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.
- Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM.
- Measure resistance between ground and air bag sensor assembly connector A25, terminals No. 1 (circuit SRF+, Green/Red wire) and No. 2 (circuit FSR-, Green/Black wire) individually. See Figure. If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair or replace wire harness between occupant detection sensor and air bag sensor assembly.
- Deactivate link system. See LINK SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Connect negative battery cable. Wait at least 2 seconds. Turn ignition switch to ON position. Measure voltage between ground and air bag sensor assembly connector A25, terminals No. 1 (circuit SRF+, Green/Red wire) and No. 2 (circuit FSR-, Green/Black wire) individually. If voltage is less than one volt, go to next step. If voltage is more than one volt, repair or replace wire harness between occupant detection sensor and air bag sensor assembly.
- Disconnect Gray, 6-pin occupant detection sensor connector, located under right front seat. Measure resistance between occupant detection sensor connector terminals No. 1 (circuit SRF+, Green/Red wire) and No. 4 (circuit FSR-, Green/Black wire). See Fig 1. If resistance is less than 50 k/ohms with passenger on seat and more than 50 k/ohms with passenger not on seat, go to next step. If resistance is not as specified, replace right seat cushion cover.
- Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Reconnect occupant detection sensor and air bag sensor assembly. Reconnect negative battery cable. Turn ignition switch to ACC or On position. Wait at least 20 seconds. Clear DTCs. See CLEARING CODES under DIAGNOSTICS. Turn ignition switch to LOCK position. Wait at least 20 seconds. Turn ignition switch to ACC or ON position. Wait at least 20 seconds. Retrieve DTCs. See RETRIEVING CODES under DIAGNOSTICS. If DTC 23/B1150 is retrieved, replace air bag sensor assembly. If DTC 23/B1150 is not retrieved, system is functioning properly at this time. Check for intermittent fault. See AIR BAG WARNING LIGHT INTERMITTENT .