Diagnostic Procedure
WARNING: This page is about a different car, the 2004 Toyota Matrix and 2004 Toyota Corolla. 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. Access air bag sensor assembly and ensure all harness connectors are properly connected. See AIR BAG SENSOR ASSEMBLY under REMOVAL & INSTALLATION. Access instrument cluster and ensure harness connector is properly connected. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. If connectors are properly connected, go to next step. If connectors are not properly connected, reconnect connectors.
- Disconnect instrument cluster harness connector C9 on Corolla models, and C11 on Matrix models. On all models, connect negative battery cable. Wait at least 2 seconds. Turn ignition switch to ON position. Wait at least 6 seconds. On Corolla models, measure voltage between ground and instrument cluster connector C9, terminal No. 39 (circuit SW, Black Yellow wire). See Fig 1. On Matrix models, measure voltage between ground and instrument cluster connector C11, terminal No. 6 (circuit SW, Black Yellow wire). If voltage is more than 8 volts, go to next step. If voltage is less than 8 volts, replace instrument cluster.
- Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait at least 90 seconds. Disconnect air bag sensor assembly connector A13. Measure resistance between ground and air bag sensor assembly connector A13, terminal No. 3 (circuit LA, Black Yellow wire). See Figure. If resistance is less than one megohm, repair or replace wire harness between instrument cluster and air bag sensor assembly. See WIRING DIAGRAMS . If resistance is more than one megohm, go to next step.
- On Corolla models, measure resistance between instrument cluster connector C9, terminal No. 39 (circuit SW, Black Yellow wire) and air bag sensor assembly connector A13, terminal No. 3 ((circuit LA, Black Yellow wire). On Matrix models, measure resistance between instrument cluster connector C11, terminal No. 6 (circuit SW, Black Yellow wire) and air bag sensor assembly connector A13, terminal No. 3 (circuit LA, Black Yellow wire). On both models, if resistance in more than one ohm, repair or replace wire harness between instrument cluster and air bag sensor assembly. If resistance in less than one ohm, replace air bag sensor assembly.