Lexus ES300 (1997 year). Manual - part 652

202

ABS

A A A A A

D D D

B

B B

A A A A A

C C C

F F F F

1

2

J 3

J 4

BLACK

J27

J30

S10 BLUE

B B

B

A A

A A

A A A A A A A

J24

A

GRAY

J 8

B

GRAY

J 9

C C C

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203

SRS

NOTICE:

When inspecting or repairing the SRS, perform the operation in accordance with the following

precautionary instructions and the procedure and precautions in the Repair Manual for the applicable model 
year.

Malfunction symptoms of the SRS are difficult to confirm, so the DTCs become the most important
source of information when troubleshooting. When troubleshooting the SRS, always inspect the DTCs
before disconnecting the battery.

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 of
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 memorized by the
audio memory system. When work is finished, reset the audio systems as before and adjust the clock.
To avoid erasing the memory of each memory system, never use a back–up power supply from outside
the vehicle.

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.

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

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

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

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

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

Use a volt/ohmmeter with a 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 instructions on the
notices.

After work on the SRS is completed, check the SRS warning light.

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

204

SRS

The SRS has connectors which possess the functions described below:

1. SRS ACTIVATION PREVENTION MECHANISM

Each connector contains a short spring plate. When the 
connector is disconnected, the short spring plate
automatically connects the power source and grounding
terminals of the squib to preclude a potential difference
between the terminals.

2. ELECTRICAL CONNECTION CHECK MECHANISM

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

205

3. CONNECTOR TWIN–LOCK MECHANISM

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