Lexus ES300 (1997 year). Manual — part 560

SR–48

–

STEERING

POWER STEERING GEAR

1344

1997 LEXUS ES300 (RM511U)

13.

TORQUE STEERING WHEEL SET NUT
Torque: 35 N·m (360 kgf·cm, 26 ft·lbf)

14.

INSTALL STEERING WHEEL PAD
(See page

SR–16

)

15.

CHECK FRONT WHEEL ALIGNMENT
(See page

SA–4

)

RS01Y–41

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

RS–1

1345

1997 LEXUS ES300 (RM511U)

SRS AIRBAG

PRECAUTION

NOTICE:

The LEXUS ES300 is equipped with SRS, which comprises a driver airbag and a front passenger
airbag. Failure to carry out service operations in the correct sequence could cause the SRS to
unexpectedly deploy during servicing, possibly leading to a serious accident. Further, if a mis-
take is made in servicing the SRS, it is possible that the SRS may fail to operate when required.
Before performing servicing (including removal or installation of parts, inspection or replace-
ment), be sure to read the following items carefully, then follow the correct procedures de-
scribed in the repair manual.

Malfunction symptoms of the SRS are difficult to confirm, so the DTCs become the most impor-
tant source of information when troubleshooting. When troubleshooting the SRS, always in-
spect the DTCs before disconnecting the battery.

Even in cases of a minor collision where the SRS does not deploy, the steering wheel pad, front
passenger airbag assembly and airbag sensor assembly should be inspected (See page

RS–9

,

RS–23

and

RS–36

).

Never use SRS parts from another vehicle. When replacing parts, replace them with new parts.

Never disassemble and repair the steering wheel pad, front passenger airbag assembly or air-
bag sensor assembly in order to reuse it.

If the steering wheel pad, front passenger airbag assembly or airbag sensor assembly have
been dropped, or if there are cracks, dents or other defects in the case, bracket or connector,
replace them with new ones.

Use a volt/ohmmeter with high impedance ( 10 k

Ω

/V minimum) for troubleshooting the system’s

electrical circuits.

Information labels are attached to the periphery of the SRS components. Follow the instruc-
tions on the notices.

After work on the SRS is completed, perform the SRS warning light check (See page

DI–324

).

If the vehicle is equipped with a mobile communication system, refer to the precaution in the
IN section.

CAUTION:

Work must be started after 90 seconds from when the ignition switch is turned to the ”LOCK”
position and the negative (–) terminal cable is disconnected from the battery.
(The SRS is equipped with a back–up power source so that if work is started within 90 seconds
from disconnecting the negative (–) terminal cable of the battery, the SRS may be deployed.)

When the negative (–) terminal cable is disconnected from the battery, the memory of the clock
and audio system will be canceled. So before starting work, make a record of the contents mem-
orized in the audio memory system. When work is finished, reset the audio systems as they
were before and adjust the clock. To avoid erasing the memory in each memory system, never
use a back– up power supply from outside the vehicle.

Before repairs, remove the airbag sensor if shocks are likely to be applied to the sensor during
repairs.

Do not expose the steering wheel pad, front passenger airbag assembly or airbag sensor as-
sembly directly to hot air or flames.

RS0NZ–01

W03613

R09725

Spiral Cable

W03614

W04364

H01348

RS–2

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

1346

1997 LEXUS ES300 (RM511U)

OPERATION

1.

STEERING WHEEL PAD (with AIRBAG)

The inflater and bag of the SRS are stored in the steering wheel
pad and cannot be disassembled. The inflater contains a squib,
igniter charge, gas generant, etc., and inflates the bag when
instructed by the airbag sensor assembly.

2.

SPIRAL CABLE (in COMBINATION SWITCH)

A spiral cable is used as an electrical joint from the vehicle body
side to the steering wheel.

3.

FRONT PASSENGER AIRBAG ASSEMBLY

The inflater and bag of the SRS are stored in the front passen-
ger airbag assembly and cannot be disassembled. The inflater
contains a squib, igniter charge and gas generant, etc., and in-
flates the bag when instructed by the airbag sensor assembly.

4.

SRS WARNING LIGHT

The SRS warning light is located on the combination meter. It
goes on to alert the driver of trouble in the system when a mal-
function is detected in the airbag sensor assembly. In normal
operation condition when the ignition switch is turned to the
ACC or ON position, the light goes on for about 6 seconds and
then goes off.

5.

AIRBAG SENSOR ASSEMBLY

The airbag sensor assembly is mounted on the floor inside the
console box. The airbag sensor assembly consists of an airbag
sensor, safing sensor, diagnosis circuit and ignition control,
drive circuit, etc. It receives signals from the airbag sensor and
judges whether the SRS must be activated or not.

R11937

Airbag Sensor
Assembly

Front Passenger
Airbag Assembly

Steering Wheel
Pad

Instrument Panel
Junction Block

Junction
Block No. 1

Spiral
Cable

–

SUPPLEMENTAL RESTRAINT SYSTEM

SRS AIRBAG

RS–3

1347

1997 LEXUS ES300 (RM511U)

6.

SRS CONNECTORS

No.

Item

Application

(1)

Terminal Twin–Lock Mechanism

Connectors 1, 2, 3, 4, 5, 6, 7

(2)

Airbag Activation Prevention Mechanism

Connectors 1, 2, 3, 4

(3)

Electrical Connection Check Mechanism

Connectors 1

(4)

Connector Twin–Lock Mechanism

Connectors 2, 3, 4

(a)

All connectors in the SRS are colored in yellow to distin-
guish them from other connectors. Connectors having
special functions and specifically designed for the SRS
are used in the locations shown above to ensure high reli-
ability. These connectors use durable gold–plated termi-
nals.