Diagnostic Procedure
WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
- Perform system operation check and observe other warning lights. See SYSTEM OPERATION CHECK . If other warning lights DO NOT illuminate, diagnose and repair instrument cluster. If other warning lights illuminate, go to next step.
- Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Deactivate link system. See LINK SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Access air bag sensor assembly and disconnect connector A24 (center connector). See AIR BAG SENSOR ASSEMBLY under REMOVAL & INSTALLATION. Reconnect negative battery cable. Turn ignition switch to ACC or ON position. Measure voltage between ground and air bag sensor assembly connector A24, terminal No. 6 (circuit IG1, Violet/White wire). See Fig 1. Measure voltage between ground and air bag sensor assembly connector A24, terminal No. 5 (circuit IG2, Black/Orange wire). If 10-14 volts is not present, check harness between battery and air bag sensor assembly, check battery and charging system and repair as necessary. See WIRING DIAGRAMS . If 10-14 volts is present, go to next step.
- Turn ignition switch to LOCK position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Reconnect 3 air bag sensor assembly connectors. Leave other components disconnected. Reconnect negative battery cable and wait at least 2 seconds. Turn ignition switch to ACC or ON position. If AIR BAG warning illuminates, system operation is normal at this time. Check for intermittent fault. See AIR BAG WARNING LIGHT INTERMITTENT . If AIR BAG warning light does not illuminate, check for poor connection at air bag sensor assembly connector A24. If connection is okay, replace air bag sensor assembly.