Lexus ES300 (1997 year). Manual — part 561

Z05953

Spacer

Housing

Female

Male

R10587

When Connector is Connected

When Connector is Disconnected

Short Spring Plate

Housing

Housing

Terminal

Connectors

Short Spring Plate

Squib

Closed Circuit

Squib

Short Spring Plate ON

Contacting Male Terminal

Short Spring Plate

RS–4

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

1348

1997 LEXUS ES300 (RM511U)

(1)

Terminal Twin–Lock Mechanism
Each connector has a two–piece component con-
sisting of a housing and a spacer. This design en-
ables the terminal to be locked securely by two lock-
ing devices (the retainer and the lance) to prevent
terminals from coming out.

(2)

Airbag Activation Prevention Mechanism
Each connector contains a short spring plate. When
the connector is disconnected, the short spring
plate automatically connects positive (+) terminal
and negative (–) terminal of the squib.

HINT:
The type of connector shown above is used for connectors ”2”,
”3” and ”4” in the diagram on the preceding page.

W02758

Disconnection Detection Pin

Half Connection

Complete Connection

Terminal for Diagnosis

Terminal for
Diagnosis

AB0089

Secondary Lock

Primary Lock

Lock

Lock

Primary Lock Incomplete

(Secondary Lock Prevented)

Primary Lock Complete

(Secondary Lock Permitted)

Twin–Lock Completed

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

RS–5

1349

1997 LEXUS ES300 (RM511U)

(3)

Electrical Connection Check Mechanism
This mechanism electrically checks that connectors
are connected correctly and completely. The electri-
cal connection check mechanism is designed so
that the disconnection detection pin connects with
the diagnosis terminals when the connector hous-
ing lock is locked.

(4)

Connector Twin–Lock Mechanism
With this mechanism connectors (male and female
connectors) are locked by 2 locking devices to in-
crease the connection reliability. If the primary lock
is incomplete, ribs interfere and prevent the sec-
ondary lock.

Z14034

Fig.1

Fig.2

Power Source

Safing

Sensor

Squibs

Deceleration
Sensor

RS–6

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

1350

1997 LEXUS ES300 (RM511U)

(b)

When the vehicle is involved in a frontal collision in the
hatched area (Fig. 1) and the shock is larger than the pre-
determined level, the SRS is activated automatically. A
safing sensor is designed to go on at a smaller decelera-
tion rate than the airbag sensor. As illustrated in Fig. 2,
ignition is caused when current flows to the squib, which
happens when a safing sensor and the airbag sensor go
on simultaneously. When a deceleration force acts on the
sensors, 2 squibs in the driver airbag and front passenger
airbag ignite and generate gas. The gas discharging into
the driver airbag and front passenger airbag rapidly in-
creases 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.

RS00Y–02

W03844

Column Upper Cover

Spiral Cable

Steering Wheel

7.1 (72, 63 in.·lbf)

35 (360, 26 in.·lbf)

Steering Wheel Pad

Steering Wheel
Lower No.2 Cover

Lower No.2
Cover

Column Lower Cover

Lower LH insert
Sub–Assembly

Cowl Side Trim

Front Door Scuff Plate

Lower No.1 insert Sub–Assembly

N·m (kgf·cm, ft·lbf)

: Specified torque

Torx Screw

–

SUPPLEMENTAL RESTRAINT SYSTEM

STEERING WHEEL PAD AND SPIRAL CABLE

RS–7

1351

1997 LEXUS ES300 (RM511U)

STEERING WHEEL PAD AND SPIRAL CABLE

COMPONENTS