GENERAL DESCRIPTION The 1990 TOYOTA SUPRA for USA specifications is equipped with an SRS (Supplemental Restraint System) airbag. Failure to carry out service operations in the correct sequence could cause the airbag system to unexpectedly deploy during servicing, possibly leading to a serious accident. Further, if a mistake is made in servicing the airbag system, it is possible that the airbag 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 procedure described in the repair manual. 1. Malfunction symptoms of the airbag system are difficult to confirm, so the diagnostic codes become the most important source of information when troubleshooting. When troubleshooting the airbag system, always inspect the diagnostic codes before disconnecting the battery (See page AB-24). 2. Work must be started after approx. 20 seconds or longer from the time the ignition key is turned to the LOCK position and the negative (—) terminal cable is disconnected from the battery. (The airbag system is equipped with a back-up power source so that if work is started within 20 seconds of disconnecting the negative (—) terminal cable of the battery, the airbag may be deployed.) When the negative (—) terminal cable of the battery is disconnected, the clock and audio systems and radio systems will be cancelled. So before starting work, make a record of the contents memorized by each memory system. Restoration 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 outside the vehicle. 3. Even in cases of a minor collision where the airbag does not deploy, the front airbag sensors and the steering wheel pad should be inspected (See page AB-11). 4. Never use airbag parts from another vehicle. When replacing parts, replace them with new parts. 5. Before repairs, remove the airbag sensors if shocks are likely to be applied to the sensors during repairs. 6. The center airbag sensor assembly contains mercury. After performing replacement, do not destroy the old part. When scrapping the vehicle or replacing the center airbag sensor assembly itself, remove the center airbag sensor assembly and dispose of it as toxic waste. 7. Never disassemble and repair the front airbag sensors, center airbag sensor assembly or steering wheel pad in order to reuse it. 8. If the front airbag sensors, center airbag sensor assembly or 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. 9. Do not expose the front airbag sensors, center airbag sensor assembly or steering wheel pad directly to hot air or flames. 10. Use a volt/ohmmeter with high impedance (10 kΩ/V minimum) for troubleshooting of the electrical circuit. 11. Information labels are attached to the periphery of the airbag components. Follow the notices. 12. After work on the airbag system is completed, perform the airbag warning light check (See page AB-29).