Diagnostic Procedure
WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition switch to LOCK position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Reconnect air bag sensor assembly harness connectors. Turn ignition switch to ON position. Wait at least 60 seconds. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS) under DIAGNOSTICS. Turn ignition switch to LOCK position. Wait at least 20 seconds. Turn ignition switch to ON position. Wait at least 60 seconds. Retrieve DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) under DIAGNOSTICS. If DTC 23/B1630 is not displayed, system is functioning normally at this time. Check for intermittent fault. See AIR BAG WARNING LIGHT INTERMITTENT . If DTC 23/B1630 is displayed, go to next step.
- Turn ignition switch to LOCK position. Disconnect negative battery cable and wait at least 90 seconds. Access air bag sensor assembly. See AIR BAG SENSOR ASSEMBLY under REMOVAL & INSTALLATION. Access left rear air bag sensor. See REAR AIR BAG SENSOR under REMOVAL & INSTALLATION. Ensure left rear air bag sensor and air bag sensor assembly harness connectors are properly connected. If left rear air bag sensor and air bag sensor assembly harness connectors are not properly connected, reconnect connectors. If left rear air bag sensor and air bag sensor assembly harness connectors are properly connected, go to next step.
- Disconnect left rear air bag sensor harness connector. Disconnect air bag sensor assembly harness connector A30. Connect jumper wire between Brown wire (circuit VUCL) and Green/White wire (circuit ESCL) on harness side of left rear air bag sensor harness connector. Measure resistance between air bag sensor assembly harness connector A30, terminals No. 20 and 22. See Figure. If resistance is less than one ohm, go to next step. If resistance is more than one ohm, repair or replace harness or connector between left rear air bag sensor and air bag sensor assembly.
- Remove jumper wire. Measure resistance between air bag sensor assembly harness connector A30, terminals No. 20 and 22. If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair or replace harness or connector between left rear air bag sensor and air bag sensor assembly.
- Connect negative battery cable. Wait at least 2 seconds. Turn ignition switch to ON position. Measure voltage between ground and air bag sensor assembly harness connector A30, terminals No. 20 and 22. If voltage is less than one volt, go to next step. If voltage is more than one volt, repair or replace harness or connector between left rear air bag sensor and air bag sensor assembly.
- Measure resistance between ground and air bag sensor assembly harness connector A30, terminals No. 20 and 22. If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair or replace harness or connector between left rear air bag sensor and air bag sensor assembly.
- Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Remove right and left rear air bag sensors. Install right side air bag sensor on left side and connect to left rear air bag sensor harness connector. Install left rear air bag sensor on right side and connect to right rear air bag sensor harness connector. Connect negative battery cable. Wait at least 2 seconds. Turn ignition switch to ON position. Wait at least 60 seconds. Clear DTCs. Turn ignition switch to LOCK position. Wait at least 20 seconds. Turn ignition switch to ON position. Wait at least 60 seconds. Retrieve DTCs. If DTC 23/B1630 and 24/B1635 are not displayed, check for intermittent fault. If DTC 23/B1630 is displayed, replace air bag sensor assembly. If DTC 24/B1635 is displayed, replace left rear air bag sensor.