Lexus RX300 (MCU15). Service manual — part 3

REMOVAL

INSTALLATION

SYMBOL

MEANING

ILLUSTRATION

SYMBOL

MEANING

ILLUSTRATION

Remove
Weld
Points

(Outside)

(Middle)

(Inside)

HINT:

Panel position symbols are as seen from

the working posture.

Spot Weld

Mig Plug
Weld

Spot MIG
Weld

Weld points

Remove weld point and panel position

Weld points

Weld method and panel position

— 2

— 2

REMOVAL

INSTALLATION

SYMBOL

MEANING

ILLUSTRATION

SYMBOL

MEANING

ILLUSTRATION

Remove
Weld
Points

(Outside)

(Middle)

(Inside)

HINT:

Panel position symbols are as seen from

the working posture.

Spot Weld

Mig Plug
Weld

Spot MIG
Weld

INTRODUCTION –

Symbols

IN-5

Illustration of Weld Point Symbols

EXAMPLE:

INTRODUCTION

– Handling Precautions on Related Components

IN-6

HANDLING PRECAUTIONS ON RELATED COMPONENTS

1.

FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND SEAT BELT PRETENSIONER

The LEXUS RX300 is equipped with an SRS (Supplemental Restraint System), such as the driver airbag and
front passenger airbag and seat belt pretensioners.
Failure to carry out service operations in the correct sequence could cause the supplemental restraint sys-
tem to unexpectedly deploy during servicing, possibly leading to a serious accident.
Further, if a mistake is made in servicing the supplemental restraint system, it is possible the SRS may fail to
operate when required. Before servicing (including removal or installation of parts, inspection or replace-
ment), be sure to read the following items carefully, then follow the correct procedure described in this
manual.

D Malfunction symptoms of the supplemental restraint system are difficult to confirm, so the diag-

nostic trouble codes become the most important source of information when troubleshooting.
When troubleshooting the supplemental restraint system, always inspect the diagnostic trouble
codes before disconnecting the battery.

D Work must be started after 90 seconds from the time the ignition switch is turned to the ”LOCK”

position and the negative (–) terminal cable is disconnected from the battery.
(The supplemental restraint system is equipped with a back-up power source so that if work is
started within 90 seconds of disconnecting the negative (–) terminal cable from the battery, the SRS
may deploy.)
When the negative (–) terminal cable is disconnected from the battery, memory of the clock and au-
dio systems will be cancelled. So before starting work, make a record of the contents memorized by
the audio memory system.
Then when work is finished, reset the clock and audio systems as before.
To avoid erasing the memory of each memory system, never use a back-up power supply from out-
side the vehicle.

D Even in cases of a minor collision where the SRS does not deploy, the passenger’s airbag assembly,

the steering wheel pad and seat belt pretensioners should be in spected.

D Never use SRS parts from another vehicle. When replacing parts, replace them with new parts.
D Before repairs, remove the airbag sensor if shocks are likely to be applied to the sensor during re-

pairs.

D Never disassemble and repair the airbag sensor assembly, steering wheel pad in order to reuse it.
D If the airbag sensor assembly, steering wheel pad have been dropped, or if there are cracks, dents or

other defects in the case, bracket or connector, replace them with new ones.

D Do not expose the airbag sensor assembly, steering wheel pad directly to hot air or flames.
D Use a volt/ohmmeter with high impedance (10 kΩ/V minimum) for troubleshooting of the electrical

circuit.

D Information labels are attached to the periphery of the SRS components. Follow the instructions on

the notices.

D After work on the supplemental restraint system is completed, check the SRS warning light.

INTRODUCTION

– Handling Precautions on Related Components

IN-7

D Before repairing the body, remove the SRS parts if, during repair, shocks are likely to be applied to

the sensors due to vibrations of the body or direct tapping with tools or other parts.

D Do not expose the SRS parts directly to hot air or flames.

NOTICE:
1)

The maximum ambient temperature tolerance is 120

_C (248_F) for the front airbag sensor,

105

_C (221_F) for the center airbag sensor assembly and 93_C (200_F) for the steering wheel

pad, and front passenger airbag assembly. If it is possible that the ambient temperature may
reach or exceed the temperature limit, remove the sensors and the steering wheel pad from
the vehicle or protect them with a hot insulation material before staring work.

2)

Prior to welding, remove adjacent SRS parts form the vehicle or protect them with fire-proof
covers.

D If the vehicle is damaged, visually inspect for damage to the steering wheel pad using the inspection

procedures described in section RS of the repair manual for the relevant model year.

