Page 210 of 364

TECHNICAL FEATURES
GENERAL00-25
SUPPLEMENTAL RESTRAINT SYSTEM
(SRS*)
NOTE: *SRS: Supplemental Restraint System
The SRS is designed to supplement the front seat
belts. It eliminates or reduces injury to the front pas
-
senger(s) by deploying air bag(s) in case of a
head-on collision.
DRIVER’S SEAT/PASSENGER’S SEAT SRS AIR BAG
AC208256AB
Driver's seat
Passenger's seat
Driver's and
pa sse nger's SRS a ir bag s have be en
inst alled to all the vehicle s as st andard to sof ten
blows to the front pa sseng ers' head and che st areas d
uring a fro nta l coll ision , i n cre asin g sa fety a gainst an
acciden t with a frontal collision.
SEAT BEL T WITH PRE-TENSIONER
AC208129
AC207230AC207336
ACPipe Gear
Ball Spool
Gas generator
The seatbelt incorpo
rating the pre -tensioner auto-
matically winds the seatbelt upo n front impact to
reduce forward shif ting of the passenge r.
Upo n front impact the pre-ten sion er ig nites the g as
generat or and emits gas with the SRS-ECU signal
whe n t he front imp act sen sor , att ached to the front of the bo
dy, det ects a n imp act t hat excee ds t he pe rmis
-
sible limit. By th is gas p ressure, a ball moves in th e
p ipe and rot ates the ge ar. This gear rotation operate s
the spool in the direction of ret racting the belt, and
the webbing is retr acted.
Page 305 of 364

SYSTEM CONSTRUCTION
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)52B-13
SEAT BELT WITH PRE-TENSIONER
M2521008000195
AC208129
AC207230AC207336ACPipe Gear
Ball Spool
Gas generator
The seatbelt incorpo
r ating the pre - tensioner auto-
matically winds the seatbelt upo n front imp a ct to
reduce forward shif
ting of th e p a ssenge r .
Upon front imp a ct the pre-ten s ion e r ig nites the g a s
generat
or and emit s gas with the SRS-ECU signal
whe
n t he front imp a ct sen s or , att a ched to the front of
the bo
dy , dete c t s a n imp a ct t hat excee d s t he per mis
-
sible limit. By this g a s p r essure, a ball moves in the
p
i p e and rot a tes the g ear . This gear rot a tion operat es
the spool
in the directio n of ret r acting the belt, and
the webbing is retra
c ted .
SRS-ECU
M25210070 0048 2
The SRS-ECU incorp orates an an alog ue G-sensor
and safing
G-sensor for fro n t a l collisions.
In frontal collision s , the dr iver's an d front p a ssenge r's
air ba
gs d eploy only when both t he ana logue and
safing G-sensors detect
simult a neously a co lli
-
sion -indu ced G of a le vel exceed ing the thresh old as
in the
case with the conve n tion al system.
The SRS-ECU is prov ide d with t he followin g cap a b i l-
ities:
•Backup p o wer su pply in case of po we r failure in
c
o lli si ons: Ba cku p ca p a cito r
•Boosting function in ca se of battery volt a ge drop :
DC-DC converter
•Self-diag nosis fu nction to a v oid syste m 's opera-
tion errors and imp r ove it s reliabilit y
CAUTION
Never disassemble the SRS-ECU.
DIAGNOSIS FUNCTION
The SRS-ECU has the following functions to make
system check using M.U.T.-III easy.
•Diagnosis code set
•Service data output
Page 313 of 364

ComponentNo.Function
SensorWheel speed sensor1Sends alternating current signals at frequencies which are
proportional to the rotation speeds of each wheel to the
active stability control system-ECU
Magnetic encoder for wheel
speed detection2The wheel speed sensor is a pulse generator. When the
magnetic encoder for wheel speed detection (a plate on
which north and south pole sides of the magnets are
arranged alternately) rotates, it outputs frequency pulse
signal in proportion to each wheel speed.
Stop lamp switch3Sends a signal to the active stability control system-ECU
to indicate whether the brake pedal is depressed or not.
Parking brake switch4Outputs the signal indicating whether the parking brake
lever is pulled or not to ASC-ECU.
Brake fluid level switch5Outputs the signal indicating whether the brake fluid is
filled to the lowest limit level or not to ASC-ECU.
G and yaw rate sensor6Detects the lateral acceleration and the yaw rate for the
vehicle. Then it sends a signal through the CAN bus line to
the active stability control system-ECU.
Steering wheel sensor7Detects the steering wheel angle, and sends a signal to
the active stability control system-ECU through the CAN
bus line.
ASC OFF switch8Outputs the ASC ON/OFF signal to ASC-ECU.
Pressure sensor9Is incorporated in the hydraulic unit, and informs the active
stability control system-ECU of the brake fluid pressure in
the master cylinder.
ActuatorHydraulic unit10Drives the solenoid valves and pump motor according to
signals from the ABS/active stability control system-ECU in
order to control the brake hydraulic pressure for each wheel.
ABS warning lamp11Illuminates in response to signals from the active stability
control system-ECU when a problem develops in the
system.
Brake warning lamp12Illuminates in response to signals from the active stability
control system-ECU when a problem develops in the EBD
system or the brake fluid level is low.
Active stability control system
(ASC) indicator lamp 13Receives a signal from the active stability control
system-ECU, and flashes to inform the driver that the
system is operating, or illuminates to inform the driver of
system shutdown.
ASC OFF indicator lamp14Informs the driver of the ASC shutdown by illuminating
with the signal from ASC-ECU.
Diagnosis connector15Sets the diagnosis codes and allows communication with
the M.U.T.-III.
Engine-ECU16Receives a signal from the active stability control
system-ECU to control the engine output.
Anti-skid Brake/Active Stability Control
System control unit (ABS/active stability
control system-ECU)17Controls actuators (described above) based on the signals
coming from each sensor.
Controls the self-diagnostics and fail-safe functions.
Controls the diagnostic function (M.U.T.-III compatible).
GENERAL
ACTIVE STABILITY CONTROL SYSTEM (ASC)35C-3