Seat Belt Warning System: Inspection

TROUBLE SYMPTOM:

Seat belt warning light does illuminate or it remains illuminating.
Buzzer does not beep.

DIAGNOSTIC PROCEDURE CHART

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN BODY INTEGRATED UNIT AND CHASSIS GROUND. Turn the ignition switch to OFF. Disconnect the connector from body integrated unit. Measure the resistance between body integrated unit harness connector and chassis ground. Connector & terminal (B281) No. 3 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 2.	Repair the open circuit of harness between the body integrated unit and chassis ground.
2 CHECK BODY INTEGRATED UNIT POWER SUPPLY. Turn the ignition switch to ON. Measure the voltage between body integrated unit connector and chassis ground. Connector & terminal (B281) No. 19 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 3.	Repair the open and short circuit of harness between body integrated unit and battery, and poor contact in connector.
3 CHECK SEAT BELT SWITCH AND HARNESS. Turn the ignition switch to OFF. Disconnect the connector from body integrated unit. Pull out the tongue plate from the driver's seat belt buckle. Measure the resistance between body integrated unit harness connector and chassis ground. Connector & terminal (B281) No. 3 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 4.	Repair the short circuit of harness between the body integrated unit connector and chassis ground.
4 CHECK SEAT BELT SWITCH AND HARNESS. Turn the ignition switch to OFF. Insert the tongue plate to the driver's seat belt buckle. Measure the resistance between body integrated unit connector and chassis ground. Connector & terminal (B281) No. 3 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 7.	Go to step 5.
5 CHECK HARNESS BETWEEN BODY INTEGRATED UNIT AND SEAT BELT SWITCH. Measure the resistance of harness between body integrated unit connector and seat belt switch. Connector & terminal (B281) No. 3 - (R8) No. 2:	Is the resistance less than 1 Ω?	Go to step 6.	Repair the open circuit of harness between body integrated unit connector and seat belt switch, and poor contact in connector.
6 CHECK HARNESS BETWEEN SEAT BELT SWITCH AND CHASSIS GROUND. Measure the resistance of harness between seat belt switch and chassis ground. Connector & terminal (R8) No. 1 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 7.	Repair open circuit of harness between seat belt switch and chassis ground.
7 CHECK SEAT BELT SWITCH. Pull out the tongue plate from the driver's seat belt buckle. Measure the resistance between seat belt switch terminals. Terminals (R8)No.1 - (R8)No.2:	Is the resistance less than 1 Ω?	Go to step 8.	Replace the inner belt assembly.
8 CHECK SEAT BELT SWITCH. Insert the tongue plate to the driver's seat belt buckle. Measure the resistance between seat belt switch terminals. Terminals (R8) No. 1 - (R8) No. 2:	Is the resistance more than 1 MΩ?	Go to step 9.	Replace the inner belt assembly.
9 CHECK COMBINATION METER. Turn the ignition switch to ON. Measure the voltage between combination meter and chassis ground. Connector & terminal (i10) No. 9 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 10 .	Check wiring harness and combination meter, then repair or replace them.
10 CHECK POOR CONTACT. Check for poor contact in seat belt warning light circuit.	Is there poor contact?	Repair the poor contact.	Go to step 11 .
11 CHECK THE BODY INTEGRATED UNIT. Connect all the connectors. Turn the ignition switch to ON. Pull out the tongue plate from the driver's seat belt buckle. Check if the seat belt warning light illuminates.	Does the seat belt warning light illuminate?	Go to step 12 .	Inspect the connector or harness. If not defective, replace the seat belt warning light bulb in the combination meter.
12 CHECK THE BODY INTEGRATED UNIT. Connect all the connectors. Turn the ignition switch to ON. Pull out the tongue plate from the driver's seat belt buckle. Check if the seat belt warning light illuminates and the buzzer sounds.	Does the seat belt warning light illuminate and the buzzer sound for 6 seconds?	A temporary poor contact of connector or harness may be the cause. Check for poor contact.	Replace the body integrated unit.