Honda Prelude 1993 Service Manual page 1366

Description
The SRS is a safety device which, when used in conjunction with the seat belt. is designed to help protect the driver {and
front passenger) in a frontal impact exceeding a certain set limit.
The system is composed of left and right dash sensors, the SRS unit (includes cowl sensors), the cable reel, driver's air-
bag and front passenger's airbag (Si 4WS, Si VTEC: USA, SR 4WS,SR-V: Canada models).
SRS UNIT
OPERATION:
As shown in the diagram below, the left and right dash sensors are connected in parallel. The parallel set of sensots is
connected in series to each airbag inflator circuit and the car battery. In addition, a back-up power circuit is connected in
parallel with the car battery. The back-up power circuit and the cowl sensors are located inside the SRS unit.
For the SRS to operate:
{1) One or both cowl sensors and one or both dash sensors must activate.
(2) Electrical energy must be supplied to the airbag inftator by the battery, or by the back-up power circuit iJ the bat-
tery voltage is too low.
{3) The inflator charge must ignite and deploy the airbag.
It takes about O.l second from the beginning ot the airbag deployment until it is completely deflated (frontal collision
against a fixed wall at a speed of 30 mph t50 km/hl).
Selt-diagnosis systom
A seli-diagnosis circuit is built into the SRS unit; when the ignition switch is turned ON. the SRS indicator light comes on
and goes off after about six seconds if the system is operating normally. It the light does not come on, or does not go oft
atter six seconds. or if it comes on while driving, it indicates an abnormality in the system. The system must be inspected
and repaired as soon as possible.
AIRBAG
CABI-E REEL
I l - r
I A | R B A G l l
t t
t L . - l
FRONT
PASSENGER'S
AIRBAG
23-289