the
center console. If you need service
or repair in those areas or near the
front seatbelt retractors, we recom-
mend that you have an authorized
SUBARU dealer perform the work.
Do not perform any of the following
modifications. Such modifications
can interfere with proper operation
of the seatbelt pretensioners.
Attachment of any equipment
(bush bar, winches, snow plow,
skid plate, etc.) other than genu-
ine SUBARU accessory parts to
the front end.
Modification of the suspension
system or front end structure.
Installation of a tire of different
size and construction from the
tires specified on the vehicle plac-
ard attached to the driver ’s door
pillar or specified for individual
vehicle models in this Owner ’s
Manual.

1-38 Seat, seatbelt and SRS airbags
Components
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2019
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100701 1) Airbag control module (including impact
sensors)
2) Frontal airbag module (driver ’s side)
3) Frontal airbag module (front passen-
ger’s side)
4) Front sub sensor (left-hand side)
5) Front sub sensor (right-hand side)
6) Side airbag module (driver ’s side)
7) Side airbag module (front passenger ’s
side)
8) Side airbag sensor (center pillar left-
hand side)
9) Side airbag sensor (center pillar right- hand side)
10)Airbag wiring (yellow)
11)Seatbelt pretensioner (driver ’s side)
12) Seatbelt pretensioner (front passenger ’s
side)
13)Seatbelt buckle switch (front passen- ger’s side)
14)Seatbelt buckle switch (driver ’s side)
15) Driver ’s seat position sensor
16)Front passenger ’s seatbelt tension sen-
sor
17)Front passenger ’s occupant detection
system weight sensor
18)Front passenger ’s occupant detection
control module
19)Front passenger ’s frontal airbag ON and
OFF indicator
20)SRS airbag system warning light

Seat, seatbelt and SRS airbags 1-41
– CONTINUED –
Driver’s SRS frontal airbag
The driver ’s SRS frontal airbag uses a
dual stage inflator. The inflator operates in
different ways depending on the severity
of impact, backward-forward adjustment
of the driver ’s seat position and whether or
not he/she is wearing the seatbelt.
The backward-forward adjustment of the
driver ’s seat position is monitored by the
driver ’s seat position sensor under the driver
’s seat.
Whether or not the driver is wearing the
seatbelt is monitored by the seatbelt buck-
le switch.
Observe the following precautions. Failure
to do so may cause the seatbelt buckle
switch and/or the seat position sensor to
malfunction, preventing the Subaru ad-
vanced frontal airbag system from func-
tioning correctly or causing the system to
fail.
Do not place articles/metal objects or in-
stall any accessory other than a genuine
SUBARU accessory under the driver ’s
seat. Do not allow the rear seat occupant
to kick the driver ’s seat or push up its bot-
tom surface with his/her feet.
Do not place a magnet near the seatbelt
buckle or under the driver ’s seat.
If the seatbelt buckle switch and/or the
driver ’s seat position sensor have failed,
the SRS airbag system warning light will il-
luminate. Although the driver ’s SRS fron-
tal airbag can deploy regardless of the
backward-forward adjustment of the driv-
er ’s seat position even when the warning
light is on, have the system inspected by
your SUBARU dealer immediately if the
SRS airbag system warning light comes
on.
NOTE
The driver ’s SRS side airbag and seat-
belt pretensioner are not controlled by
the Subaru advanced frontal airbag
system.
Front passenger ’s SRS frontal air-
bag
The front passenger ’s SRS frontal airbag
uses a dual stage inflator. The inflator op-
erates in different ways depending on the
severity of impact.
The total load on the seat is monitored by
the occupant detection system ’s weight
sensor located under the seat.
The system has another sensor that mon-
itors the tension of the front passenger
seatbelt. Using the total seat load and
seatbelt tension data from the sensors,
the occupant detection system deter-
mines whether the front passenger ’s SRS
frontal airbag should or should not be in-
flated.
The occupant detection system may not
inflate the front passenger ’s SRS frontal
airbag even when the driver ’s SRS frontal
airbag deploys. This is normal.
Observe the following precautions. Failure
to do so may prevent the Subaru ad-
vanced frontal airbag system from func-
tioning correctly or cause the system to
fail.
Do not attach accessories to the
windshield, or fit an extra-wide mir-
ror over the rear view mirror. If the
SRS airbag deploys, those objects
could become projectiles that could
seriously injure vehicle occupants.
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Seat, seatbelt and SRS airbags 1-47
– CONTINUED –
Operation
A) Driver’s side
B) Passenger ’s side
1) SRS AIRBAGs deploy as soon as a collision occurs.
2) After deployment, SRS AIRBAGs start to deflate im mediately so that the driver’s vision is not
obstructed.
A B
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2
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The SRS airbag can function only when
the ignition switch is in the “ON ” position.
The Subaru advanced frontal airbag sys-
tem is designed to determine the activa-
tion or deactivation condition of the front
passenger ’s SRS frontal airbag depend-
ing on the total load on the front passen-
ger ’s seat monitored by the front passen-
ger ’s occupant detection system weight
sensor. For this reason, only the driver ’s
SRS frontal airbag may deploy in the
event of a collision, but this does not mean
failure of the system.
If the front sub sensors inside both front
fenders and the impact sensors in the air-
bag control module detect a predeter-
mined amount of force during a frontal col-
lision, the control module sends signals to
the airbag module(s) (only driver ’s module
or both driver ’s and front passenger ’s
modules) instructing the module(s) to in-
flate the SRS frontal airbag(s). The driv-
er ’s and front passenger ’s SRS frontal air-
bags use dual stage inflators. The two in-
flators of each airbag are triggered either
sequentially or simultaneously, depending
on the severity of impact, backward-for-
ward adjustment of the driver ’s seat posi-
tion and fastening/unfastening of the seat-
belt in the case of the driver ’s SRS frontal
airbag and depending on the severity of
impact and the total load on the seat in the

