Air Bag Systems: Service Precautions

SUPPLEMENTAL RESTRAINT SYSTEM

PRECAUTION

CAUTION:
- LEXUS LS430 is equipped with SRS, which consists of a driver airbag, front passenger airbag, driver knee airbag, front passenger knee airbag, side airbag and curtain shield 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 mistake 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 replacement), be sure to read the following items carefully, then follow the correct procedures indicated.
- Wait at least 90 seconds after 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 after disconnecting the negative (-) terminal cable of the battery, the SRS may be deployed.)
- Do not expose the horn button assembly, front passenger airbag assembly, instrument panel airbag assembly lower No.1, instrument panel airbag assembly lower No.2, airbag sensor assembly center, airbag sensor front, front seat airbag assembly, side airbag sensor assembly, curtain shield airbag assembly, airbag sensor rear or seat position airbag sensor directly to hot air or flames.

NOTE:
- Malfunction symptoms of the SRS are difficult to confirm, so DTCs are the most important source of information when troubleshooting. When troubleshooting the SRS, always inspect DTCs before disconnecting the battery.
- Even in the case of a minor collision when the SRS does not deploy, the horn button assembly, front passenger airbag assembly, instrument panel airbag assembly lower No.1, instrument panel airbag assembly lower No.2, airbag sensor assembly center, airbag sensor front, front seat airbag assembly, side airbag sensor assembly, curtain shield airbag assembly, airbag sensor rear and seat position airbag sensor should be inspected.
- Before repair work, remove the airbag sensor if any kind of shock is likely to occur to the airbag sensor during the operation.
- Never use SRS parts from another vehicle. When replacing the parts, replace them with new ones.
- Never disassemble or repair the horn button assembly, front passenger airbag assembly, instrument panel airbag assembly lower No.1, instrument panel airbag assembly lower No.2, airbag sensor assembly center, airbag sensor front, front seat airbag assembly, side airbag sensor assembly, curtain shield airbag assembly, airbag sensor rear or seat position airbag sensor in order to reuse it.
- If the horn button assembly, front passenger airbag assembly, instrument panel airbag assembly lower No.1, instrument panel airbag assembly lower No.2, airbag sensor assembly center, airbag sensor front, front seat airbag assembly, side airbag sensor assembly, curtain shield airbag assembly, airbag sensor rear or seat position airbag sensor has been dropped, or if there are any cracks, dents or other defects in the case, bracket or connector, replace it with a new one.
- Use a volt/ohmmeter with high impedance (10 kOhm/V minimum) for troubleshooting the electrical circuits.
- Information labels are attached to the periphery of the SRS components. Follow the instructions in the caution.
- After work on the SRS is completed, perform the SRS warning light check.
- 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 in the audio memory system. When work is finished, reset the audio system as it was before and adjust the clock. Never use a back-up power supply from outside the vehicle to avoid erasing the memory in each memory system.
- If the vehicle is equipped with a mobile communication system, refer to the Vehicle; Service Precautions.


PRECAUTION

NOTE: When disconnecting the negative (-) battery terminal, initialize the following system after the terminal is reconnected.
- Front Power Seat Control System

1. HANDLING PRECAUTIONS FOR AIRBAG SENSOR

HINT: The airbag sensor assembly center, airbag sensor front LH, airbag sensor front RH, side airbag sensor assembly LH, side airbag sensor assembly RH, airbag sensor rear LH, airbag sensor rear RH and seat position airbag sensor are collectively referred to as the airbag sensor.

a. Before starting the following operations, wait at least 90 seconds after disconnecting the negative (-) terminal of the battery:
1. Replacement of the airbag sensor.
2. Adjustment of the front/rear doors of the vehicle equipped with the side airbag and curtain shield airbag (fitting adjustment).

b. When connecting or disconnecting the airbag sensor connector, ensure that each sensor is installed in the vehicle.
c. Do not use an airbag sensor which has been dropped during the operation or transportation.
d. Do not disassemble the airbag sensor.

2. INSPECTION PROCEDURE FOR VEHICLE INVOLVED IN ACCIDENT
a. When the airbag has not deployed, confirm the DTC by checking the SRS warning light. If there is any malfunction in the SRS airbag system, perform troubleshooting.
b. When any of the airbags have deployed, replace the airbag sensor and check the installation condition.