RT -2
RESTRAINTS
GENERAL
GENERAL
EFAC12FD
The supplemental restraint system (SRS) is designed to
supplement the seat belt to help reduce the risk or sever-
ity of injury to the driver and passenger by activating and
deploying the driver, passenger, side airbag and belt pre-
tensioner in certain frontal or side collisions.
The SRS (Airbag) consists of : a driver side airbag module
located in the center of the steering wheel, which contains
the folded cushion and an inflator unit ; a passenger side
airbag module located in the passenger side crash pad
contains the folded cushion assembled with inflator unit ;
side airbag modules located in the front seat contain the
folded cushion and an inflator unit ; curtain airbag mod-
ules located inside of the headliner which contains folded
cushions and inflator units. The impact sensing function
of the SRSCM is carried out by electronic accelerometer
that continuously measure the vehicle’s acceleration and
delivers a corresponding signal through amplifying and fil-
tering circuitry to the microprocessor.
SRSCM (SRS CONTROL MODULE)
SRSCM will detect front impact with front impact sensor,
and side impact with side impact sensor, and determine
airbag module deployment.
1.
DC/DC converter: DC/DC converter in power supply
unit includes up/down transformer converter, and pro-
vide ignition voltage for 2 front airbag ignition circuits
and the internal operation voltage of the SRSCM. If
the internal operation voltage is below critical value
setting, it will perform resetting.
2.
Safety sensor: Safety sensor is located in airbag ig-
nition circuit. Safety sensor will operate airbag circuit
at any deployment condition and release airbag cir-
cuit safely at normal driving condition. Safety sensor
is a double contact electro-mechanical switch that will
close detecting deceleration above certain criteria.
3.
Back up power supply: SRSCM has separate back
up power supply, that will supply deployment energy
instantly in low voltage condition or upon power failure
by front crash.
4.
Self diagnosis: SRSCM will constantly monitor cur-
rent SRS operation status and detect system failure
while vehicle power supply is on, system failure may
be checked with trouble codes using scan tool. (Hi-
Scan)
5.
Airbag warning lamp on: Upon detecting error, the
module will transmit signal to SRSCM indicator lamp
located at cluster. MIL lamp will indicate driver SRS
error. Upon ignition key on, SRS lamp will turn on for
about six seconds.
6.
Trouble code registration: Upon error occurrence in
system, SRSCM will store DTC corresponding to the
error. DTC can be cleared only by Hi-Scan. How-
ever, if an internal fault code is logged or if a crash is
recorded the fault clearing should not happen.
7.
Self diagnostic connector: Data stored in SRSCM
memory will be output to Hi-Scan or other external
output devices through connector located below
driver side crash pad.
8.
Once airbag is deployed, SRSCM should not be used
again but replaced.
9.
SRSCM will determine whether passenger put on
seat belt by the signal from built-in switch in seat belt
buckle, and deploy front seat airbag at each set crash
speed.
10. Side airbag deployment will be determined by
SRSCM that will detect satellite sensor impact signal
upon side crash, irrespective to seat belt condition.