Lexus SC300 / Lexus SC400. Manual - part 779

(1) Terminal Twin–Lock Mechanism

Each connector has a two–piece construction consisting of
a housing and a spacer. This design secures the locking of
the terminal by two locking devices (the spacer and the lance)
to prevent terminals from coming out.

(2) Airbag Activation Prevention Mechanism

Each connector contains a short spring plate. When the con-
nector is disconnected, the short spring plate automatically
connects the power source and grounding terminals of the
squib.

HINT: The illustration shows connectors 



, 



 and 



.

 Con-

nector 

 has short spring plates on the female terminal side.

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SUPPLEMENTAL RESTRAINT SYSTEM

OPERATION

RS–11

(3) Electrical Connection Check Mechanism

This mechanism is designed to electrically check if connec-
tors are connected correctly and completely. The electrical
connection check mechanism is designed so that the con-
nection detection pin connects with the diagnosis terminals
when the connector housing lock is in the locked condition.

HINT: The illustration shows connectors 



 and 



 Connector,

also has the same operating principle.

RS–12

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SUPPLEMENTAL RESTRAINT SYSTEM

OPERATION

 (4) Connector Twin–Lock Mechanism

With this mechanism connectors (male and female connec-
tors) are locked by 2 locking devices to increase connection
reliability. If the primary lock is incomplete, ribs interfere and
prevent the secondary lock.

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SUPPLEMENTAL RESTRAINT SYSTEM

OPERATION

RS–13

When the vehicle is involved in a frontal collision in the
hatched area (Fig. 1) and the shock is larger than a predeter-
mined level, the SRS is activated automatically. A safing sen-
sor is designed to go on at a smaller deceleration rate than
the front and center airbag sensors. As illustrated in Fig. 2,
ignition is caused when current flows to the squib, which hap-
pens when a safing sensor and a front airbag sensor and/or
the center airbag sensor go on simultaneously. When a de-
celeration force acts on the sensors, two squibs in the driver
airbag and front passenger airbag ignite and generate gas.
The gas discharging into the driver and front passenger air-
bags rapidly increases the pressure inside the bags breaking
open the steering wheel pad and instrument panel door.
Bag inflation then ends, and the bags deflate as the gas is
discharged through discharge holes at the bag’s rear or side.

RS–14

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SUPPLEMENTAL RESTRAINT SYSTEM

OPERATION