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. 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 22/B1625 is not displayed, system is functioning normally at this time. Check for intermittent fault. See AIR BAG WARNING LIGHT INTERMITTENT . If DTC 22/B1625 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 right side air bag sensor. See SIDE AIR BAG SENSOR under REMOVAL & INSTALLATION. Ensure right side air bag sensor and air bag sensor assembly harness connectors are properly connected. If right side air bag sensor and air bag sensor assembly harness connectors are not properly connected, reconnect connectors and go to step 1. If right side air bag sensor and air bag sensor assembly harness connectors are properly connected, go to next step.
- Disconnect right side air bag sensor harness connector. Disconnect air bag sensor assembly harness connector A31. Connect jumper wire between Pink wire (circuit VUPR) and Gray wire (circuit ESR) on harness side of right side air bag sensor harness connector. Measure resistance between air bag sensor assembly harness connector A31, 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 right side air bag sensor and air bag sensor assembly.
- Remove jumper wire. Measure resistance between ground and air bag sensor assembly harness connector A31, 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 right side 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 A31, 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 right side air bag sensor and air bag sensor assembly.
- Measure resistance between ground and air bag sensor assembly harness connector A31, 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 side air bag sensor and air bag sensor assembly.
- Connect air bag sensor assembly connector A31. Remove left and right side air bag sensors. Install left side air bag sensor on right side and connect to right side air bag sensor harness connector. Install right side air bag sensor on left side and connect to left side 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 21/B1620 and 22/B1625 are not displayed, check for intermittent fault. If DTC 22/B1625 is displayed, replace air bag sensor assembly. If DTC 21/B1620 is displayed, replace right side air bag sensor.