2002 SUBARU LEGACY sensor

Seat, seatbelt and SRS airbags1-29
–
CONTINUED –
Front seatbelt pretensioners
WARNING
To obtain maximum protection, occupants should sit in an up-
right position with their seatbelts properly fastened. Refer to
“Seatbelts” section in this chapter.
Do not modify, remove or strike the front seatbelt retractor as-
semblies or surrounding area. This could result in accidental ac-tivation of the seatbelt pretensioners or could make the system
inoperative, possibly resulting in serious injury. Seatbelt preten-sioners have no user-serviceable parts. For required servicing of
front seatbelt retractors equipped with seatbelt pretensioners,
see your nearest SUBARU dealer. When discarding front seatbelt retractor assemblies or scrap-
ping the entire car due to collision damage or for other reasons,
consult your SUBARU dealer.
HB0373
Seatbelt retractor assembly (Pretensioner)
The driver
’s and front passenger ’s seatbelts have a seatbelt preten-
sioner. 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 a SRS frontal airbag sensor. If
the sensor detects a certain predetermined amount of force during a
frontal collision, the front seatbelt is quickly drawn back in by the re-
tractor to take up the slack so that the belt more effectively restrains

Seat, seatbelt and SRS airbags1-31
–
CONTINUED –
System monitors
HB4010EC
A diagnostic system continually monitors the readiness of the seatbelt
pretensioner while the vehicle is being driven. The seatbelt preten-
sioners share the control module with the airbag system. Therefore, if
any malfunction occurs in a seatbelt pretensioner, the SRS airbag sys-
tem warning light will illuminate. 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 indicator: 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 following, the vehicle
should be taken promptly to your nearest SUBARU dealer to have the
system checked. Unless checked and repaired, the seatbelt preten-
sioners and airbags will not function reliably: Flashing or flickering of the indicator 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.

1-32
System servicing
WARNING
When discarding a seatbelt retractor assembly or scrapping
the entire car damaged by a collision, consult your SUBARU deal-
er. Tampering with or disconnecting the system ’s wiring could re-
sult in accidental activation of the seatbelt pretensioner and/orairbag or could make the system inoperative, which may result in
serious injury. The wiring harnesses of the seatbelt pretensionerand SRS airbag systems are covered with yellow insulation andthe connectors of the system are yellow for easy identification.Do not use electrical test equipment on any circuit related to theseatbelt pretensioner and airbag systems. For required servicing
of the seatbelt pretensioner, see your nearest SUBARU dealer.
CAUTION
The front sub sensors are located in both front fenders and theairbag control module including the impact sensors is locatedunder the center console. If you need service or repair in those
areas or near the front seatbelt retractors, we recommend thatyou have an authorized SUBARU dealer perform the work.
NOTE If the front part of the vehicle is damaged in an accident to the extent that the seatbelt pretensioner does not operate, contactyour SUBARU dealer as soon as possible.

Seat, seatbelt and SRS airbags1-47
–
CONTINUED –
Components
HB1079DB
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
(passenger’ s side)
8 Side airbag module
(driver’ s side — if equipped)
9 Side airbag module
(passenger’ s side — if
equipped)
Q Side airbag sensor
(driver’ s side)
W Side airbag sensor
(passenger’ s side)
E Airbag wiring (yellow)

Seat, seatbelt and SRS airbags1-51
–
CONTINUED –
SRS airbags deploy as soon as a collision occurs. After deployment, SRS airbags start to deflate immediately
so that the driver’svision is not obstructed.
OM-H0384
Driver’s side Passenger’s side
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, whichinstantly inflates driver ’s and passenger ’s SRS frontal airbags. After
the deployment, the SRS airbags immediately start to deflate so thatthe 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 together with driv-
er’ s SRS frontal airbag even when no one occupies the front passen-
ger’ s seat.
When the SRS frontal airbags deploy, the driver ’s and front passen-
ger’ 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 vision and will not interfere with the driver ’s
ability to maintain control of the vehicle.

1-58
SRS side airbag deploys as soon as a collision occurs.
After deployment, SRS sideairbag starts to deflate immedi-
ately. HB0359
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 indepen-
dently of each other since each has its own impact sensor. Also, the
SRS side airbag deploys independently of the frontal airbags in thesteering wheel and instrument panel. An impact sensor is incorporated into each of the vehicle ’s center pil-
lars. 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, instruct-
ing it to inflate the SRS side airbag. Then the side airbag module pro-duces gas, which instantly inflates the SRS side airbag. After the de-
ployment, 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 occupies the seat on the side of which an impact is applied.

1-62
SRS airbag system monitors
HB4010EC
A diagnostic system continually monitors the readiness of the SRS air-
bag 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 about 6 seconds when the igni-
tion key 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 (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 following, 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:

Seat, seatbelt and SRS airbags1-63
–
CONTINUED –
Flashing or flickering of the indicator 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.
SRS airbag system servicing
WARNING
When discarding an airbag module or scrapping 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 near-
est SUBARU dealer. Tampering with or disconnecting the sys-
tem’ s wiring could result in accidental inflation of the SRS airbag
or could make the system inoperative, which may result in seri-
ous injury. The wiring harnesses of the SRS airbag system arecovered with yellow insulation and system connectors are yellowfor easy identification.
CAUTION
If you need service or repair in areas listed below, we recommend
that you have an authorized 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 vehicles with SRS
side airbags) Inside each center pillar