STEERING WHEEL PAD (with Airbag)

D When removing the steering wheel pad or handling a new steering wheel pad, it should be placed

with the pad top surface facing up.
In this case, the twin-lock type connector lock lever should be in the locked state and care should be
taken to place it so the connector will not be damaged. In addition do not store a steering wheel pad
on top of another one. Storing the pad with its metallic surface up may lead to a serious accident if
the airbag inflates for some reason.

D Never measure the resistance of the airbag squib. (This may cause the airbag to deploy, which is

very dangerous.)

D Grease should not be applied to the steering wheel pad and the pad should not be cleaned with de-

tergents of any kind.

D Store the steering wheel pad where the ambient temperature remains below 93_C (200_F), without

high humidity and away from electrical noise.

D When using electric welding, first disconnect the airbag connector (yellow color and 2 pins) under

the steering column near the combination switch connector before starting work.

D When disposing of a vehicle or the steering wheel pad alone, the airbag should be deployed using

an SST before disposal.
Carry out the operation in a safe place away from electrical noise.

FRONT PASSENGER AIRBAG ASSEMBLY

D Always store a removed or new front passenger airbag assembly with the airbag deployment direc-

tion facing up. Storing the airbag assembly with the airbag deployment direction facing down could
cause a serious accident if the airbag inflates.

D Never measure the resistance of the airbag squib.

(This may cause the airbag deploy, which is very dangerous.)

D Grease should not be applied to the front passenger airbag assembly and the airbag door should

not be cleaned with detergents of any kind.

D Store the airbag assembly where the ambient temperature remains below 93_C (200_F), without

high humidity and away from electrical noise.

D When using electric welding, first disconnect the airbag connector (yellow color and 2 pins)

installed on the glove compartment finish plate at the left side of the glove compartment before
starting work.

D When disposing of a vehicle or the airbag assembly alone, the airbag should be deployed using an

SST before disposal.
Perform the operation in a safe place away from electrical noise.

INTRODUCTION

– Handling Precautions on Related Components

IN-8

SEAT BELT PRETENSIONER

D Before doing any operation which will apply a strong shock to the vehicle, or before removing the

seat belt pretensioner, be sure to apply the sensor shock.

D Never disassemble the seat belt pretensioner.
D Do not subject the seat belt pretensioner to shocks or bring magnets close to it.
D Do not expose the seat belt pretensioner to hight temperature or fire.
D Do not drop the seat belt pretensioner. Never use a seat belt pretensioner which has been dropped.
D Never install the seat belt pretensioner in another vehicle.
D Store removed seat belt pretensioners on a flat, stable surface.
D Afer frontal collision, always check whether the seat belt pretensioners have been activated.
D When disposing of a vehicle or the pretensioner by itself, always activate the pretensioner before

disposal.

D The seat belt pretensioner is hot when activated, so let it cool down fully before you dispose of it.

Never apply water to the seat belt pretensioner.

AIRBAG SENSOR ASSEMBLY

D Never reuse the airbag sensor assembly involved in a collision when the SRS has deployed.
D The connectors to the airbag sensor assembly should be connected or disconnected with the sen-

sor mounted on the floor. If the connectors are connected or disconnected while the airbag sensor
assembly is not mounted to the floor, it could cause undesired ignition of the supplemental restraint
system.

D Work must be started after 90 seconds from the time the ignition switch is turned to the ”LOCK”

position and the negative (–) terminal cable is disconnected from the battery, even if only loosening
the set bolts of the airbag sensor assembly.

WIRE HARNESS AND CONNECTOR

D The SRS wire harness is integrated with the cowl wire harness assembly and floor wire harness as-

sembly. The wires for the SRS wire harness are encased in a yellow corrugated tube. All the connec-
tors for the system are also a standard yellow color. If the SRS wire harness becomes disconnected
or the connector becomes broken due to an accident, etc., repair or replace it as shown on page.

2.

COMPONENTS ADJACENT TO THE BODY PANELS

Various types of component parts are mounted directly on or adjacently to the body panels. Strictly
observe the following precautions to prevent damaging these components and the body panels dur-
ing handling.
D Before repairing the body panels, remove their components or apply protective covers over the

components.

D Before prying components off using a screwdriver or a scraper, etc., attach protective tape to the

tool tip or blade to prevent damaging the components and the body paint.

D Before removing components from the outer surface of the body, attach protective tape to the body

to ensure no damage to painted areas.

HINT:

Apply touch-up paint to any damaged paint surfaces.

D Before drilling or cutting sections, make sure that there are no wires, etc. on the reverse side.