Lexus SC300 / Lexus SC400. Manual - part 57

REPLACEMENT REQUIREMENTS

In the following cases, replace the front airbag sensor.
NOTICE: For replacement of the front airbag sensor, see page 

AB–16

, “REMOVAL AND

INSTALLATION”.

•

If the airbag has been deployed in a collision.
(Replace both the left and right airbag sensors.)

•

If the front airbag sensor has been found to be faulty in troubleshooting.

•

If the front airbag sensor has been found to be faulty during the check in item 2–(b).

•

If the front airbag sensor has been dropped.

Center Airbag Sensor Assembly

INSPECTION ITEMS

1. 

VEHICLES NOT INVOLVED IN A COLLISION

•

Perform a diagnostic system check (See page 

AB–30

).

VEHICLES INVOLVED IN A COLLISION
IF THE AIRBAG IS NOT DEPLOYED

•

Perform a diagnostic system check (See page 

AB–30

).

IF THE AIRBAG IS DEPLOYED

•

Replace the airbag sensor assembly certainly.

AB–11

SRS

 AIRBAG   –   Inspection Items and Replacement Requirements

Wire Harness and Connector

HINT: The wires for the airbag wire harness are encased in a yellow corrugated tube and all the connectors in
the system are a standard yellow color.

INSPECTION ITEMS

1. 

VEHICLES NOT INVOLVED IN A COLLISION

•

Perform a diagnostic system check (See page 

AB–30

).

2. 

VEHICLES INVOLVED IN A COLLISION
(a)  Perform a diagnostic system check (See page 

AB–30

).

(b)  If there is a break in any of the wires in the airbag system wire harness, or if conductors are exposed.
(c)  If the airbag system wire harness connectors are cracked or chipped.

REPLACEMENT REQUIREMENTS

In the following cases, replace the wire harness or connector.

•

If any part of the airbag system wire harness or any connector has been found to be faulty in trouble-
shooting.

•

If any part of the airbag system wire harness or any connector has been found to be faulty during the
check in item 2–(b) or (c).

NOTICE: If the wire harness used in the airbag system is damaged, replace the whole wire harness
assembly.
When the connector to the airbag front sensors can be repaired alone (when there is no damage
to the wire harness), use the repair wire specially designed for the purpose (See page 

AB–20

).

AB–12

SRS

 AIRBAG   –   Inspection Items and Replacement Requirements

PREPARATION

SST (SPECIAL SERVICE TOOLS)

09082–00700

SRS

 Airbag

Deployment Tool

09213–31021

Crankshaft Pulley
Puller

09843–18020

Diagnosis Check
Wiring

Steering wheel

RECOMMENDED TOOLS

09042–00010

Torx Socket
T30

09042–00020

Torx Socket
T30

09082–00015

TOYOTA
Electrical Tester

Center airbag sensor assembly

Steering wheel pad

EQUIPMENT

Part Name

Note

Torque wrench

AB–13

SRS

 AIRBAG   –   Preparation

REMOVAL AND INSTALLATION OF
COMPONENT PARTS

Steering Wheel Pad and Spiral Cable

Removal and install the parts as shown.

(MAIN POINTS OF REMOVAL AND
INSTALLATION)

CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the LOCK position and the negative (–) terminal
cable is disconnected from the battery (See page 

AB–2

).

NOTICE:

•

If the wiring connector of the airbag system is discon-
nected with the ignition switch at ON or ACC, diagnostic
codes will be recorded.

•

Never use airbag parts from another vehicle. When re-
placing parts, replace with new parts.

1. 

REMOVE STEERING WHEEL PAD
(a)  Remove negative terminal (–) from the battery.
(b)  Place the front wheels facing straight ahead.
(c)  Using a torx wrench, loosen the four screws.
Torx wrench: T30 (Part No. 09042–00010 or locally manufac-
tured tool)
(d)  Loosen the torx screws until the groove along the screw

circumference catches on the screw case.

AB–14

SRS

 AIRBAG   –   Removal and Installation of Component Parts