Possible Causes
WARNING: This page is about a different car, the 2004 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.
Seat belt warning light circuit short to power or open can be caused by instrument cluster malfunction, improper connection of connectors between instrument cluster and SAS control module, open or short circuit in wiring harness between fuse No. 1 and SAS control module or SAS control module malfunction.
- Inspect for continuity between fuse No. 1 & instrument cluster
Connect negative battery cable. Turn ignition switch to ON position. Measure voltage between ground and instrument cluster connector No. 2, terminal No. 2A. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. See Figure . If voltage is more than 9 volts, go to next step. If voltage is less than 9 volts, replace wiring harness fuse No. 1 and instrument cluster. - Inspect wiring harness between instrument cluster & SAS control module
Turn ignition switch to LOCK position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Remove steering column cover and disconnect clockspring connector. Remove glove box and disconnect passenger-side air bag module connectors. Disconnect right and left side air bag module connectors. See SIDE AIR BAG MODULE under REMOVAL & INSTALLATION. Disconnect right and left side curtain air bag module connectors. See SIDE CURTAIN AIR BAG MODULE under REMOVAL & INSTALLATION. Remove right and left rear door lower trims and disconnect seat belt pretensioner connectors. See SEAT BELT PRETENSIONER under REMOVAL & INSTALLATION. Disconnect instrument cluster connectors. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Measure for short to ground, short to power or open circuit between SAS control module connector No. 1, terminal No. 1E and instrument cluster connector No. 2, terminal No. 2A. See Figure & Figure . If short to ground, short to power or open circuit is detected, replace wiring harness. If short to ground, short to power or open circuit is not detected, go to next step. - Inspect seat belt warning light
Connect instrument cluster connectors. Connect a jumper wire between ground and instrument cluster connector No. 2, terminal No. 2G. Connect negative battery cable. Turn ignition switch to ON position. Inspect seat belt warning light. If seat belt warning light is illuminated and performing present malfunction diagnosis, replace SAS control module. See SAS CONTROL MODULE under REMOVAL & INSTALLATION. If seat belt warning light is illuminated and performing past malfunction diagnosis, test is complete. If seat belt warning light is not illuminated, replace instrument cluster.