SEAT BELT SYSTEM > Seat Belt Warning System

INSPECTION

TROUBLE SYMPTOM:

• Seat belt warning light does illuminate or it remains illuminating.

• Buzzer does not beep.

STEPCHECKYESNO

1.CHECK HARNESS BETWEEN IMMOBILIZER UNIT AND CHASSIS GROUND.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from the immobilizer unit.

3) Measure the resistance between the immobilizer unit harness connector and chassis ground.

Connector & terminal

(B141) No. 15 — Chassis ground:

(B141) No. 25 — Chassis ground:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between the immobilizer unit and chassis ground.

2.CHECK IMMOBILIZER UNIT POWER SOURCE.

1) Turn the ignition switch to ON.

2) Measure the resistance between the immobilizer unit connector and chassis ground.

Connector & terminal

(B141) No. 24 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Repair the open or short circuit of harness, or poor contact of the connector, between the immobilizer unit and battery.

3.CHECK SEAT BELT SWITCH AND HARNESS.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from the immobilizer unit.

3) Pull out the tongue plate from the seat belt buckle.

4) Measure the resistance between the immobilizer unit harness connector and chassis ground.

Connector & terminal

(B141) No. 7 — Chassis ground:

Is the resistance less than 1 Ω?

Repair the short circuit of harness between the immobilizer unit connector and chassis ground.

4.CHECK SEAT BELT SWITCH AND HARNESS.

1) Turn the ignition switch to OFF.

2) Insert the tongue plate to the seat belt buckle.

3) Measure the resistance between the immobilizer unit connector and chassis ground.

Connector & terminal

(B141) No. 7 — Chassis ground:

Is the resistance 1 MΩ or more?

5.CHECK HARNESS BETWEEN IMMOBILIZER UNIT AND SEAT BELT SWITCH.

Measure the resistance of harness between the immobilizer unit connector and seat belt switch.

Connector & terminal

LHD model

(B141) No. 7 — (R8) No. 2:

RHD model

(B141) No. 7 — (R8) No. 1:

Is the resistance less than 1 Ω?

Repair the open circuit of harness, or poor contact of the connector, between the immobilizer unit connector and seat belt switch.

6.CHECK HARNESS BETWEEN SEAT BELT SWITCH AND CHASSIS GROUND.

Measure the resistance of harness between seat belt switch and chassis ground.

Connector & terminal

LHD model

(R8) No. 1 — Chassis ground:

RHD model

(R8) No. 2 — Chassis ground:

Is the resistance less than 1 Ω?

Repair open circuit of harness between seat belt switch and chassis ground.

7.CHECK SEAT BELT SWITCH.

1) Pull out the tongue plate from the seat belt buckle.

2) Measure the resistance between seat belt switch terminals.

Terminals

(R8) No. 1 — (R8) No. 2:

Is the resistance less than 1 Ω?

Replace the inner seat belt assembly.

8.CHECK SEAT BELT SWITCH.

1) Insert the tongue plate to the seat belt buckle.

2) Measure the resistance between seat belt switch terminals.

Terminals

(R8) No. 1 — (R8) No. 2:

Is the resistance 1 MΩ or more?

Replace the inner seat belt assembly.

9.CHECK SPEEDOMETER OPERATION IN COMBINATION METER.

Check that the speedometer needle displays the speed correctly.

Does the speedometer operate normally?

Check the speedometer circuit.

10.CHECK VEHICLE.

Check whether the vehicle is an MT model.

Is the vehicle an MT model?

11.CHECK HARNESS BETWEEN VEHICLE SPEED SENSOR AND IMMOBILIZER UNIT.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from vehicle speed sensor.

3) Measure the resistance between the vehicle speed sensor harness connector and immobilizer unit connector.

Connector & terminal

(B17) No. 1 — (B141) No. 9:

Is the resistance less than 10 Ω?

Repair the open circuit of harness between the vehicle speed sensor and immobilizer unit.

12.CHECK HARNESS BETWEEN VEHICLE SPEED SENSOR AND IMMOBILIZER UNIT.

Measure the resistance between the immobilizer unit harness connector and chassis ground.

Connector & terminal

(B141) No. 9 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the short circuit of harness.

13.CHECK HARNESS BETWEEN TCM AND IMMOBILIZER UNIT.

1) Turn the ignition switch to OFF.

2) Disconnect the following TCM connectors.

3) Measure the resistance between the TCM harness connector and immobilizer unit harness connector.

Connector & terminal

(B55) No. 21 — (B141) No. 9:

Is the resistance less than 10 Ω?

Repair the open circuit of harness between the TCM and immobilizer unit.

14.CHECK HARNESS BETWEEN TCM AND IMMOBILIZER UNIT.

Measure the resistance of harness between the immobilizer unit harness connector and chassis ground.

Connector & terminal

(B141) No. 9 — Chassis ground:

Is the resistance less than 10 Ω?

Repair the short circuit of harness.

15.CHECK IMMOBILIZER UNIT OUTPUT SIGNAL.

1) Turn the ignition switch to ON.

2) Measure the resistance between the immobilizer unit harness connector and chassis ground.

Connector & terminal

(B141) No. 19 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Check wiring harness and combination meter, then repair or replace them.

16.CHECK POOR CONTACT.

Check for poor contact in seat belt warning light circuit.

Is there poor contact?

Repair the poor contact.

17.CHECK IMMOBILIZER UNIT.

1) Connect all connectors.

2) Lift-up the vehicle and place it on rigid racks.

NOTE:

Raise all wheels off the floor.

3) Pull out the tongue plate from the seat belt buckle.

4) Start the engine and drive the vehicle at 19 km/h (12 MPH) or less.

NOTE:

The speed difference between front and rear wheels may illuminate the ABS warning light, but this does not indicate a malfunction. When the diagnosis is complete, the OBD system ABS memory delete procedure is executed.

Check if the seat belt warning light illuminates.

Does the seat belt warning light illuminate?

Replace the immobilizer unit.

18.CHECK IMMOBILIZER UNIT.

1) Connect all connectors.

2) Lift-up the vehicle and place it on rigid racks.

NOTE:

Raise all wheels off the floor.

3) Pull out the tongue plate from the seat belt buckle.

4) Start the engine and drive the vehicle at more than 25 km/h (16 MPH).

NOTE:

The speed difference between front and rear wheels may illuminate the ABS warning light, but this does not indicate a malfunction. When the diagnosis is complete, the OBD system ABS memory delete procedure is executed.

Check if the seat belt warning light illuminates and the buzzer sounds.

Does the seat belt warning light illuminate and the buzzer sound?

A temporary poor contact of connector or harness may be the cause. Check for poor contact.

Replace the immobilizer unit.