For Vehicles Equipped With SRS Airbag and Seat Belt Pretensioner
FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND SEAT BELT PRETENSIONERThe LEXUS SC 430 is equipped with a Supplemental Restraint System (SRS) and seat belt pretensioner.
CAUTION: Failure to carry out the service operations in the correct sequence could cause the SRS to unexpectedly deploy during servicing and lead to serious injury.
Furthermore, if a mistake is made when servicing the SRS, it is possible that the SRS may fail to operate properly. Before servicing (including removal or installation of parts, inspection or replacement), be sure to read the following carefully.
a. GENERAL NOTICE
1. As the malfunction symptoms of the SRS are difficult to confirm, the Diagnostic Trouble Codes (DTCs) become the most important source of information when troubleshooting. When troubleshooting the SRS, always check the DTCs before disconnecting the battery.
2. Work must be started at least 90 seconds after the ignition switch is turned OFF and after the cable is disconnected from the negative (-) battery terminal.
(The SRS is equipped with a backup power source. If work is started within 90 seconds after turning the ignition switch OFF and disconnecting the cable from the negative (-) battery terminal, the SRS may deploy).
When the cable is disconnected from the negative (-) battery terminal, clock and audio system memory is erased. Before starting work, make a note of the settings of each memory system. When work is finished, reset the clock and audio systems as before.
CAUTION: Never use a backup power source (battery or other) to avoid erasing system memory. The backup power source may power the SRS and cause it to deploy.
3. In minor collisions where the SRS does not deploy, the horn button assembly, front passenger airbag assembly, front seat airbag assembly, and seat belt pretensioner should be inspected before further use of the vehicle.
4. Never use SRS parts from another vehicle. When replacing parts, use new parts.
5. Before repairs, remove the airbag sensor assemblies if impacts are likely to be applied to the sensors during repairs.
6. Never disassemble and repair the airbag sensor assemblies, horn button assembly, front passenger airbag assembly, front seat airbag assembly, curtain shield airbag assembly or seat belt pretensioner.
7. Replace the airbag sensor assemblies, horn button assembly, front passenger airbag assembly, front seat airbag assembly or curtain shield airbag assembly: 1) if damage has occurred from being dropped, or 2) if there are cracks, dents or other defects in the case, bracket or connector.
8. Do not directly expose the airbag sensor assemblies, horn button assembly, front passenger airbag assembly, front seat airbag assembly, curtain shield airbag assembly or seat belt pretensioner to hot air or flames.
9. Use a voltmeter/ohmmeter with high impedance (10 kOhm/V minimum) for troubleshooting electrical circuits.
10. Information labels are attached to the SRS components. Follow the instructions on the labels.
11. After work on the SRS is completed, check the SRS warning lamp.
b. SPIRAL CABLE (in Combination Switch)
1. The steering wheel must be fitted correctly to the steering column with the spiral cable at the neutral position, as cable disconnection and other problems may occur.
c. HORN BUTTON ASSEMBLY (with Airbag)
1. When removing the horn button or handling a new horn button, it should be placed with the pad surface facing up. See illustration. Placing the horn button with the pad surface facing down may lead to a serious accident if the airbag accidently inflates. Also, do not place anything on top of the horn button.
2. Never measure the resistance of the airbag squib. This may cause the airbag to inflate, which could cause serious injury.
3. Grease or detergents of any kind should not be applied to the steering wheel pad.
4. Store the horn button in an area where the ambient temperature is below 93 °C (200 °F), the humidity is not high and electrical noise is not nearby.
5. When using electric welding anywhere on the vehicle, disconnect the airbag ECU connectors (4 pins). These connectors contain shorting springs. This feature reduces the possibility of the airbag deploying due to currents entering the squib wiring.
6. When disposing of the vehicle or the horn button by itself, the airbag should be inflated using SST before disposal. Activate in a safe place away from electrical noise.
d. FRONT PASSENGER AIRBAG ASSEMBLY
1. Always place a removed or new airbag assembly with the airbag inflation direction facing up. Placing the airbag assembly with the airbag inflation direction facing down could cause a serious accident if the airbag inflates.
2. Never measure the resistance of the airbag squib. This may cause the airbag to inflate, which could cause serious injury.
3. Grease or detergents of any kind should not be applied to the airbag assembly.
4. Store the airbag assembly in an area where the ambient temperature is below 93 °C (200 °F), the humidity is not high and electrical noise is not nearby.
5. When using electric welding anywhere on the vehicle, disconnect the airbag ECU connectors (4 pins). These connectors contain shorting springs. This feature reduces the possibility of the airbag deploying due to currents entering the squib wiring.
6. When disposing of a vehicle or the airbag assembly unit by itself, the airbag should be deployed using SST before disposal. Activate in a safe place away from electrical noise.
e. FRONT SEAT AIRBAG ASSEMBLY
1. Always place a removed or new airbag assembly with the airbag inflation direction facing up. Placing the airbag assembly with the airbag inflation direction facing down could cause a serious accident if the airbag inflates.
2. Never measure the resistance of the airbag squib. This may cause the airbag to inflate, which could cause serious injury.
3. Grease or detergents of any kind should not be applied to the airbag assembly.
4. Store the airbag assembly in an area where the ambient temperature is below 93 °C (200 °F), the humidity is not high and electrical noise is not nearby.
5. When using electric welding anywhere on the vehicle, disconnect the airbag ECU connectors (2 pins). These connectors contain shorting springs. This feature reduces the possibility of the airbag deploying due to currents entering the squib wiring.
6. When disposing of a vehicle or the airbag assembly unit by itself, the airbag should be deployed using SST before disposal. Activate in a safe place away from electrical noise.
f. SEAT BELT PRETENSIONER
1. Never measure the resistance of the seat belt pretensioner. This may cause the seat belt pretensioner to activate, which could cause serious injury.
2. Never disassemble the seat belt pretensioner.
3. Never install the seat belt pretensioner on another vehicle.
4. Store the seat belt pretensioner in an area where the ambient temperature is below 80 °C (176 °F), the humidity is not high and electrical noise is not nearby.
5. When using electric welding anywhere on the vehicle, disconnect the airbag ECU connectors (2 pins). These connectors contain shorting springs. This feature reduces the possibility of the seat belt pretensioner deploying due to currents entering the squib wiring.
6. When disposing of a vehicle or the seat belt pretensioner unit by itself, the seat belt pretensioner should be activated before disposal. Activate in a safe place away from electrical noise.
7. As the seat belt pretensioner is hot after being activated, allow some time for it to cool down sufficiently before disposal. Never apply water to try to cool down the seat belt pretensioner.
8. Grease, detergents, oil or water should not be applied to the front seat outer belt.
g. AIRBAG SENSOR ASSEMBLY
1. Never reuse an airbag sensor assembly that has been involved in a collision where the SRS has deployed.
2. The connectors to the airbag sensor assembly should be connected or disconnected with the sensor mounted on the floor. If the connectors are connected or disconnected while the airbag sensor assembly is not mounted on the floor, the SRS may activate.
3. Work must be started at least 90 seconds after the ignition switch is turned OFF and after the cable is disconnected from the negative (-) battery terminal, even if only loosening the set bolts of the airbag sensor assembly.
h. WIRE HARNESS AND CONNECTOR
1. The SRS wire harness is integrated with the instrument panel wire harness assembly. All the connectors in the system are a standard yellow color. If the SRS wire harness becomes disconnected or the connector becomes broken, repair or replace it.