Test No. 27: Seat Belt Warning Light Does Not Operate
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
- Driver and passenger seat belt warning lights are located on service reminder indicators and warning buzzer display of multi-display information center at center of instrument panel, just above air vent assembly. To check seat belt warning light bulb circuit, turn ignition off and disconnect seat belt buckle switch 2-pin electrical connector. Using a fused-jumper wire, ground Red/White wire at terminal No. 1 of seat belt buckle switch 2-pin electrical connector. Warning light should illuminate. If warning light illuminates, go to next step. If warning light does not illuminate, check light bulb. If light bulb is okay, go to next step. If light bulb is defective, replace light bulb. After repairs, perform confirmation test. See CONFIRMATION TEST .
- Check seat belt buckle switch. See SEAT BELT BUCKLE SWITCH under COMPONENT TESTS under INSTRUMENT PANELS - AVALON article in ACCESSORIES & EQUIPMENT. If seat belt buckle switch is okay, go to next step. If seat belt buckle switch is defective, replace seat belt buckle switch. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
- Check body control ECU ground circuits. See BODY COMPUTER in SYSTEM WIRING DIAGRAMS article. If ground circuits are faulty, repair and retest system. If ground circuits are okay, substitute original body control ECU with a known-good unit and recheck system operation. If system operates properly, original body control ECU was defective. If system still does not operate properly, perform body control ECU pin voltage check. See BODY CONTROL ELECTRONIC CONTROL UNIT under PIN VOLTAGE TESTS. Check wiring harness and electrical connectors for an intermittent problem. Repair wiring harnesses or connectors as necessary. If voltage values, harnesses and connectors are okay, replace body control ECU. After repairs, perform confirmation test. See CONFIRMATION TEST . If symptom is still present, go to next step.
- Check printed circuit board in multi-display information center for burned circuits, cracks in the circuit board or other problems which may prevent operation of seat belt warning light. If printed circuit board is okay, go to next step. If printed circuit board is defective, replace circuit board. See MULTI-DISPLAY INFORMATION CENTER under REMOVAL & INSTALLATION under INSTRUMENT PANELS - AVALON article in ACCESSORIES & EQUIPMENT.
- Check wiring harness and electrical connectors between battery and body control ECU, between body control ECU and suspect seat belt buckle switch, between body control ECU and multi-display information center, and all power and ground connections. See BODY COMPUTER , INSTRUMENT CLUSTER and WARNING SYSTEMS in SYSTEM WIRING DIAGRAMS article. If wiring harnesses or electrical connectors are defective, repair as necessary. After repairs, perform confirmation test. See CONFIRMATION TEST .