Disabling & Activating Air Bag System: Notes
WARNING: This page is about a different car, the 1994 Lexus LS 400. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Back-up power supply retains SRS voltage for about 90 seconds after battery is disconnected. After disabling SRS, wait at least 2 minutes before servicing SRS. Servicing SRS before 90 seconds may cause accidental air bag deployment and possible personal injury.