SRS Airba g Syste m - '9 9 - 0 1 Model s
SRS Airba g
The SR S is a safet y devic e which , whe n use d i n conjunctio n wit h th e sea t belt , i s designe d t o hel p protec t th e drive r an d
fron t passenge r i n a fronta l impac t exceedin g a certai n se t limit . Th e syste m consist s o f th e SR S uni t (including safing sen -
so r an d fron t impac t sensor) , th e cabl e reel , th e driver' s airba g an d fron t passenger' s airbag .
Sid e Airbag s
Sid e airbag s locate d i n eac h fron t seat-bac k ca n hel p protec t th e uppe r tors o o f th e drive r o r fron t sea t passenge r during a
moderat e t o sever e sid e impact . Sensor s i n eac h doo r sil l an d i n th e SR S uni t detec t suc h a n impac t an d instantl y inflat e
th e driver' s o r th e passenger' s sid e airbag . Onl y on e sid e airba g wil l deplo y durin g a sid e impact . I f th e impac t i s o n th e
passenger' s side , th e passenger' s sid e airba g wil l deplo y eve n if ther e is n o passenger .
Th e sid e airba g syste m als o include s a n Occupan t Positio n Detectio n Syste m (OPDS) . Thi s syste m consist s o f sensor s an d
a contro l uni t locate d i n th e fron t passenger' s seat-back . Th e contro l uni t send s occupan t heigh t an d positio n dat a t o th e
SR S unit . I f th e SR S uni t determine s tha t th e fron t passenger' s hea d i s i n th e deploymen t pat h o f th e sid e airbag , i t wil l
automaticall y disabl e th e airbag . Whe n th e sid e airba g i s disabled , th e Sid e Airba g indicato r ligh t i n th e gaug e assembl y
alert s th e drive r tha t th e passenger' s sid e airba g wil l no t deplo y i n a sid e impact .
Sea t Bel t Tensione r
Th e sea t bel t tensione r i s linke d wit h th e SR S airbag s t o furthe r increas e th e effectivenes s o f th e sea t belt . I n a front-en d
collision , th e tensione r instantl y retract s th e bel t firml y t o secur e th e occupant s i n thei r seats .
Operatio n
The mai n circui t i n th e SR S uni t sense s an d judge s th e forc e o f impac t and , i f necessary , ignite s th e inflato r charges . I f bat -
ter y voltag e i s to o lo w o r powe r i s disconnecte d du e t o th e impact , th e voltag e regulato r an d th e back-u p powe r circui t
respectivel y wil l kee p voltag e a t a constan t level .
Fo r th e SR S to operate :
Airba g an d Sea t Bel t Tensione r
(1 ) Th e fronta l impac t senso r mus t activate , an d sen d electri c signal s t o th e microprocessor .
(2 ) Th e microprocesso r mus t comput e th e signals , an d dependin g o n th e severit y o f th e collisio n an d whethe r th e sea t
bel t buckl e switc h i s O N o r OFF , i t send s th e appropriat e signal s t o th e airba g inflator s an d sea t bel t tensioners .
(3 ) Th e inflator s tha t receive d signal s mus t ignit e an d deplo y th e units .
Sid e Airba g
(1 ) Th e sid e impac t sensor s mus t activate , an d sen d electri c signal s t o th e microprocessor .
(2 ) Th e microprocesso r mus t comput e th e signal s an d sen d the m to th e sid e airba g inflators . Howeve r th e microproces -
so r cut s of f th e signal s t o th e fron t passenger' s sid e airba g i f th e SR S uni t determine s tha t th e fron t passenger' s hea d
i s i n th e deploymen t pat h o f th e sid e airbag .
(3 ) Th e inflato r tha t receive d th e signa l mus t ignit e an d deplo y th e sid e airbag .
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