Seat, seatbelt and SRS airbags 1-53
– CONTINUED –
Operation
1) SRS side airbag deploys as soon as a
collision occurs.
2) SRS side airbag protects the front pas- senger ’s head and chest.
3) After deployment, SRS side airbag starts to deflate immediately.
The SRS side airbag can function only
when the ignition switch is in the “ON ” po-
sition.
The driver ’s and front passenger ’s SRS
side airbags deploy independently of each
other since each has its own impact sen-
sor. Also, the SRS side airbag deploys in-
dependently 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 ei-
ther sensor detects a certain predeter-
mined amount of force during a side im-
pact collision, the control module sends a
signal to the side airbag module on the im-
pacted side of the vehicle, instructing it to
inflate the SRS side airbag. Then the side
airbag module produces gas, which in-
stantly inflates the SRS side airbag. After
deployment, the SRS side airbag will de-
flate in a few seconds.
The SRS side airbag deploys even when
no one occupies the seat on the side on
which an impact is applied.
When the SRS side airbag deploys, a sud-
den, fairly loud inflation noise will be heard
and some smoke will be released. These
occurrences are normal result of the de-
ployment. This smoke does not indicate a
fire in the vehicle.
Do not put any kind of cover or
clothes or other objects over either
front seatback and do not attach la-
bels or stickers to the front seat sur-
face on or near the SRS side airbag.
They could prevent proper deploy-
ment of the SRS side airbag, reduc-
ing protection available to the front
seat ’s occupant.
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1-56 Seat, seatbelt and SRS airbags
Examples of the types of accidents
in which the SRS side airbag will ba-
sically not deploy.
1) The vehicle is involved in a frontal colli-
sion with another vehicle (moving or sta-
tionary).
2) The vehicle is struck from behind.
The SRS side airbag is basically not de-
signed to deploy if the vehicle is involved
in a frontal collision or is struck from be-
hind. Examples of such accidents are il-
lustrated.
1) First impact
2) Second impact
In an accident where the vehicle is struck
from the side more than once, the SRS
side airbag deploys only once on the first
impact.
Example: In the case of a double side im-
pact collision, first with one vehicle and
immediately followed by another from the
same direction, once the SRS side airbag
is activated on the first impact, it will not be
activated on the second.
SRS airbag system monitors
A diagnostic system continually monitors
the readiness of the SRS airbag system
(including front seatbelt pretensioners)
while the vehicle is being driven. The SRS
airbag system warning light “AIRBAG ” will
show normal system operation by lighting
for approximately 6 seconds when the ig-
nition switch is turned to the “ON ” position.
The following components are monitored
by the indicator:
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 (Front passen-
ger ’s side)
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